Folks with 4.30 or 4.10 Gears running 33" Tires. Fuel economy?

[A.Wilson013]

Hey guys, looking for some feedback.

Ever since I put 33" tires on my 4Runner with 4.10's my fuel economy has SUFFERED. I fully expected a drop to 16-17mpg highway (from 19-21) and 12-14mpg in town (from 15-17).

That is not happening. I am averaging 13-14mpg in town, and 14-16mpg on the freeway. If you throw some wind onto the drive I drop to about 12-13mpg on the freeway (going 60mph).

I am assuming that this is because my gears are so tall, causing my engine to work harder... But I also have a hard time believing that this is normal... Are you guys struggling this much?

I am shopping for gears now, but would like some feedback.

If you could simply post something like this, it'd be greatly appreciated.

Year: 1999
Tire Size: 285/70/17
Gears: 4.10
MPG City: 13-14
MPG Hwy: 14-16

 

[SCRunner12]

Year: 2000
Tire Size: 285/70/17
Gears: 4.30
MPG City: 13-15
MPG Hwy: 16-18

I work about 12 miles from home which is 95% freeway driving and a mix of city driving when I get home and I typically get about 15-16 total mpg for the tank. That is unadjusted and there are a few big hills on the short trip to work. I get about 18 on straight highway road trips though, but I also need to replace my O2 sensor. It sucks, but nothing I can really do about it, so I live with it. I did just look at my last year of fill ups and I spent $3,800, that hurts to see.

 

[A.Wilson013]

Year: 2000
Tire Size: 285/70/17
Gears: 4.30
MPG City: 13-15
MPG Hwy: 16-18

Perfect, thanks for your input.

Essentially what this thread will do is decide for me if I am going to buy 4.30's for cheap, or shell out a bit more for either 4.56's or 4.88's.

 

[SCRunner12]

I would skip the 4.30's and just go for 4.56's or 4.88's. There will be a really negligable difference between the two and you'd be wanting a lower ratio. 4.56's might not be bad with your supercharger and it would keep the hwy rpm's down. Are you planning on addding armor at some point?

 

[Kraze]

I don't have 33s, but on my last couple trips out of town, I've averaged about 18.5 mpg with my 35s and 4.10s. I don't have any city numbers.

IMO, if you're going to pay to regear, you might as well make it worth it and go 4.88. You would probably barely even notice going from 4.10 to 4.30.

Edit: Have you calculated in the tire difference in your MPG figures though? Before I did, I thought I was getting ~15 mpg on the highway. After I got the torque app and was able to see how far my odometer was off, that MPG figure jumped way up since I was able to calculate it with the actual miles driven.

 

[blonde1boarder]

This relates to what Kraze is saying above. When I was calculating my mpg I took the ratio of the stock tire size to the new tire size(in my case 315/70/17) and used that to find how far off the odometer was. I ended up getting around 18 mpg which isnt bad. Math below:

265/70/16 ~ 30.6"
315/70/17 ~ 34.3"

Ratio = 34.3/30.6 -> 1.12

Odometer Reading -> 237

Actual miles covered = 237*1.12 -> 265 miles

Gas at pump -> 14.8 gal

Actual gas mileage = 265/14.8 -> 17.9 mpg

All on 4.10s

 

[fourwd1]

And what trans do you have?
Auto vs manual will affect mpg and what gear ratio would be appropriate for the tire size.

 

[Brian757]

I have 4.10's with 33" tires. The winter is going to suck :sobbing:

I get-
City: ~12-14 MPGs
Highway: 13-16 MPGs

 

[KidVermicious]

I have an auto with 4.30 gears and 33s, no supercharger, and it sucks. No power, and I'm lucky to get 16-17 mpg on the freeway. That's at 5000 feet, but still.

You might maybe get away with 4.56, but I've learned over a couple of trucks that it's always better to overgear. I'd go to 4.88s.

 

[crazydubman]

I have 4.88's in my 97 limited runner now but I have a little more rolling weight than most with the beadlocks. It feels about right now going from 4.30's to 4.88's. Then again, I have 112lbs a corner for beadlocks and tires, front and rear bumpers with carrier, roof rack, full storage shelves and military storage cases in the back and a full size beadlocked spare. And to top it off, no super charger.

I have my 4.30's I just pulled out for sale if your interested. Front clamshell and rear E locker housing. No actuators unfortunately as I needed them for the new diffs. Both work great with no bearing noise or leaks.

If you were to go with new diffs say from ECGS or something, I would look into 4.56's with the supercharger.

My fuel economy is not great as you can imagine. Only about 13-14 combined. I tend to drive 65-70 on the highway though and I live where there is traffic everyday on my commute.

 

[dunktap]

right there with you

just upgraded to 285/75/16 duraracs and just god 14.9 mpg on my first tank. I have 4.10's and am looking at regearing with ECGS to 4.88

 

[Millerad1651]

98 SR5 4x4 w/ 4.10s I believe.
285/75/16s. I haven't broken it down between highway and city, as I take both to and from work everyday. But I get right at 17.5 combined. My wife does the same driving with 265s on her's, and averages 19...so I'm not too upset with what I'm getting.

 

[white_n_slow]

285/75r16 Coopers (a little undersized, but full tread)
16mpg highway (going way faster than I should)
17mpg highway/city mixed
4.10 gears
5-speed

This is verifying mileage with GPS since my odometer is off due to the tires. If I actually drove the speed limit I think I would be doing about 17 or 18mpg highway.

I also don't think 4.30 gears would make much of a difference, and if you're ponying up the dough for aftermarket gears, 4.88 allows you to run a 33 or 35 inch tire without getting too out of whack, so that would be my preference over 4.56. This is just from a driveability standpoint. For MPG, I think you're boned any way you go.

 

[Fishwerks]

Year: 2000
Tire size: 285/75/16, load range E
Gears: 4.10 (I'm assuming, auto trans and no e-locker...)
MPG City: 14-16
MPG Highway: Anywhere from 17-20

This is with a supercharged 3.4 with no fuel mods.

 

[A.Wilson013]

Thanks for everyone's responses.

To answer your question Kraze, I have not been accounting for the larger tires in my calculations.

My transmission is an auto =(

 

[SCRunner12]

I tend to drive 65-70 on the highway though and I live where there is traffic everyday on my commute.

Ha, not when I was following you to the BAMF mod day. :cheers:

 

[4-Ripcord]

As someone who had 4.10s for a few years then swapped to 4.30s, I can tell you that 4.30s get less mpgs.

my highway mpgs dropped by an average of about 2 when I switched. City mpgs suffered but not as much. Yes I had more power and offroad it was better, but if you dont go offroad much I would do 4.10's.

 

[4-Ripcord]

Also not sure why your mpgs suck so much. We had like the same drivetrain setup and I got like high teens sometimes low 20s on 33's.

 

[crazydubman]

Ha, not when I was following you to the BAMF mod day. :cheers:

Ya ya... haha. Ok maybe 75.

 

[mcaz5]

I've got 295/75/16 on 4.10 gears.

I get about 15-16 around town, 17-18 on the interstate, and 19-20 on back roads.