PLEASE help me decide what gear ratio is bes

Taaaaaaahoe? · July 8, 2003

Bought the 2001 2wd Tahoe LT few months back, I didn't however like the stock rims on it, and it also needed new tires. So I found on e-bay a set of 17in chrome wheels from a Denali...I always liked those wheels!

Anyrate, my truck came with the 3:42 ratios, which I think was okay for the 16 tire & wheel combo. But with the 17in wheel and tires it seems my tahoe can not get out of its own shadow.

The tire & wheel size i have now is the same as the z71 comes standard with... My mother has an 03 z71 equiped with the 3:73 ratio, and it seems to have much better acceleration than my tahoe does.

I have no plans for lifting, or larger tires from here out, so no issue there. Most part plan on keeping that aspect all stock.

So I decided I should just go with the 3:73 ratio But other say I can get more bang for my buck of I go with the 4:10's

BUT, How much MPG will I lose on the highway? I do do a decent amoung of highway driving, and don't want to run anything there. I do about 35 miles each way in highway for work. Granted I do a lot of city driving too. SO its a toss up do I go for the 3:73 or 4:10...or something else.

Your thoughts?

Sorry for lengthy post...Thanks in advance!

Mike

racer0175 · July 8, 2003

it depends on what you are gonna be doing....

if your towing then the 4:10's are probably better...if your just highway driving then the 3:73's will get you better gas mileage.

i have the 4.8l with the 4:10's i bought my truck used so i didn't have an option...i like it cause it gives me alittle more punch off the line....i will probably be getting a camper, or towing a trailer on occasion so this is fine with me...

since you went with the bigger tires the bigger gear with help with power off the line...just depends how much you want

its a trade off.....more low-end power and decent highway gas mileage, or even low-end power and worse gas mileage....

i would think the difference would be only a few mpg...but others probably know more than me....i can't remember what i get...

MarkD · July 8, 2003

3:73 will return you to stock, but don't expect any improvement in accelleration.

4:10's will give you some improvement in accelleration.

varmint2506 · July 8, 2003

If you are looking for the snappy hole shot, go for the 4.10's. Like mark said above, the 3.73's will put you back to approx. where you were before the wheel/tire swap.

Taaaaaaahoe? · July 8, 2003

Guess it comes down to..

Do I want to go back to stock acceleration, or slightly better.

So if I do go with the 4 10s any idea how much worse gas mpg I would get than the 373?

And in theory, it should actually HELP my city MPG going with the 410s right?

Man, such a toss up.

Oh, will 410s make the truck not have any passing power, would it be a dog on the hwy?

ps with 5.3 motor

Mike

varmint2506 · July 8, 2003

You can figure that you will pick up close to 250 RPM going up from a 3.73 gear to a 4.10. You will probably loose a couple miles per gallon. It has been a long time since I have fooled with gear changes. Most of the ones I have done were with drag cars and mileage was a mute point.

You will have plenty of passing power with 4.10's, I wouldn't worry about that.

Based on what I'm reading into, I think you would be happier with the 4.10's.

Chris97K1500 · July 8, 2003

Typically lowering gearing, like the 4.10's will only hurt top end speed, not normal speed ranges. 4.10's will definitely make you get to a high speed faster, but 3.73's will probably have a little more speed top end in the long run. If you drive under 100mph, the 4.10's will pass and tow better than 3.73's. My father and I have the exact same truck, except his has 3.42's like yours, mine has 4.10's. There is no comparison, especially considering we both have 33's. I typically get 14-15mpg, he gets 15-17 with the 3.42's. So it's about 1-2mpg difference, which for the trade off in power and towing, isn't much at all. My vote's for the 4.10's. Chris

greyghost03 · July 8, 2003

Hey Taaaaaaaaahoe, I am trying to decide this same thing myself! I posted a question on this but didn't get much response so I am glad to see this!

My truck didn't come w/the LSD so I'm looking to add one.

3.73 gears & posi-trac Anybody installed?

Not trying to sidetrack your topic, I just have the same questions!

BlackSilver · July 8, 2003

Unless you're going to use it to regularly pull serious loads, the 3.73 is the way to go.

The 4.10 will give you more low end smoke, but that 5.3L has a fairly nice torque curve for passing acceleration, so what's the point?

The constant 300RPM increase at road speeds with 4.10's would suck.

Shaners · July 9, 2003

3.73's are a great all-around gear ratio. They will allow for decent towing, and still give good highway MPG's.

My suggestion is, that if you want to "hotrod" a little, or if you live in hilly terrain, and if you don't put big miles on your truck, then go with the 4.10's. That gives you the option to go with a lift and bigger tires, and it still gives decent MPG's. Some people that live in the conditions that I described, actually pull better MPG's with the 4.10's...

Taaaaaaahoe? · July 9, 2003

Doh!

Just when I feel I have made up my mind!!

Also...Can I keep my OEM Limited slip with new gears? OR do i have to upgrade that too..?

Thanksa lot guys!

Mike

bigtruck21 · July 9, 2003

Sorry about the first link

http://www.andthensometoo.com/calc/tiregear.php

http://www.web-cars.com/math/tiresize.html

http://www.csgnetwork.com/multirpmtirecalc.html

http://www.4lo.com/geartable.html

http://www.pajeeps.org/GearCalculator/tech_calcs.htm

Hope these help both of you.

100R1 · July 9, 2003

Tough question, as the answer will depend on your style of driving and actual intended use of the truck.

Here is a web site to help calculate wheel / tire size & gear ratio selection

http://www.c5-corvette.com/tirecalc.htm

My '01 yukon has 17" escalade rims with 265 70 R17 tires with a 31.62" O.D.

which is 1" taller than the factory stock tires

by doing so this changes my effective rear gear ratio to 3.61 from my factory stock 3.73

one of my intended uses of this vehicle is to tow a 5,000 lb travel trailer, If I have any problems my next step would be to change to a lower aspect ration tire to lower the O.D. of the tires.

greyghost03 · July 9, 2003

Sorry about the first link
http://www.andthensometoo.com/calc/tiregear.php

http://www.web-cars.com/math/tiresize.html

http://www.csgnetwork.com/multirpmtirecalc.html

http://www.4lo.com/geartable.html

http://www.pajeeps.org/GearCalculator/tech_calcs.htm

Hope these help both of you.

Thanks alot!

rtbrick · July 9, 2003

You know, all I have done recently is change tires from 265 to 285 with 3.73 gears and my truck feels like it is "dogging" a bit. It just does not seem to accelerate enough. I do most of my driving around town (thought I am getting to drive about 30 miles hwy, each way, 4 days a week) and have been thinking about changing to 4.10 gears to improve acceleration. I wonder about going on up to 4.56. That would probably be too low.

The wheel and tire calculation website said my gear ration only went down to 3.72. Someone else calculated 3.39 a while back. Which is correct?