gas milage dilemma

[qx4hart]

hello all - i have a small dilemma that i just can't figure out...i own an 01 qx4 and about 5 months ago i switched to premium grade gas b/c i wanted the truck to run better. nothing was wrong with it, i was just under the assumption that with a higher grade of octane i would get better gas milage; but, i've been getting worse gas milage. i currently average 13-14 mpg of city driving and 16 highway driving. i've changed the oil, oil filter, air filter, check tire pressure, and checked for codes but all seems fine.

what else could i be missing that would give me worse gas milage with a higher grade of octane in the tank????

anyone have any advise?

[KoukiS14]

But it still performs the same with 87 octane? higher grade of fuel won't give you better mileage, actually shouldn't affect it. I'd only recommend it if you're running forced induction of any kind, have a super high compression, or are experiencing pinging. Regular running around in town doesn't really call for it.

I know the VQ recommends premium, but we have several running low grade in their VQ R50s.

Welcome to NICO!!

[timmack]

switch back to 87 for a few tankfulls and see if the mileage goes back up.

[02QX4ME]

I tried on a few different cars between regular and premium gas. There has been no difference at all to me. If there IS an MPG difference, it could be just a tiny compared to my driving style, road conditions, etc. I always use regular with no problem so far.

[timmack]

i heard of older spark plugs not liking a switch in octane-fouled em up pretty bad.

[qx4hart]

still performs the same with 87 octane, no difference except for in the milage. i'm gonna switch back to 87 and see if it goes back up to what i was originally receiving.

[Buzzman]

FYI, there was a good discussion/thread on this subject a few months ago.Lots of good information on octane and what it really means, etc. Might be worthwhile going back and checking it out.Personally, I run regular gas with no noticeable differences in performance or mileage. The extra cost of premium is not worth it.

[pathfinder_se_black]

sugestion; when have your spark plugs and wires been changed? or have you tried some good fuel injection cleaners?





these are very good from my experience. i would use the bg44k but it is starting to get hard to find in my area. the lucas racing injector cleaner is also very good. i use it every other gas tank and it is cheaper by the oz when you buy it bigger. hope that helps

[qx4hart]

ya, very good information was posted & i went back and read and it was very informative. but thanks to all who replied to my question eventho it was discussed many times b4.

[QUOTE=pathfinder_se_black]sugestion; when have your spark plugs and wires been changed? or have you tried some good fuel injection cleaners?

now that i think about it..i'm not too sure when the spark plugs and wires were changed. i've had the truck for about 9 months now and the dealership told me that the maintenance was up to date. but, i guess it would be helpful to know when the plugs and wires were replaced or if they haven't ever been replaced.

[97pathLE]

i had poor milage on my 97 path and i changed the fuel filter and i got anonthe 100km a tank almost immedialty after....

[stevebaz]

replace the air filter and clean the maf sensor.

[qx4hart]

i replace the air filter everytime I change the oil. 87 has been giving me better milage now since i've changed back. 93 no more! it's a waste.

[cmkelly]

You don't have spark plug wires on your truck, only coil packs. I tried to replace mine a while ago and couldn't find any after market plug wires for my 01 Pathy....you know why?......they don't exsist!

[stellanti]

Hey,

Im a noob and found this thread. I have an 01 Pathfinder and gas milage is pretty bad (13.5mpg) and that is mostly highway. I do have ski racks on and im wondering if that has a big affect on gas milage. My tires are good, just had spark plugs, air filter, fuel filter, all fluids (transmission, transfer case, both differentials) replaced. It has 50K and runs great, but the gas milage is bad..... what is up?

Any help is appreciated. Thanks

[SnowSurfLax]

Lose the ski rack and you should shoot up .5 - 1.5 mpg depending on how you drive.

It's creating drag and making your engine work harder, hence the lowered gas mileage.

[stellanti]

I figured that was a problem, but I cannot lose the rack. Definitely need that for the winter.

Anyway, I am thinking it has to do with "winter gas." I remember reading somewhere that winter gas has more additives (to keep from freezing, colder temps, etc) than summer gas. Is this true?

[SnowSurfLax]

Yeah, winter makes your car work harder for various reasons. You'll always have slightly worse gas mileage in cold weather. You just notice it because our vehicles already suck as it is.