I know we have talked about this some but just wanted to get all the new and oldanwserson one page. Going from 3:42 to 4:10 will hurt gas mileage is what i am told. But also what will it do if you do it and have large tires like i have 285 70 r17 and 3:42 will 4:10 work better with this tire size and not effect the gas mileage?

 

yours may not be quite big enough to need the move to 4.10s but you're on the right train of thought... it helps undo the performance loss with bigger heavier tires

 

410 does not hurt mpg..it KILLS it

 

what about a change from 3.42 to 3.73? how much mileage are we talking, like 2 mpg or 10? i can deal with 2 to 4 mpg

 

the lower the number like 3.73 give you more tourque lower end but worse higher end and 4.10 will give you less tourque off the line but will help you higher end on the highway 4.10 will help mpg for around town drop you pants and bend over

 

Hey guys, listen to the complete question. He has added 33" tires so what are the benefits of going to 4.10. The answer is since you have gone to larger tires, you need lower gears. 3.73 will be similar to stock 3.42 with stock tires. But 3.42 is too low for stock if you want performance. So with 4.10 you will lose milage over 3.42 stock, but gain alot of performance. Top end will not be affected much as you are looking at over 140, which the truck won't get to due to weight and wind resistence. So going to 4.10 will give you similar milage to what you have now, maybe a little better since you are now cruising out of the power band. 75 mph you are only turning 1500 rpm instead of 1800 where you should be at 3.73. I would recomend 4.10 since I know you like power and don't want to loose milage. But the added performance will be awesome. If I could afford it I would put 4.10 on in a heartbeat, but not 3.73 with 33" tires on your truck. Each year is different, but I have done alot of research on this year as it is the same as mine.

 

I know you had looked in to it alot smoke20 so preety much 3:42 with stock 265 70 r17 would be the same but better power with 4:10 and 285 70 r17 is that what your saying. Where if i had 265 70 r17 with 4:10 it would kill my mileage. Is that why if you get like 35 or 37 inch tires you want even bigger gears then 4:10 correct?

 

I am turning about an even 2000rpm at 75mph. Course I have the 4.8liter so I guess it has to work harder than ya'lls 5.3's. And for my .02 cents worth hunt4game29, everybody I've talked to that has had 4.10 or higher gears has said it killed the gas mileage but made it a lot quicker. If gas mileage is gonna be an issue for you I'd suggest putting the money into something else, if you have $1,500 to blow on gears, you only need another $1,100 to get a Wynjammer supercharger. I'd just save the money. Course I'm sure a supercharger is going to affect mpg as well.

 

What do you guys think of this website.
http://www.4lo.com/calc/geartable.htm

 

Speaking of bigger tires and gas mileage......
I plan on upgrading wheels and tires and would like to go bigger sizes with both for looks. My current factory setup is 265/75/16. Is there any way i can go with 18" rims and a little larger tires (33") without killing my trucks power and mileage???? my Z71 comes factory with 3.73s