Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Gas Milage


wallyb's Avatar
Visiting Guest

Posts: n/a

01-20-04, 05:30 PM   #1  
wallyb
Gas Milage

I purchased a 98 chevy extended cab pickup with the 5.7 350 in it. I'm only getting about 13 mpg? Just wondering what everyone else is getting with similar vehicle? What, if anything, can I do it increase it. My mechanic said the plugs are good for 100,000 miles. Mine has 78,000 miles on it. I put in new air filter and fuel filter??? Any suggestions?

Thanks,

Matt

 
Sponsored Links
davo's Avatar
Member

Join Date: Apr 2002
Posts: 2,417

01-20-04, 05:51 PM   #2  
Brand new ones list 13mpg city 18 hwy so you have a truck and they are not fuel misers.Sorry is this your first truck?

 
redneck's Avatar
Visiting Guest

Posts: n/a

01-21-04, 06:33 AM   #3  
redneck
I got the same truck with about the same miles, and usually average 15mpg, mostly highway. I started to get a rough idle about 5k ago, and changed the plugs and wires, it runs like new again. Also, change fluids and filters regularly. Had the oil cooler lines replaced under warrenty at 17k (they are leaking again), replaced the idler arm and pitman arm at 60k, and for the past two years the intake manifold leaks a slight bit of coolent only during winter while sitting. That is it. Been a good truck, and I use it like a truck should be used. Sorry for the extra info, but it can't hurt.

 
wallyb's Avatar
Visiting Guest

Posts: n/a

01-21-04, 07:23 PM   #4  
wallyb
Nope, I've had a couple others, not quite as nice...LOL...but I talk to others with similar trucks and get 17 or 18 mpg. I travel highway mostly, so I guess I was looking to get more than the 13 I'm currently getting?? Would you bother changing plugs and wires if the check engine doesn't detect anything wrong?? I was told the plugs are good for 100K?

Thanks,

Matt

 
carguyinva's Avatar
Member

Join Date: Nov 2003
Posts: 1,147
VA

01-22-04, 05:10 AM   #5  
dumb questions...

...is it going into overdrive? is the convertor clutch locking up? have you checked the air in the tires and how are they wearing? a new set of plugs won't hurt...but may not give you all that you want mileage wise tho. did your mechanic check the system for codes? is the exhaust system original?


just a few questions to spur some more thought...

 
redneck's Avatar
Visiting Guest

Posts: n/a

01-22-04, 01:10 PM   #6  
redneck
What kind of rpms are you pulling at say 65mph? should be less than 2000 if lock up is working. stock tire size? I did notice a slight drop in power and mpg when I went to 285 tires.

 
wallyb's Avatar
Visiting Guest

Posts: n/a

01-25-04, 09:13 AM   #7  
wallyb
When I'm at speeds of 75, my rpm is about 2000. I did check tire pressure, they were about 32 psi, so I increased them to about 40 psi. Didn't really do much for my mpg. I have the correct size tires on it- 245/75/16. My exhaust is stock. My brake pads are needing repair, it seems like there is resistence coming from them??? Would putting a tonnue cover on it help it any?? I took the k & n filter out of it but it didn't change anything

Oh well, thanks guys for trying to help!!

Matt

 
Search this Thread