Hi everyone.
I have been lurking the forums but have not found what I am looking for.
Recently purchased a 98 1500 with 6 inch lift and 35 inch tires. It has the 5.2 engine
It runs really good and I have no major complaints. The one question I do have is should I change the gear ratio?
It has the stock 3.55 with the anti-slip. I do not tow much if at all. All i am looking for is gas milage and increased life of the drive train.
Should I spend the money and go to a higher ratio? Will I save that much in fuel?
I drive like an old lady around town. It sees some highway but not alot.
If this has been covered else where, please point me in the right direction.

Thanks

 

With 35s at least a 4.56 gear , yes it will save wear and tear on the the driveline and help the MPG , all around its a win win ...

 

4.56's are good for fuel economy with 35's, and 4.88's would be better if you haul or tow anythingwith your truck

 

Thanks for the good info. Sounds like I need to be sure the gearing is correct.
So, I asked the guy I purchased it from if the gears were changed. He said he purchased the truck like it is so he does not know the gearing.
Next question. How can I figure out what gearing it currently has?

 

http://thedieselgarage.com/projects/...c/tirecalc.htm

There are multiple calculators on this site.

They give you pretty good instructions

NOTE* our trannys have a .69 to1 ration in overdrive

 

Have you tried the search function? I guarantee it would answer the two questions you've asked. How can I guarantee you ask??? Well, because I had the same question a few months ago, used the search function, and decided on 4.56's to push my 35's.

Depends on how much you weigh the cost with the wear and tear it's putting on your engine. Reading some of the old posts about this will help you come to the conclusion yourself.

Jack the truck up so both rear tires are off the ground. turn the tire and watch the driveshaft. Count the revolutions. 1 full tire turn w/ a little over 4 driveshaft turns = 4.10's...Once again, the search function would've yielded you your answer in a few seconds. I'm not trying to be a ****, it's just that most of us are getting extremely tired of the same questions.

 

Hey man I have a 360 and I'm runnin 35s and I have 4:56 gear ratio and it was definitely worth. I noticed like an instant 3mpg increase, and thats a lot for me because I usually can't keep my foot out of it. But all in all its definitely worth it. I wish I would have got 4:88 but then again I care more about power than MPGs but its up to you

 

Thanks for all of the replies.
Sounds like a decent investment. After I read my first post I was sure I would get flamed. First I say I have stock 3.55, then I ask how to find out what my rear gear ratio is. DUH!
I need to do the math and figure out what I have now. The truck seems to have good power now. If they are stock and I go to 4.56 I am gonna love it.
Thanks again.

 

4.88's is going to give you more low end (the power I assume you are talking about) actually...4.56's yields lower rpm's at any speed. The lower you go beyond a certain point, the higher your revs. If you are now spending the majority of your time above the "sweet spot" you are drastically affecting your mpg's. If you want better mpgs, go 4.10's.

 

Do not do 4.10's with 35's, it is not good for your gas mileage. 4.10 with 35 is too low, you can't even run in the low rpm's (overdrive) without it constatnly kicking you out of OD. This uses far more fuel. For good mpg, you need a gear that will allow you to run in OD comfortably without constant downshifting. Go with 4.56. I'm still leaning toward 4.88, but i'm not yet decided.