hello I have stock 17's and 3.55 gears tires are about 31'tall. What would putting 27' tires on do to gearing?Would it be equal to, 3.92, 4.10 , 4.56? I would like to try this as appossed to installing gears in front and rear expensive . Also it would lower truck approx 2' to improve milage? I read people installing Gears that supposidly improve milage up to certain mph. would this be the same? Thanks in advance. Tires are goodyear wranglers 265/70r17

 

May I suggest the first thing to do will be to find out what size tires your truck was born with. The sticker on the drivers door jam will tell this. Post that info and we can work the math from there.

 

reindeerman tires are goodyear wranglers 265/70r17

 

79LRT – Just need to clarify. What tire size is listed in the drivers door jam? White sticker should be on the door its self.

Just need to be sure before answering. Things often change after a truck leaves the dealers lot. Things sometimes change before a truck leaves a dealers lot!

 

First off, let me apologize for voicing my opinion, but stop and think for a minute about how ridiculous your truck is going to look with tires under 30". The stock 265/70R17 convert to 32" check this link for a comparison....

Tire converter

I've seen some Ram's that come with 245/65R17 (or maybe its 245/70R17), but they look like little donuts. If the truck is 4x4, then just lower the torsion bars and you could pick up some mpg's. I did that a week before I lifted my truck just for **** and giggles, and it netted me 2 mpg more. If its a 2WD, then do the gears, it will be half the price as a 4x4. But please, don't give the Ford and Chevy guys an excuse to make fun of your truck because it has weenie tires on it.

 

Your tire size will be about 15% less, therefore, your effective ratio will be around 4.10.[sm=smiley23.gif]

And, yes, I WILL laugh at your truck, they will look like compact spares.[:'(]

second thought, I ain't sold on the "taller gears yield better mpg" belief. I get 12.5 mpg with 4.56 @ 75 mph. The truck is tall and heavy, though. Swami says "I see a civic in your future."[sm=lame.gif]

 

You must also think about weight ratings, too. I suggest you go to tire rack to compare tires and look at the specs.

Also, a 17" wheel is the smallest you can fit because of the calipers, so switching to a smaller wheel is not possible.