3vze bad gas mileage

[Slowerthanyou]

Hey guys I know the 3vze gets bad gas mileage but I am only getting 175 miles per tank. It has new plugs, new O2 sensor, and the timing is at factory spec. Just finished doing the head gasket and it runs great just gets bad gas mileage. Also installed headers hoping to improve power and gas mileage. What could be the culprit of this bad gas mileage? I also do not drive it hard. Never put the pedal to the floor. It has 32x11.5 tires and is automatic. Purchased the truck with a blown head gasket so I can't tell you what it was getting gas mileage wise before the head gasket job. Thanks!

 

[94yotapj]

that is about what i get too. and i have 2wd 4runner. i average like 13mpg city and 16-17 hwy

 

[dogojoe96]

Your answer is in your own explanation (possibly), with the automatic trans and 32" tires gas mileage will suffer even if you are a grandpa driver. Unless you or the previous owner regeared the differentials that is probably the best mileage you could get

 

[Rodnic]

That is not good! We just got back from a camping trip which totaled 194 miles. The qauge was between a quarter and a half and it took 12.6 gallons to fill it. A little over 15mpg which is not too bad considering a good portion of that was in 4wd! I hope to do better but from what I have been hearing.....this may be as good as it gets. One of the worse Mpg robbers is low tire inflation and it is often overlooked. I haven't had my T4R very long but there are guys on this forum who have and I am sure they will have some possible ideas to help you out. Something is not right.

 

[Slowerthanyou]

I have read up on this subject as well before posting and it seems that there is people with the 3vze and auto trans getting between 250 and 320 miles in a full tank so mine getting 170 just seems like to much of a big deference to just say ahhh that seems right. Something has to be wrong here. The 1 inch larger tires shouldn't cause that much of a gas mileage change.

 

[flyinhawaiian01]

Those numbers are for a bone-stock truck in really good running order. You have 32's which will immediately kill your mileage-and yes, it will kill it by half, depending on where and how you drive!

Re-gear it to 4.88 with those 32's and you'll see your mileage come up a good amount.

Also, some of the 4 runners came with 225x75x15's, which is equal to a 28" tire, not a 31, not sure what yours came with but it should say in the door I believe.

In any case, 32's will still kill your mileage, especially if you live around a big city with hills and lots of starts/stops. And, unless you're only doing around 55mph on the highway, you'll still notice bad mileage.

Finally, did you take into consideration just how far off your speedo is with the oversized tires? Easy calculation, actually, if you're doing 55mph and your speedo is showing only 47mph (just arbitrary numbers here, have no idea what yours will be), that's a 6% difference, which means you need to add 6% onto your mileage. At 175 miles to a tank, and the above percentage, you're actually getting 185.5 miles. Not a big difference, but still a difference nonetheless.

 

[jgilk1]

I see a lot of math my truck came stock with 4.88 and 235/75-15 which is a 28" tall tire comparison wise i run 33/12.5-15 (318/72-15 metric) that a 14.4% off set in tire size


235/75R15 = 28.9X9.25R15
Diameter = 28.9"Width = 9.25"Wheel = 15"Sidewall = 6.94"Circumference = 90.7"Revs/Mile = 698.7

33X12.5R15 = 318/72R15
Diameter = 33"Width = 12.5"Wheel = 15"Sidewall = 9"Circumference = 103.6"Revs/Mile = 611.5


So the 33 12.5 does 87.2 revs per mile fewer or 0.8751 rev per mile ratio i average ~14mpg @ 200 miles this is less distance then tracking says i drive

with rev per mile ratio this is ~230miles at ~16mpg this better matches the distance i drive via gps and matches if i use this off set... When people ask what millege i get i lie and say 10...


But this math was used when i drove back from new mexico to washington and "distance was off only by ~6 miles vs using the odometer reading of ~190miles

that's a 6% difference, which means you need to add 6% onto your mileage. At 175 miles to a tank, and the above percentage, you're actually getting 185.5 miles. Not a big difference, but still a difference nonetheless.

This method works much the same for short distance calculations and seems more to give a gestimation havent done much in the way of long distance calculations with it...

But either method is a guess

 

[crazy gringo]

mine is an 88 with a 3.0 and a/t with 31/10.5/15 with no mods and Im getting in the city 12 miles to the gallon or 140 miles per tank average speed is 45 when i drive in the city high way is a little better. hell my 94 GMC Crewcab Duelly gets better mileage than my 4Runner, it is an under powered rolling brick and either you love your 4 Runner or its not the vehical for you

 

[jgilk1]

I guess i didnt post stats i drive exactly by gps 10 miles to work it takes 4 minutes longer to take the interstate as it does city streets (average 45mph) if i drive highway speeds (70mph) i lack enough power to maintain the use of overdrive half the time i average about 7-10 mpg highway or 98-140 miles per tank on the highway and like 4k rpm so i take city streets

There are 5 stop lights and 4 stop signes if i take city streets and like 12 stop lights if i take the interstate (go figure)

 

[airdreams1]

with a brand new motor, plugs, wires, cap, air cleaner, fuel filter, injectors, & on & on.... 31 x 10.5 15 tires Mine only got 200 miles per tank... (+mine has the largest tank. 18 gallons aprox.)
Everyone tried to tell me that was normal mpg for the 3.0.....
But I have to call BS!

 

[Slowerthanyou]

So I checked in the door and my stock tire size is 225/75. If I switch back to this tire size will this improve my gas mileage drastically? I would like to have 31x10.5 BF Goodrich all terrains because it gives the truck a much better look.

 

[penbergm]

it will give you probably drastically better mileage, actually & preceived.

Like everyone is saying, larger tires will lower your mpg AND it will throw off your speedo/odometer to give the appearance of even worse mpg's than actual.

With 33" tires my '86 was off by 15%. So if my odometer said I got 200 miles per tank, I was actually getting 230 miles. I confirmed this by using mile markers on a long highway trip. 100 miles on the mile markers was only 85 miles on my odometer.

Go with the smaller tires & hate your look or stay with larger tire & buy the happy meal.

I'm happy with the happy meal, 33's & a sexy 4cyl.

 

[wjmj]

The MPG in my brochure for my 1991 3.0 says 16/19. The 2 tanks I have gone through so far have been about 180 per tank and about 11 gal put in. It has 31" MT's and 2 bad front axles also. Head gaskets were replaced about 6 months ago. I was also hoping for more, but it is what it is. My 88 Honda Prelude gets 28 and it is advertised to get 26, then again it has the JDM motor, not the USDM motor, so it has more power, but that is an orange to our apple.

 

[xmindbender]

my first tank pulled 200 miles on 11 gal primarily in town and a few trips hauling approx. 600lbs of rock in back. no hwy mpg yet.

no lift, new 235/75r15 tires. 108k. I'm seldom in a hurry.

 

[Number_6]

FWIW, our company cars are Chevy Equinoxes, AWD and FWD. On an average work day, I can get 27 MPG at best with my AWD, when I drive a FWD from the lot I can get 32. The FWD is zippier too. So, getting power to all four wheels has its price. Weight and drag, I guess.

 

[HuntnRig]

So I’m reading this and seeing people complain about 12-15 mpg and 200+ miles per tank. I’m over here getting ~8 mpg and ~110 miles per tank. I have a 4inch lift with 33’s. Does this sound normal? And also what gears would one recommend for a 91 3.0 5 speed with the lift and 33’s?

 

[Eugene13]

That is pretty far from normal. You must have a really heavy right foot. and as far as gears id go with 4.88s but look around on google to see what other people are happy with

 

[HuntnRig]

Yes and no on the heavy foot. I don’t drive crazy but for instance, on the way to work in the morning, (slightly more uphill to work than home) to keep at 55 it’s either ~3800rpm in 3rd or ~2500rpm in 4th, and in 4th that’s pedal pretty much to the floor and you can still see the speedometer slowing going down. So I want to throw new gears at it to see if it helps the power and fuel mileage.

 

[Eugene13]

Im not experienced with the 3vz's and the transmissions hooked up to them as far as ratios. I wouldn't floor the truck at 2500 cause you're lugging the engine and 3800 is way too high to be cruising at for a while. Gears would make a huge difference, but its something you want to do a lot of research in and only want to do once because its so expensive. Get it done by a reputable shop to make sure they're set up perfectly. Spend the money to get it done right, once.

 

[T4rmtber]

I too am suffering from bad gas mileage. Just got my t4r and it came with 31’s. Should I have the gearing switched?