Re gear VS Tune

teej750 · January 26, 2012

I have a 2011 Silverado LTZ Crew Cab with a MagnaFlow Exhaust and a KN Filter replacement. Not a lot of performance mods. I have a leveling kit, and (will have20" wheels and 33 tires.) Im wondering what are the pros/cons of these two mods, and the average cost of each. Ive done research on the re gear and im wondering if it will help much for just a daily driver. I dont do any off roading and it looks like thats the main reason people do the regear. Id like to have more power w/o sacrificing fuel economy. I didnt know if these details would change whether or not id get a regear. Thanks in advance for all your help. Im not a mechanic obviously so i appreciate basic or logical explanations! lol

Will be posting pics tonight of the Black 20" monsters with 33" Wild Peak tires on the white silvy!

Big Whiskey · January 26, 2012

If you're only running a 33" tire, in my opinion, a gear swap is not worth the extra money. Changing the gears in the front and rear of a 4x4 can get pretty expensive in a hurry. The parts themselves aren't that pricey, but the labor costs will eat you alive. Plus, you'll have to get a tune after the re-gear anyway, to re-set your computer for the new gear ratio.

I can't speak from personal experience because I'm too worried about voiding my warranty....but I've heard nothing but great things about the benefits of tuning these trucks. I'd do the tune first, and see what you think.

StarsnBars · January 26, 2012

Wait till you get the new tires and rims. You wont feel much difference. Your MPG will drop alittle. I went from 265's to 33's and couldnt feel any difference. Just a small mileage drop. Maybe a tune , but gears are not worth the cost for that swap.

cracked_up · January 26, 2012

I guess my question is what engine and gears do you currently have?

I am running 3:42's with the 6.2 and it's fine with 33's on, now if I had a 5.3 with 3:08's I may consider regaering.

Stevens03 · January 26, 2012

I guess my question is what engine and gears do you currently have?

I am running 3:42's with the 6.2 and it's fine with 33's on, now if I had a 5.3 with 3:08's I may consider regaering.

x2....

If you regear, your re-tuning too

4wd truck will cost you about $1300-$1500 for gears, master rebuilt kit and installation

2wd truck will cost you about $500-$600 for the same stuff.

Plus you have to add some sort of tuning to adjust for the gear swap.

If you tune,.. you'll pick up some power to help compensate for the little taller tire and heavier wheels.

If you have 3.08 gears, I'd def consider re-gearing to 3.73's to offset the difference in tire size and I'd bet your mileage would stay the same or close to what your getting now. When adding the larger tire, your going to see a mileage drop anyways and your speedo's going to be off some too. A tune would fix that.

teej750 · January 27, 2012

Im actually not sure which gears i have. Ill find out when i get home. Its a 2011 Silverado Crew LTZ Z71 5.3L. I test drove the 6.2 and it was a beast and only 1K more. Kinda wish i woulda bought it, but the 5.3 was enough to make me happy and liked the gas mileage. But i want some more power. If i could go back i might get the 6.2 instead, oh well.

Stevens03 · January 27, 2012

Glove box... RPO codes.

Look for

GU4 3.08

GU6 3.42

G80 Lockers

teej750 · January 27, 2012

Glove box... RPO codes.

Look for

GU4 3.08

GU6 3.42

G80 Lockers

It says Rear axel 3.42 ratio.

tyhuck · January 27, 2012

Get the tune, then see where you stand. You will need the tune regardless to adjust for the difference in the tires same as if you had regeared. So, get a Black Bear tune now to unleash some hidden power and fix the speedometer. Then if you need more torque, get a regear and have Justin change the program so that your speedo is right again.

nickvrebel · January 27, 2012

what type of driving are you doing? I've done a gear swap from 3.42 to 3.73 on a 4 speed truck so I have some personal experience here....

I actually gained MPG (not much, maybe 0.5-1) with the more aggressive gear because the truck wasn't struggling as much in stop and go traffic. My highway mileage stayed the same. I traveled a lot of hilly highway and the truck wasn't downshifting as much.

Now, know that the gear ratios are totally different between the 4 speed transmission and the 6 speed. Personally I am more than happy with the 3.42 gears and I think they are plenty low enough on the bottom end.

on to tunes.... (I also do my own custom tunes):

you will need a tune if you change gears - it will be necessary to fix your speedometer and transmission shift points.

a tune can also get rid of (most of) the throttle delay, make the motor more efficient, adjust transmission shift points to where you want them, adjust transmission shift firmness/speed and a ton of other variables. Personally I have my truck tuned for fuel economy, I can achieve 23 mpg in my truck on a round trip to my hunting camp.

another thing to keep in mind is driving style and the planned over sized tires will also affect your fuel economy.

My recommendation would be to talk with an experienced tuner first. Make sure he understands your goals and is honest with you about expected results. If you want "all the power I can squeeze out of it and 30 mpg" you are wasting your time. There is certain trade offs for fuel economy and speed.

SouthCo · January 27, 2012

I've got the 5.3 and 3.42 gearing too(max or hd trailering pkge or whatever they call it). Stock diameter tires are about 32" so you are only going up by 1". You probably wont even know the difference. So regearing for such a small change makes little sense. As others have stated, regearing requires tunning.... So get a tune 1st and it'll be better than when you started (if you get a 93 octane tune).