syn. oil

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  #1  
Old 05-21-02, 04:15 AM
gowitheflow
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syn. oil

I'm thinking about changing to synthetic oil in my '96 Corsica. Does synthetic make a significant difference in the life of your engine? Do I change the oil every 3000 mi. as with regular oil? Is there anything else I should know before I change over?

Thanks Gerald
 
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  #2  
Old 05-21-02, 08:12 AM
Joe_F
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On that car, no. Not worth the expense. It's not a race car or performance car. Waste of money in my belief.

Most cars will not benefit from the synthetic oil given the cost.

Change your oil every 3k or 3 months, use good quality oil and filters and you'll be fine.
 
  #3  
Old 05-21-02, 05:50 PM
otter_
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you shouldn't

extend your drain intervals using synthetic oil. Bear in mind that oil not only lubricates and cools the engine, it gets messed up with blow-by and other junk. The longer you wait to change it, the more junk in the oil.

As Joe_F states, "not worth it". Keep changing your oil at every 3K with a high quality product and you'll be OK.
 
  #4  
Old 05-22-02, 05:28 AM
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Run for your life, Joe; it's another oil vs. oil thread!!!!!!!! AAAAAHHHHHHHHHH! LOL!
 
  #5  
Old 05-22-02, 06:23 AM
Joe_F
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Lol. .

I guess we've got our vehicles with 100,000+ miles of severe service to prove our cases. Lol.
 
  #6  
Old 05-22-02, 07:30 AM
otter_
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relax...

re-read my post, I agree.
 
  #7  
Old 05-22-02, 08:45 AM
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Oil is your engines life blood

I hope this doesen't gey out of hand Joe. You remember the last time lol
If you want to pay allmost $5.00 per QT for oil and dump it every 2,500 to 3,000 miles then I say go for it. I am still wondering how I have 200,876 miles on my 81 Bonnie with that powerhouse of a V8 the 265 CI.

I have been using Castrol 20 W 50 with a half pint filter from the day I got it. This 265 is like the Energizer bunny, it just keeps on going.

I have read everything, I can get ahold of trying to find a reason to run Synthetic oil. It allways comes back to, you must change your oil at 3,000 miles or less.

That is forged in steel & trying to go longer between changes will hurt not help. As otter has allready said oil is a repository for pieces of junk floating around cutting and galling your parts.

I now know that Castrol does not make their own oil, so if I could find the same oil for 50 cents less I would buy it. As joe said, you don't have a racing engine. So I doubt you will need even a so called racing oil for good protection.

Today when I tear down an engine, it is fairly clean. Not so back in the 70s you could count on having sludge build up, the like most people don't see today.

My vote is for using a good name brand oil with a good filter and changing all, between 2,500 and 3,000 miles.

In the end Gerald it is up to you. If you want to use Mobil 1 and change it every 3,000 miles, it is a good oil. Just remember I don't see Mobil saying on their product, to exceed the MFR reccomended change reccomendations. So for me that is like saying, while synthetec oil may be a better oil, don't pass the 3,000 mile drain & filter change reccomendations.

Just one note about synthetic oil. I started racing two cycle Motorcycles in the late 60s & what a mess the oil we were using made inside our engines. Today I no longer race, but I own and use quite a few two cycles. I mix my Mobil 2 cycle synthetic oil, at 100 to 1. Now as clean as they run compared to the old oil and mixture rates I still understand that a 2 stroke uses new oil at every pop.

As you see there is no way that we can draw anything from the 2 cycle experience, when a 4 cycle uses the same oil day after day. All that study on oils was not wasted, I will never use an oil or additive or even a grease with Teflon or PTFE again. Do some reading and find out why DuPont would not let their name Teflon be used in automotive oils. This is why it is referred to as PTFE instead. We all get suckered once in awhile
 
  #8  
Old 05-22-02, 10:00 AM
Joe_F
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Thumbs up

Good point Marturo.

The trap most fall into is exactly what you said...extended drain intervals. However, water, acids and the rest of the contaminants attack synthetic oil the same way.

Changing the oil flushes out the junk so the new oil can do its job . That's why we change it and change it often .
 
  #9  
Old 05-22-02, 10:49 AM
Dan Meyer
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Oil change

From the tests that we have run in the lab and on actual engines (including work done with GM), the 3000 mile oil drain interval is excessive. But with a quart of oil costing a buck, that isn't a big deal. Just don't go ballistic if you go beyond the 3000 miles before a change.
 
  #10  
Old 05-22-02, 10:59 AM
otter_
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fyi

I know this is off topic, but it's good food for thought:

Read recently in 02 GM owner's manual:

"Change engine oil and filter as directed by the GM Oil Life System[SIZE=1]tm[/SIZE] or 12 months, whichever occurs first." The system does NOT analyze the oil to tell you when it's ready to be changed, it uses an algorythm based on RPM's, run time, load, ambient temp, coolant temp, etc.

This assumes that GF-3 grade oil is being used by whomever is servicing the vehicle.

I see trouble over the horizon.
 
  #11  
Old 05-22-02, 07:08 PM
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A few things to consider.

I know that oil made today is far better than we had just 15 years ago & can go longer than 3000 miles.

When we factor in that not every engine has a K&N air filter and K&N valve cover breathers. I use this type of filter because it is dust and grit that also gets into our engines we must consider.

I even put a light coat of high temp grease on my oil fill cap gasket, all in an atempt to keep grit out. So for the vast majority who do not go for these extra protections. I would think that 3,000 miles between oil changes would be a safe inexpensive part of their maintenance program.

Marturo
 
  #12  
Old 05-22-02, 09:38 PM
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Hey Marturo....I read a study that showed K&N filters were actually less effective at removing particles from the air than a good pleated paper element. It allowed more airflow (CFM), but didn't filter down to the smaller micron sizes that paper elements do. It was an online study, but I can't remember where I found it. I know this is getting away from topic, lol.
 
  #13  
Old 05-23-02, 10:50 AM
Dan Meyer
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Oil Change

Otter,
Your comment regarding the GM oil change light is exactly what I was involved in when I mentioned the testing that was done. I worked with S. Swartz and D. Smolinski at GM's research center who developed the system. It was this research and my own research (over the past 35 years) that prompted me to make the statement regarding the changing of oil every 3000 miles.
 
  #14  
Old 05-23-02, 11:53 AM
Joe_F
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Oil change intervals: Depends on the driving. Bottom line.

Most people DO drive in the severe category and don't know it. Short trips, idling, etc. That's severe service. The oil never has a chance to burn away the water and junk in the oil.

That being said, the safest way to know what to do is to read the owner's manual and see how your driving compares to the qualifications in the schedule.

Do that and you'll be fine on an engine that is properly designed.
 
  #15  
Old 05-23-02, 01:15 PM
otter_
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To Dan Mayer:

Re: research

So you're saying trust the system. I guess it will cause fits in service departments that want to see their clients every three months.

What I find disquieting is that last year the owners' manuals stated that if you drive under "severe" opeating conditions, ignore the oil life monitor and change every 3 mos. This year the exclusion has been dropped. What gives?
 
  #16  
Old 05-23-02, 07:11 PM
Joe_F
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Thumbs down

I wouldn't want to buy a car with an oil life monitor.

Think about it. The car comes off of lease. You buy it. It may not have seen an oil change in 20,000 miles because the light said it was ok.

I work with a guy whose brother had an Audi on lease. Went over the mileage, never changed the oil. Eeek.

I'll stick to 3k/3 months and the owner's manual, thank you.
 
  #17  
Old 05-23-02, 10:36 PM
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Common ground

Cheese tells me that the K&N filter may not be as good as some paper filters. Ok I know Cheese will share that with us if he finds it.

For me Just the fact that cheese told me he saw it, is worth going after it. So now lets say the K&N Air Filters were not almost oil bath air filters, like I thought they were. This now could be even more reason to change at 3K. More and smaller pieces of grit getting in through my ineffective Air filters.

I don't know what this light test is. So I am going to say that when I ran a paper Air filter I did not put a protective layer of grease top and bottom. I used the old chrome oiled foam shrinking wonders, for VC breathers.

What are we really talking about here & now?
1. How many miles will oil go, before the petrolem and or the additives wear out.
2. How many miles should we go with combustion by-products & grit from the air coming in any where it can.

We are in an endless loop If we can't find some common ground.

It may seem unimportant in this forum, but I feel better mentaly by changing my oil at 3K. The old oil even feels & smells different than the new oil. It could be all in my mind, & not a bit used up for another 3K. I would like to hear balance in this forum this time & maybe, we can walk away with something real.

Dan, can you tell me how long I should run 6 quarts of 20W50 Castrol with a 2 quart Wix oil filter? I really would like to know if I am throwing a good oil & a good filter away 3Ks before I begin to even start to wear my engine. You don't have to be exact however If it turns out that I have paid $84.00 + $56.00 for a 6" K&N Filter and matching top in order to get more grit in my engine than a $6.00 papper filter, well I would like a little truth for a change. Am I wasting money and resources for a wives tale on true oil change intervals?

Marturo
 
  #18  
Old 05-23-02, 11:46 PM
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Marturo....I'll see if i can track it down for you. I believe I found it on this forum....someone posted the link in their thread. It's been awhile. I will say that just because it's on the net doesn't mean it's true, as you know. I was under the impression that K&N filters were superior also, until I read the report.
 
  #19  
Old 05-24-02, 05:39 AM
Joe_F
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My personal opinion is that a K&N is a waste of money. I surely don't want more dirt into my engine.

I'll use a 5 dollar Delco filter and change it every year or so when required. Easy, efficient and done. GM would have jumped on this bandwagon long ago with their Performance Parts division if this really had much merit in the long haul .
 
  #20  
Old 05-24-02, 08:29 AM
Dan Meyer
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Oil change

Marturo,
I can't tell you when you should change your oil. You did make a good point that if it makes you feel good-change your oil every 3000 miles.
The only way to determine when to change oil is to do a periodic full lab analysis on the oil. We do it every 1000 miles for checks on car and truck fleets. When the oil is shown to be "out of spec" then we recommend changing the oil at that interval (or back off 500 -800 miles to be on the safe side).
Regarding GM's Oil Life System I was involved with. To date, oil testing has been done on over 2 million test miles under every possible driving condition. Drain intervals with the Oil Life system is between 10, 000 and 15,000 miles!!! My own research bears this out with fleet testing. In Europe, the drain intervals are 15,000 miles.
I change my own oil every 5000 miles. In as much as I work in the Petroleum business, I do my own lab testing for free. I even get my oil for free, so cost isn't a factor.
As far as oil filters, you may have noticed that the filters on cars are getting smaller and smaller. The ONLY purpose the oil filter serves is to catch the nuts and bolts that fall off the bearings so they don't rattle around in the oil pan.
 
  #21  
Old 05-24-02, 09:53 AM
Joe_F
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Considering we don't have our own lab equipment to do that we rely on knowledge and what's tried and true to get it right .

I remember my dad talking to a GM rep some years back that agreed with my Dad's thinking on the 3k/3 month mark. Most people drive in the severe category and don't even know it.

I still wouldn't trust an oil life monitor to tell me when to change my oil.

Europeans do different types of driving (Autobahn for example) so the oil has a chance to burn out all the water and other junk in it. That being said, oil in Europe is significantly more than it is here. I'm all the advocate for conserving oil and doing what's prudent and practical to do the right thing .

I believe if you keep a good running car going for a long time with a little TLC you will keep it out of the junkyard and subsequently out of the waste disposal system .

Dan: Can you elaborate on the last statement about the purpose of the oil filter?
 
  #22  
Old 05-24-02, 10:51 AM
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Smile Just more ????

Dan said:
As far as oil filters, you may have noticed that the filters on cars are getting smaller and smaller. The ONLY purpose the oil filter serves is to catch the nuts and bolts that fall off the bearings so they don't rattle around in the oil pan.

Yes as a mater of fact I was concerned when I saw a half pint oil filter on th 81 Bonnie with over 200,000 miles and still going strong.

Ok I will dump the K&N I mean sell of course. I have 2 Oil bath air filters for the 65 and back 345 International engines found in School buses and Dump trucks. They will fit Holley and Quadrajet carbs using the wing nut with gasket hold down.

My son has been running an Oil bath on his 650 cfm squarebore for a year now. I did not think it would work because of the flow required. The oil bath is quieter and when he has a load in the truck and the 4 barrels open it does not suck up all the oil in this filter & oil his plugs.

The part about the oil filters has me concerned. We have oil that keeps particals in supension. This filter says it will catch down to 5 microns Amsoil has a secondary overflow filter that goes down to 1 micron. All I assume to rid our oil of something as small as 1 micron.

We even now have filters that have synthetic media to trap smaller and yet allow good flow for people like me with Hi volume Hi Pressure oil pumps. It kind of makes me wonder if I should not move my oil slower with less pressure. To allow more time in the filter to be cleaned.

It is either a great sales ploy or a great filter. If you look around at all the K&N filters that just came on board for new cars & old using their own air filter housing. It seems, this is a company on the move up. So after everyone is convienced that a pleated oiled air filter is better than a dry paper one only now do we find out different. If given a choice of paper, I would chose Wix over Delco, it has been proven better in more than one test. Also as cheese pointed you can't believe everything you read untill you see it more than once.

Delco makes points also but from using Delco, Accel & Mallory lasts 3 times longer. Yes I still use points

Now I know none of us fall for Hoaxes on the internet. So why do I have a shortcut to Urban ledgends on my desk top?

I can see that like Chevy vs. Ford we are going to allow ourselves to be swayed by what we learned as we grew up.
So I think it is good to have these discussions if nothing more than to get all sides of the never ending question (When should I change my, what kind of oil should I use)

I think I will write a few air filter Mfrs & see about the K&N. Most of us have a place to work on our cars but not a lab like Dan does. I won't throw what Dan tells me out. I will keep learning and sometimes you come accross the truth about things like Teflon & why not to use products with it in your engine.

But why the Oil filter is getting less important. I remember a question over at cheeses forum about choosing a small engine based on one had a filter & one did not. It seems the one with filter won the nod. How can that not be the same on an automotive engine also?
Lost in Cyber space as allways, Marturo
 
  #23  
Old 05-24-02, 05:56 PM
Dan Meyer
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My oil filter remark

Joe, when it comes to oil, I can see that you already have your mind made up so I won't try and confuse you with the facts.

My remark with the oil filter was facetious. The oil is formulated to keep some contaminants in suspension and neutralize others. If you have a filter that will take out all the contaminants, such as "earth" filters, then you're also going to filter out the additives in the oil. Oil filters really aren't very useful in cleaning up the oil. And the oil is very effective by itself in keeping the engine clean and protected.
 
  #24  
Old 05-24-02, 07:00 PM
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In the begining the question was.

How it all started
First question: I'm thinking about changing to synthetic oil in my '96 Corsica. Does synthetic make a significant difference in the life of your engine? Do I change the oil every 3000 mi. as with regular oil? Is there anything else I should know before I change over?


2nd train of thought: Oil filters really aren't very useful in cleaning up the oil. And the oil is very effective by itself in keeping the engine clean and protected.

3rd conclusion : Yes gowiththeflow do change over to synthetic oil & change it every 5 thousand miles.

If I go with Mobil One synthetic 15W50 and change it every 5K, I should get better protection and longer oil life & damn near the same cost for an oil change.

Dan do you agree that if I follow this oil change shedule I should incur no more wear than before? That would be compared to using Castrol 20W50 changed at 3K. Both would be with a 2 quart oil filter.

I remember the oil to gas ratios we ran back in the 70s & today because of Mobil 2 cycle Synthetic, I run all 2 cycles at 100 to 1. I have good runing clean 2 cycle engines. So I would be a bit daft to believe that only 2 cycle oil has improved.

What do you all think, and please don't let what we learned 20 years + ago cloud your thinking. Would you use Synthetic oil for 5K? Remember that was the first question of this forum.
Marturo
 
  #25  
Old 05-24-02, 07:57 PM
otter_
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I'm with Dan

on this one. He's not the first person from within the industry say that for most 3k is excessive. The research he makes reference to backs up his claim and I feel more comfortable advising my clients to "trust the light".

Based on what's being said I'd run to 5 with REGULAR oil unless I'm running a high load/ high rpm application.

One more point to make, and this is for Dan...the tech on the monitor is impressive (I WAS fishing with the oil life post): I know that under more severe conditions such as arctic environments the system warns the operator of oil change time as early as 2500 km.
 
  #26  
Old 05-25-02, 06:10 AM
Joe_F
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And the fact remains, READ THE OWNER'S MANUAL and heed their advice . They might say 3k. They might say 5k. Depends on your driving.

Under most conditions, the OE states the tranny fluid can go 100k before needing a change. However, experience tells us that every 25k with a filter keeps you out of the tranny shop at 100k. You can't expect oil to slosh around with junk in it for a long time .

Depending on my driving, I look at the book and then decide what's right for me. If I get under the car every 3 months, I also have a chance to spot other problems, leaks, troubles and possible breakdowns before they happen.

Dan: You won't change the facts for me, because the facts in my owner's manual say I drive severely (city traffic, idling, short trips, etc). dictating service as such. The oil of today is far superior to what was around in 1984 when my 84 Olds was made. We've already got an improvement right there.

If the oil filter wasn't that important in theory, it wouldn't be recommended to be changed every time. You won't shower without soap (as the soap breaks up the dirt), so I don't change my oil without doing the filter too. The last thing the manufacturers want to do is add cost, so there is more than small benefit to having one there.

Not trying to be a smartass, but following or exceeding (in the sense of doing it before) the manufacturer's intervals will on the whole net you a long running engine without any trouble in the motor. This is a very interesting discussion!

TowGuy, myself and others here drive in severe conditions and that dictates 3k changes. My friend who's coming over in a little while for us to service his 1991 Shadow goes a bit more as he does highway driving on his commute without any real traffic. 143K on that car and no problems whatsoever. Different driving style dictate different maintenance requirements...the owner's books stipulate this clearly.

The fact is, as Marturo correctly brought us back to the original question, is that synthetic oil in most applications doesn't net a whole lot of benefit that people can see. If I'm running a high dollar engine, than maybe yes. For an everyday cruiser, being regular with your upkeep will keep you running a long time.

You could spend 5 bucks a quart on Mobil 1 for a Corsica like this and in the end, you probably have just as good as car if you did regular upkeep, but it cost you more. The trap is to extend the intervals and keep doing so under the false guise that it is Ok. In turn other things are also forgotten about.

An oil change for me is 6 bucks with oil filter and grease. . If I went to synthetic, I'd have beat up oil in the same time and my wallet would suffer...and I'm getting probably zero benefit in stopping wear and troubles on such an old car... the "damage" has been done.

Again, it depends on your driving, style, engine condition as to what schedule to follow. Even the oil bottles will say, "adhere to the manufacturer's drain intervals and check the owner's manual for the proper grade of oil required".

My .02 (and a lot more..lol)
 
  #27  
Old 05-25-02, 05:21 PM
Dan Meyer
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the drama continues....

Marturo,
There is no proof that spending extra for a synthetic is going to give you any additional benefits over conventional oils- with the exception that a synthetic is better for cold weather starting - try Alaska or the Artic.

Sure the oil companies are pushing synthetic. There's a lot more profit in synthetics. Just like Slick 50. A real rip off of NO value!!!

I have three cars each of which I pamper. I don't cut corners on maintenance. I do not use synthetic oils! I change oil around
5 000 + and the filter every other oil change.

You say you have a 2 quart filter. I assume that this is an add on. So this means that you have 2 extra quarts of oil than what the car came with. The more oil you have the more contaminates it will hold and the more additives are in place as they are depleted. And if you add a quart or more between oil changes, you are really replenishing the additives. It would appear that you certainly could extend your drain period. How much further, only lab testing can tell you. There are labs around who do oil testing. A lab analysis would run around $100.
A question. Why are you using 20W-50?? Do you live in the deep south where it's hot year around or towing a heavy trailer?
 
  #28  
Old 05-25-02, 06:48 PM
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20W50

Why am I using 20 W 50? Well I am using a 1974 350 engine that went 150,000 miles then a complete overhaul with blue printing and balencing. I got just a little carried away with the roller cam & rockers. plus lol.

But first a little history. for the entire 150,000 miles it was Castrol 30# with 1 quart of Marvel Mystery in cool weather and 1 quart of Hi-Tach in hot weather. Changed every 2,500 miles. I got my oil and filters plus additives in shop at cost.

Fast foward to this 350s new life as a hot engine. With 30# only I had 30 psi at idle & 45psi running. With just 20W50 I got 45 psi at idle and 60 psi while running.

So I thought we wanted more pressure at different rpms. I have a 411 rear end ratio with 4K lbs of 1969 C/10. I was going through my second childhood. This engine is a power house but not all the time.

What weight oil do you think I should be using? Should I use one for winter avrage low is in the 30s and highs in summer in the 80s. Altitudes are 2,700 to 5,200 above sea level.

Marturo
 
  #29  
Old 05-26-02, 12:41 AM
sciguyjim
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using heavy weight oil

Marturo,

I read recently that if you want to go to a higher wt oil, it's recommended that you only go up one step from what the owner's manual suggests using. Going up 2 steps is almost always too much. The higher viscosity reduces HP and since the engine is working harder to move its parts, the engine temp can go up. It's possible too that oil too thick can cause more wear than a thinner oil. I live where summer temps can get around 100 F and 5w30 is recommended for my car ('89 T/A). One summer I tried a mix of about 50/50 Mobil 1 5w30 and 15w50. It made a noticable change in performance. When I took my foot off the gas the car slowed down faster, at first I didn't know why, but it was the thicker oil. My MPG would have dropped too.

Also, I read that higher oil pressure is not the same as oil flow. A thinner oil, showing less pressure will flow easier and this is what we need for the oil to wash particulates off the moving parts.

So, 30 wt should be ok unless you have some slop in this old engine, then you can go to 40 wt. I hope this helps, Sciguyjim.

You shouldn't have to increase the first # (ie 5 in 5w30). You still want the oil to pump easily in cold weather, even if it only gets into the 30's.
 
  #30  
Old 05-26-02, 12:57 AM
sciguyjim
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Question What about a car that sits for days?

Hi guys, I'm looking for your opions here. I recently read how if a car sits for several days there is less residual oil remaining on it's parts so when it is started there is more metal to metal contact than if the car is driven every day. In other words, the cold starts are worse than usual. I'm afraid this might be happening to me. I have magnets on the oil filter to grab some of the metal particles as they pass and I've always seen more microscopic particles than I thought there should be, but I've never tried this on any other car so I don't know if my amounts are typical.

I just looked at my mileage over the last 2 years and I'm only driving about 2550 mi/yr. That's about 50 mi/week. The car is used 1 to 2 times per week and as little as possible in the winter.

Is there anything special any of you would do to improve the lubricant layer remaining on the walls so that cold starts aren't so abrasive? The car is an '89 T/A, 305 MPFI, with almost 58000 miles, and I use Mobil 1 5w30 yearround. I had the idea to put the accel to the floor during starting so that oil got a chance to pump for a few seconds before the engine started, but I was talked out of it by some people. The main thing is that they felt the oil wouldn't get very far at the slow RPMs provided with the starter so it wasn't really worth cranking the starter for the extra time. I look forward to your comments, thanks.
 
  #31  
Old 05-26-02, 08:29 AM
Joe_F
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Thumbs up

I think we answered that one for ya a couple of posts ago in another post.....

Either a preluber if you feel is necessary or just continue to use your Mobil 1, good maintenance and you should be fine...even when the car sits. My opinion is that your car doesn't sit nearly long enough to cause any concern.

Chevy V8's of this vintage blow valve stem seals and generally get some oil related troubles around 100k or so, problems with oiling are likely to come here first than with the bottom end.

I use 10W30 in all my cars but the 84 Olds and the 79 T/A.

I use 10W40 in the 84 Olds because it is older with 143k on the engine. The 79 uses 10W40 because it is shown as one of the recommended oils for the car in the owner's manual.
 
  #32  
Old 05-26-02, 09:46 AM
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Smile Pre oiling before start.

Sciguyjim
Thanks for the info on the oil weights, I have a lot of thinking ahead. You asked about the cold start wear & this is where I have allways heard is the danger time also.

My 74 350 totaly rebuilt with teflon seals on cut down bosses for maximum oil control unlike the o-ring or umbrella seals of the past. I do now see that some while back GM started cuting down the bosses and puting the clamp on valve seals for better oil control.

I have allways pre-pumped my chevy V8s. If you start a GM V8 that has sat let's say for 3 days they click untill the oil gets up to the lifters. Not to long but it says that the lifters are not pumped up.

What I have been doing for years is, just crank the engine until the gauge starts to go up or the oil light goes out. Might be 20 seconds. Then start it like you do, I pull the choke out 3/4 pump twice and start. I have tried this enough both ways to say I won't start without prelubing. If it pumps up the lifters it must get the oil on up into the engine also.

The ones who say the starter does not turn the engine fast enough to prime the engine, must answer this. How does just the starter pump up the lifters so they don't clack & how does the oil pressure go to 50 psi on a gauge up in my cab, when I crank for just 20 seconds.

You see I am a product of non multi weight oil. I learned that harleys took 60 or 70 # oil and if you had a muscle car it was the pressure that kept the metal to metal from happening because it was pressurized by a layer of oil.

So until I learned about polimer chains and how they formed chains, I did not believe you could get a 20# oil act like a 50 # oil.

In years past we chose an oil by what that weight oil would be when it reached running temps. So if you had a hot 396 in a 1969 Chevelle you might want to run 40 or 50 # oil depending on how you drove. 30# would thin out to much and result in galing of crank and cam bearings due to a lack of oil pressure holding the metal parts away from each other.

I am waiting to hear from Dan on the 20W50 that I use. A lot of the new cars use very tight clearences. However when I had the clearences cut for my 350 V8 I had them cut on the large side so when it got hotter than a stock 350 V8 I would not have problems with clearences being too tight.

So when the 30# oil I had used in the past in my stock engine showed lower pressure than the 20W50 in a HI-PO engine I thought it was what I wanted seeing that I put a Hi-Volume Hi-Pressure oil pump into the picture. You have read about burst strenth on different oil filter cans. Racing cars run very hi oil pressure and flow, so with a 350 with a cam that is sweet at 4,800 to 5,600 rpm I thought by using an oil with less pressure was going to hurt not help.

Marturo
 
  #33  
Old 05-26-02, 10:49 AM
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Here is one to argue over. My 92 Z28 has had mobil 1 in it since the first oil change. 68,000 miles later changing the oil at 6,000-8,000 intervals in Arizona should be a pretty good test. I just had the car dyno'ed and it pulled 223 hp with 318 ft. lbs. of torque. The motor is completely stock. The dyno shop removed the intake to repair a small coolant leak and said that the motor was one of the cleanest they had seen. The dyno results were the highest they had seen off of a L98 stock motor. The closest they had seen was 198 hp. I know some of you are thinking that 245 should be the stock hp, but the true rear wheel hp from the factory is the 195 range. Is it the oil? Probably not completely, but I feel it was worth the extra money.
 
  #34  
Old 05-26-02, 11:11 AM
sciguyjim
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Joe & Marturo,

Thanks for the very helpful info. Yes, I was the one in another post who was asking about preoiling. Like I said, I was talked out of it, but since then I read that having the car sit for some days between runs makes the cold starts worse. That, my low yearly mileage, and the metal I find in my oil filter, made me begin to wonder again if there was anything extra I could be doing. I would have guessed that cranking the engine for 20 sec would be too much for the battery and starter but I'll give it a try and watch my oil pressure. Thanks again for your opinions.
 
  #35  
Old 05-26-02, 02:07 PM
Dan Meyer
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20W-50

Let me give you some oil basics:
The advantage to a higher viscosity oil is that it will give better hydro dynamic boundry lubrication - in other words it will give a better "cushion" between moving parts. The disadvantage is that it will create more friction (more power to circulate it) and reduce gas mileage. Harder winter starting.
A lower viscosity oil takes less power to circulate it and therefore, gives better gas mileage. That's why the auto mfgr. recommend lower vis oils in order to meet CAFE rules. It also gives easier starting in the cold weather.
High temperatures lower the viscosity of oil and therefore reduces this "cushion" of protection. Higher loads on the engine (like pulling a trailer) require a heavier oil.
A multi-viscosity oil is a "straight" weight oil with a Viscosity Index (VI) improver in it (polymethacrylate).
For example, a 10W-30 is a 20W with a VI additive. A 20W-50 is a 45W with VI additive.
The greater the spread between the numbers the more VI improver it takes to create this spread.
As the oil is used, the VI additive "shears" out and the oil reverts back to its original viscosity. In the case of a 10W-30 it reverts back to a 20W.
The first number is the viscosity the oil is equal to during the Cold Cranking Simulator test at -18C. So a 10W-30 would be the same viscosity as a straight 10W would be.
The second number is the viscosity the oil would be at 100C.
One last point, NO oil additive (slick 50, Rislone, STP, Marvel Mystery oIl , ETC) has EVER been proven to be anything other than a waste of money. Anyone who claims they can 'TELL' their car runs better using these "snake oils" or different oils should get a job with an oil company who spends millions of dollars buying dynamometers just to test these things.
 
  #36  
Old 05-26-02, 06:25 PM
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We are going to break some recors soon.

Thanks Dan,

I can see oil is not as basic as I had once thought. The 20-50 being a 45# seems that it might be too heavy for cooler weather.

Yet 10-30 may be a better choice for cooler weather it might not be enough for summer when using the truck to haul loads.

See I thought that the 20-50 did it's thing like this. When cold it stayed a 20# for easy starting & when it heated up it got thicker providing more protection eg: higher oil pressure to protect against metal to metal due to a poor cushion.

I have seen oil lately that was 15-40. Is this a different mixture looking for an all season oil? If not. What weight should I try for winter? Also because I have built in more power & heat into my 350 engine. Would 20-50 not be the best choice for hot weather.

I am in total aggrement with you on snake oil additives like those with soild particals PTFE (Teflon) I have read enouth to prove to me that it is oil and only oil I need for lubrication.

This subject of oil is the biggest area of smoke & mirrors in all the cons of DIY auto repair. You have seen the torture tests they put those engines through in the infomercials on Sat & Sun mornings. As big as the snake oil industry is, I don't think any real atempt will be made to make them prove all this bull.
PS: http://www.motoroilbible.com/ I just found this & wanted to share it will all of you. Exposing the 3K oil change Myth. Now we do want to get at the truth even if that means changing what we have believed all our lives. To believe things don't change is to stop learning. That is totaly oppsite of what a DIYer is all about.

Marturo
 

Last edited by marturo; 05-26-02 at 07:20 PM.
  #37  
Old 05-26-02, 06:29 PM
sciguyjim
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Question

Dan,

I agree with most of what you said except for one part:

"... So a 10W-30 would be the same viscosity as a straight 10W would be. The second number is the viscosity the oil would be at 100C. "

The "30" is the weight (viscosity) of the oil at 100C, but the "10W" does not mean the oil is equivalent to 10 weight at low temps. The "W" stands for winter, not weight. Like all other liquids, oil thickens when cold so at low temps the oil will not be like a thin 10 weight oil. The "10" cannot be treated like a viscosity rating, all it is good for is comparing with other oils and their "W" rating. So, you can say a 10W oil will pump easier than a 20W and harder than a 5W oil.

As far as additives go, don't the zinc and phosphorous anti wear additives help at metal to metal contact points? You won't be able to feel a difference from them being in the oil but the engine will. The reason we don't just dump more of these additives into the oil is because of possible cylinder deposits and cat convertor damage.

Do I have my facts correct?
 
  #38  
Old 05-26-02, 07:31 PM
otter_
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metal to metal

"As far as additives go, don't the zinc and phosphorous anti wear additives help at metal to metal contact points?"

Unless I have it totally wrong, all internally lubricated components of an internal combustion engine ride on a cushion of oil. There should be no metal to metal contact in these areas.
 
  #39  
Old 05-26-02, 08:56 PM
sciguyjim
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Ideally everything should be protected by a layer of oil but in the real world contact does occur, very often at microscopic points. The anti-wear additives do not prevent contact, but they do minimize damage by forming alloys with the metal. When contact does occur the temperature at the microscopic contact point can easily go up above the melting point of the metal. At this time the phosphorous forms an alloy with the metal which has different wear characteristics than the metal alone. Phosphorous is also used as a high pressure additive in gear oils and greases. As long as they stay in the motor oil they can't harm the cat convertor but when the oil is vaporized and burned they get burned too and then poison the catalyst.
 
  #40  
Old 05-27-02, 04:55 PM
Dan Meyer
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Straight facts

The zinc or Zinc dialkyldithiophospate is an EP additive. The Phosphorus is an anti-oxidant. Two different additives.
The 10w in 10W-30 IS THE VISCOSITY.
SAE 10 viscosity runs from Approx 120 SUS @100F to 175 SUS @ 100F.
Yes, oil thickens at lower temperatures. A 10W-30 and a 10W both will have the approx same viscosity at the same temp of -18C. A straight 30 and a 10W-30 will both have the same viscosity at 100C.
A 20W-50 will have the same viscosity at -18C as will a straight 20W. At 100C the 20W-50 will have the same viscosity as a straight 50 weight.
Forget the "W". thats an old carry over from the old 20W-20 days.
In the winter, the oil companies would blend on the low side of the 20 viscosity range and in the summer they would blend on the high side of the spec.
so Marturo, if you can start your car in the coldest of winter with your 20W-50 then yes, in the summer the 50 would give your engine better wear protection - of course, at the expense of lower gas mileage---can't have it all!!
 
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