The 4.88 mega thread!!

I should add, I no longer need the Shift Sense Pro. When I need a little more, I just use the ECT.

 

As of today, I’ve gotten back up to 18 mpgs, when it used to average < 15 mpgs. Granted, I’m still within my break in period, but it’s thoroughly impressive on the highways.

 

My mileage sucks but it always has living in the foothills. There are no roads over 55 mph, even close. Average runs around 16 mph. I can get about 18-19 on the flats at 70 mph. With the extra power I can be more agressive, seen it as bad as 14.5. Get about 12.5 with a 3,000 lb trailer in the hills.

One thing I have noticed, the computer is wrong always, it has been as much as 1.5 MPG off even before changing gears. If I really want to know I have to compute it the old fashion way.

 

Thanks for all the info, you're making it a lot easier to make the decision on swapping the gears.

 

So i’ve reading a ton of info in here and thinking I may benefit from regearing over a tune. Although have to admit I’m not too sure. I have a 17’ tacoma offroad 4x4 with ome 3” lift. Just put on 285/70-17 Falken Wildpeaks. Now my truck drives very slow. But there only 32’s. I want to improve on take off from stop lights and when im in the 60mph range on freeway trying to reach 70mph. Both of those areas bog me down so much. Are 4.88’s right for me?

 

One word for you - yes!

I’m on 285/70/17’a and it’s a world of a difference.

 

With that gear ratio no issues running 75mph all day long? Looks like it revs high at that speed i do mostly freeway

 

REMEMBER WHEN YOU PUT LARGER TIRES ON YOU IN EFFECT LOWER THE GEAR RATIO - MEANS LESS TORQUE.

The only option is to regear to higher ratio and there is only one company producing gears and they are 4.88.

I only went up one size on the tires, 1" (265/75r16) and together my new gear ration is 4.73 effectively. Even at that number the performance is spectacular. Yes do the regear!

Here is a good calculator, You do the math and see what will happen.
http://www.4ws.com/gear-ratio-rpm-calculator

 

I was getting 12.9mpg at this speed before i went to 488’s

 

Exactly as @Cclogan8 stated. 2100-2200 rpms at 75mph isn’t bad and it’s always in the powerband without the constant gear hunting.

I also was averaging 12-13 mpgs fully loaded and yesterday my last highway drive was averaging 18 mpg making it was fun and easy to drive again.

 

That tire size is closer to 33" and most people will refer to them at 33's.

 

The auto should have come with 4.56 gears from the factory. Anyone running tires bigger than stock should probably get a regear.

 

Pulled the trigger after reading this thread. 4:88 going down tomorrow. ? for those who have done this. do i need to get a speedo repro

 

Im by you were you going and whats final cost. Ya you need a speedo if your tires are bigger than stock

 

If you spend all that money on the truck, spend a little extra to fix the speedo

 

NO speedo adjustment required if just doing gears. Apparently the ABS sensors provide data to the computer. But if you change tire size you need to buy the calibrator.

As for cost, the gear set was $1,325 at https://www.rogue-offroad.com/product-p/gptaco2016-4.88-8.75.htm and the labor was $1,100 at 4wheel parts.

 

I plan on installing 4.88 gears soon and I live in central KS. Any recommendations for gear shops in my area or relatively close in the Midwest?

 

I had my gears installed last week. Wow does it run better with 4:88. What’s everyone using for a speed calibration. I’m running a couple mph over what it’s reading with 285/75r16

 

Hypertech has an inline calibrator that plugs into the instrument cluster. Totally corrects the speedo.

 

Yes, as stated above, the Hypertech unit should fix it. Remember to measure the actual tire size vs what the manufacturer spec says it is. EG, my so called 33's are just slightly larger than 32".

OH, and I asked my dealer if they could recalibrate for me, but they wanted to charge me $495 that includes an inline module (probably a hypertech).