Hello!

I just bought a 1997 Nissan Pathfinder. Now, I do realize this is an SUV, and they are not gas savers. I asked the salesman about expected mileage, and was told to look for mid-high teens in town, and high teens to low 20s on highway. I am getting 12. (12.2 to 12.7 to be exact, with about 50/50 city/highway driving). I have checked online, and it looks like I should be getting much better than that according to other pathfinder owner's claims. It is running exceptionally well, but here are some things that I'm sure are cutting the efficiency down:

It has wide all terrain tires on it...31 X 10.50 R 15 LT
It has a large chrome brush guard across the front
It has 4WD

It does have dark tinted windows, and it's white, so AC doesn't run as much.
It does have OD.

I like the looks of it, but I'd rather have some MPGs. I am thinking the tires are the main culprit. Is this correct? How much do you think these tires might be affecting my economy? If it's minimal, I'll live with it, but I really want to get the average economy out of this thing.

It came with a K&N air filter (which I'm not convinced is the best thing, but it's on there).

I also considered buying a "Tornado" type intake insert that claims better performance, mileage, and less emmissions. Anyone have experience with one? I've heard good things, but I'm skeptical of a gimmik too.

I also plan to use synthetic oil in the engine and the transfer case and differentials if this would help. Can you use synthetic in a limited slip differential?

I'd like to keep the ride, and if I could bump my fuel economy up about 5 mpg, it would be in the range of other SUVs, and I'd feel much better about it. The way it is now, I feel like I could trade it for a 4 runner or most any other suv and get better mileage.

Sorry for the lengthy post. Any helpful input would be greatly appreciated.

 

If this tire is larger than OEM, you may be getting better mileae than you think. An oversized tire allows the drivetrain to rotate fewer times over the priod of a mile. Unless the speedo was corrected, this would result in the speedo reading lower than actual and you registering fewer miles than actually travelled. The size of them alone will cause a decrease in milieage due to a higher rolling resistance as well causing an true mileage decrease.

always a negative on mileage but with some models it is not a huge negative.

Pop mechanics or Pop science did a thing on this type of device (including the tornado). No improvement recorded.
I do in my Ford P.U. but it is original equipment. You need to talk with a dealer to make sure it is compatible with the seals and if the old needs to be flushed or mixing is ok. I have to use a friction modifier because it is limited slip. Mine is a ford product I would suggest asking the dealer here as well.
Sorry I can't help much more than that. Others probably will toss in some advice as well.

 

Get a good tune up with good quality park plugs, K&N Intakes are really good just make sure filter is new or you can buy a kit to wash it and clean it, then re-oil it using not too much oil on it.
Tires are not a factor IMO in either way it would be minimal gain or loss.
Syntetic oil is a good idea but more to portect drivetrain than to improve mpg.
Ask yourself how much are you going to actually save by trading it ? just to get 2 or 3 more miles per gallon ? consider new license plates, down payment, insurance etc.
Nobody gets the actual mpg EPA estimates says they should be getting so don't worry too much, and please stop counting the miles it'll stress yourself out

 

I ran a full tank through my 96 Pathfiner (164,000 mi) some a/c on, round town to 75 on the freeway. Averaged 14 mpg. I was impressed.

Jay