3.4 5spd MPG 31's vs 32's

[Huhwhye]

I have seen many MPG figures from 3.4/auto rigs. I want to know how the 5speed does with different tire and gear combos. I am considering a few things and what to know what the effect will be on economy.

I don't want any numbers from automatics.

Because of the different overdrive ratio with the 5speed I run about 500 rpm higher than an auto. Comparing my 00 to my friend Taco with an auto. This puts me at 3000 rpm at 80mph.

Auto ratios
2.804 1st
.705 OD

Manual ratios
3.83 1st
.838 OD

If I go to a 32" vs stock 31" tire what will be the effect? This is the biggest tire I want to run on this vehicle. I know autos can take a big hit with stock gears. How to the manual trucks do?

What about a gear change? from stock 4.10 to 4.30 or even 4.56 with 32" tire. What will be the effect of that?

5speed guys tout their excellent mileage, and I want to keep mine.

[KliersLC]

I had 235 75 15s on my t100 stock, and I ran 305 70 16s on it with no gear change. Your mileage will really depend on your usage and driving style. I got 22 on the freeway with the 305s, but only 15 or so in town. With the 235s I got about 20 on the freeway and 17 in town.....Driving like a grandma...

You probably won't notice the difference, and unless you do speedo correction or gps calibration, you won't know the actual mileage you are getting.

[Huhwhye]

Nobody?

[Jetboy]

Make sure you compare miles to miles here, not odometer reading to odometer reading. A 32 may show a reduction of 1mpg, but in reality you are travleing further per odometer mile, so you may increase mileage. I think its a common mistake in these discussions. That tire difference should need around a 3% correction, So someone getting 22mpg based on the odometer with 32's in reality is similar to getting 22.7mpg on 31 as you would cover the same actual distance on a gallon of gas.

[Happy Trails]

I have a set of BFG AT 32's on my Tacoma presently. I think this is the perfect size. I have seen no
difference in performance. I'm getting 22HWY and I have the 5-speed. My friend has a set of 33", and
his overdrive (5) has been affected as has his mileage..

[Jacket]

I can only add that I don't think there would be much difference going from a 31" to a 32" tire if the two tire sets are exactly the same. If you go from a 31" passenger tire to a 32" LT, 8 ply tire, then the extra weight to turn 4 of those tires will have some burden on your MPG, probably 1-2 (adjusted) mpg less.

[uberhahn]

On my '99 4runner I never got better than 17-18 mpg, regardless of how I drove (mainly highway).

Tires were 265. Lift was 3in. Sadly sold last year...

[ken_79-fj40]

I've had 3-3.4/5spd tacomas, 2 of which had 33's and one had 32's. With 33's I got 18 pretty consistently. With 32's I got 19, only 1mpg less than when it was stock. All 3 had 4.10's and no issues with power. But they all had 31's stock too.

[Huhwhye]

Originally Posted by Jacket

I can only add that I don't think there would be much difference going from a 31" to a 32" tire if the two tire sets are exactly the same. If you go from a 31" passenger tire to a 32" LT, 8 ply tire, then the extra weight to turn 4 of those tires will have some burden on your MPG, probably 1-2 (adjusted) mpg less.

Yes but...

265-70-16 BFG AT's (at 51 lbs) weigh more than most 265-75-16 LT tires, which are usually in the mid 40lb range.

My friend has an '04 Taco with an auto. He had 75 series Revo's and lost MPG compared to the heavier 70 series BFG's

[Jacket]

Originally Posted by Huhwhye

Yes but...

265-70-16 BFG AT's (at 51 lbs) weigh more than most 265-75-16 LT tires, which are usually in the mid 40lb range.

My friend has an '04 Taco with an auto. He had 75 series Revo's and lost MPG compared to the heavier 70 series BFG's

BFG AT's are neither "passenger" tires (my quote), nor are they "stock" tires (you're quote). The stock BFG's on Tacomas are P-rated Rugged Trails (not AT's), and don't come close to weighing 51 lbs - more like 30-something. I'm sure the stock Dunlops or Goodyears that come on a 4Runner are the same. Therefore, if you went to a set of 32" Revo's (for example), they weight quite a bit more than the OEM Rugged Trails (or the OEM GY's/Dunlops on a Runner), and you'll see that in your MPG.

I think you need to be more clear about what tires you have, and what tires you intend to get if you want better input. To your point, a 32" tire can vary widely by weight, but since you are aware of that, you should also know that your 32" tire should be of similar construct and rating if you want to keep your mileage on par with your 31's.

My point was simply that the tire weight will influence your MPG more than the extra 1" diameter. If you use the exact same tire model, but go up 1" in size, the difference will barely be noticeable.

[Huhwhye]

Originally Posted by Jacket

BFG AT's are neither "passenger" tires (my quote), nor are they "stock" tires (you're quote). The stock BFG's on Tacomas are P-rated Rugged Trails (not AT's), and don't come close to weighing 51 lbs - more like 30-something. I'm sure the stock Dunlops or Goodyears that come on a 4Runner are the same. Therefore, if you went to a set of 32" Revo's (for example), they weight quite a bit more than the OEM Rugged Trails (or the OEM GY's/Dunlops on a Runner), and you'll see that in your MPG.

I think you need to be more clear about what tires you have, and what tires you intend to get if you want better input. To your point, a 32" tire can vary widely by weight, but since you are aware of that, you should also know that your 32" tire should be of similar construct and rating if you want to keep your mileage on par with your 31's.

My point was simply that the tire weight will influence your MPG more than the extra 1" diameter. If you use the exact same tire model, but go up 1" in size, the difference will barely be noticeable.

BFG AT's are BFG AT's. This is an off road forum and nobody here should be confused by that. Rugged trails are car tires and are not BFG AT's. And yes 265-70-16 BFG AT's weigh 51lbs.

I thought I was pretty clear. But for you I'll spell it out

BFG All Terrain K0's in size LT265-70-16 Load range D weigh 51 pounds per www.tirerack.com My friend with a 2004 Toyota Tacoma Extracab 4wd got less MPG (that's miles per gallon) with Bridgeston Dueler A/T Revo's in size LT265-75-16, I'm sorry but I don't know which Revo's he had in this size but all except Load E weigh less than the above mentioned BFG AT's.

Not all smaller tires are lighter.

I need to be more clear? After all you are the one that started talking about weight.

I'd assume we are comparing the same tires. 31 vs 32 in xyz tire.

[Jacket]

If I didn't know any better, I'd say you were getting a bit snippy.....understandable when your talking yourself in circles.

Fact 1.

Originally Posted by Huhwhye

If I go to a 32" vs stock 31" tire what will be the effect

You said stock 31" which is not a BFG AT on any Toyota

Fact 2.

Originally Posted by Huhwhye

My friend has an '04 Taco with an auto. He had 75 series Revo's and lost MPG compared to the heavier 70 series BFG's

Your friend has an 04 Taco, and has gone from OEM tires to BFG AT's to Revos in 3 years???? "70 series BFG's" would presumably be the stock tires on the truck, which are not AT's. But if you say he's gone through 3 sets of tires in 3 years, including a set of BFG AT's in stock size after the OEM BFG's, so be it.

Fact 3.

Originally Posted by Jacket

If you go from a 31" passenger tire to a 32" LT, 8 ply tire, then the extra weight to turn 4 of those tires will have some burden on your MPG, probably 1-2 (adjusted) mpg less.

What I said is indisputably true, and is based off of Fact 1 where you stated you were going from stock to 32".

You can try and spin this into a BFG AT versus other AT argument all you like, but that's not how you began this thread. No one is disputing the size of a BFG AT tire here, but if that's what you'd like to do, feel free - its your thread. My posts still stand - indisputable.

[Huhwhye]

Since 31" is the stock size that's what I mean.

My friend has 130k miles on his '04. He is a field service guy and gets paid to drive his rig rather than a company van. He has had 4 sets of tires on it. 130k in 4 years is not a big deal.

I was talking about using the same tire in 2 sizes, but whatever.

I don't even know why I'm talking to you anymore. This is not helpful.

[cackalak han]

Originally Posted by Huhwhye

Yes but...

265-70-16 BFG AT's (at 51 lbs) weigh more than most 265-75-16 LT tires, which are usually in the mid 40lb range.

I'd love to hear which of these LT265/75/16's are "usually in the 40lb range".

REVO - 54lbs
Pirelli - 52lbs
LTX A/T2 - 52lbs
Geolander - 50lbs

Seems like every topic you start, you seem to piss people off. Good luck on getting any kind of help at all with that attitude.

[Huhwhye]

And what would be the point of that? To prove I was right. No thanks, I'll just conceed.

[cackalak han]

Originally Posted by Huhwhye

And what would be the point of that? To prove I was right. No thanks, I'll just conceed.

You're golden.

[NxNWLAHAR]

I've been checking this site out every now and then, and decided to join. Always seems to be some good discussions,advice, and opinions. I just like to see what kind of rigs people are wheelin' and what results they get with different mods. I just gave my '00 Tundra 4WD (w/ lotsa mods) a new home, and picked up an '08 Taco DC 4WD w/ Rear Locker (waiting in the garage for improvements).
Thanks for listening. See ya around.

[NxNWLAHAR]

Posted on the wrong thread by accident. Sorry for the foul. Lacking pc skills. My bad.

[Happy Trails]

Originally Posted by NxNWLAHAR

Posted on the wrong thread by accident. Sorry for the foul. Lacking pc skills. My bad.

No problem. Welcome to Mud!!