4.30 vs 4.88 on an auto with 34's

Yet when i posted asking if anyone went to 4.30's for an AT folks balked like i was a moron. Unfortunately like what has been said is most shops are one stop so my only option is 4.88's.

 

You can get the shop to order from EastCoastGearSupply.com and get either 4.30 or 4.88 gearsets for the 3rd Gen 8.75. Or you can get 4.10, 4.30, 4.56, 4.88, or 5.13s for the 8 inch rear.

 

Probably because the cost isn’t worth a negligible gain.

People with 4.88s report the same mpg so why spend the money on something that nets you very little performance improvement.

 

That's because 4.88's are the groupthink option for 3rd gens.

Just like everyone says you need to run a 3" lift and CMC to run 33's at the very minimum...don't always believe what you see on the internet. I run 4.30's with an AT, and also have 33's (285's) on stock suspension with very little inner fender well modifications and no CMC, doesn't rub either.

 

I can tell you right now, I do NOT get 19.5-22 MPGs with 4.88s and 33s. 16.5-17.5 is about as good as you get and that's with OV's tune. 4.30s with 33s will put you back to what the gearing was before larger tires... Basically, back to stock with just a little more gear to assist with the heavier tire. Arguably, 4.56s would prolly be the better route but you would still be over gearing for the tire size.

 

Just looking at numbers. Stock tires 4.30's vs 4.88's. 75 is nice with the 4.30's, a bit high with the 4.88's. Obviously with a taller tire those rpm's come back down.

 

You also have to factor in a 15-30% reduction in RPM when the Torque convertor locks... So it is safe to say at 70MPH with 4.30s and 32.5-34 inch tires you'll be running 1800-1900 RPMs. That should net you back to very close to stock with a tad bit of umpf for the heavier tire.

 

That's why I went with 4.30's...my commute is 40mi of 75-80mph highway speeds...4.88's would have been too much gearing and killed my gas mileage.

80mph and I run about 2100rpm, which keeps it from downshifting into 4-5th.

 

these numbers are with it locked.

 

I guess it just comes down to how you drive. I never get 19.5-22 on a tank, I might on a single trip but my tank average is usually 18-19. Whats odd is that both the MT and AT average 18-19 yet the final drive ratios for an MT with 4.30s is similar to the AT with 4.88, in fact the AT with 4.88 still has a higher final drive ratio in 5th and 6th than the MT...

 

Before I re-geared to 4.88s and put on 33s I go a consistent 19.5-21.5 MPGs on the tank. Up to 23 MPGs on 60 mile trips with minimal hills and hypermiling.

 

Dang, thats awesome.

I have 5.29s coming in so I'll report what my tank mpg is on stock tires then on 35s.

 

I predict 14.5 on stock tires and 17 on 35s

 

I'm running 1.04 87. I use 91 for longer trips

 

Just an update on the 4.3 vs 4.88 decision for everyone. I found the tipping point for needing 4.88's. With 4.3 and 34's with minimal extra weight I was seeing around 18 to the tank consistently. After adding a full front bumper and winch it dropped to 14-15mpg to a tank. So due to the plan of getting bigger tires, not being able to use 6th again and shit mileage, I decided to get some 4.88. With about 400 miles on them I'm seeing about 17 to a tank again. So if anyone is on the edge about what to get I'll break it down based on my experience.
-30-32 with no extra weight = 3.9
-30-32 with extra weight = 4.3
-33-34 with no extra weight = 4.3
-33-34 with extra weight = 4.88
-35 with no extra weight = 4.88
-35 with extra weight = 5.29
**if you have the ovtune, you can get away with more weight due to the better shifting/ low end power gains**
If anyone has another opinion on this chime in and share your experience please

 

Man I forgot about this thread. I get about 19 on stock tires with 5.29s

@Weirich. Check out the 4.88 mega thread and 5.29 mega thread when you have a chance.

 

I tried to give it an honest chance but got tired of digging three post pretty quick.

 

4.88 or 5.29 if you are armored up. 2 buddies are running 5.29 but are heavy with 285/75/17

 

I just turned in my rusted out 97 4runner of 15 years for a 2020 Tacoma DCSB TRD 4x4 AT. The 97 was a great rig! I knew what I was getting into(known problems) with the 3rd gen Tacomas. I've read all the threads......lots of good info! I'm not looking to upgrade the tires, just need a little more power to limit the gear hunting.

I'm too new to post a new WTB thread. Any factory 4.30 gears for sale out there?

 

I think @Rus$ has a set still