went from 14-16mpg down to only 12mpg........

i finally upgraded to 18" aftermarket wheels and nitto 35" grapplers and i imediately noticed a difference w/ the larger, heavier tires. taking off from a stop was much more slugish and rpm's on the hwy were much lower now. before i bought the tires i figured stop and go would cost me mpg but i would make it up on the hwy w/ lower rpms. but w/ my 3.73's now my rpms are way too low. now i see that they were where they needed to be in the first place. now i knew this was gonna cost me mpg all around. i had dodge try to recalibrate my odometer so i could hand calculate my mpg, but they could not recalibrate to 35's. they could only calibrate to about a 33" on 06's.

anyway to make a long story shorter, what i did was took my wifes brand new 08' trailblazer and drove a route on the backroads from a standing start point to a stop point exactly 1 mile, then double checked it again. then drove my truck the same route and double checked it too. my truck read .9 miles, so my odometer is off by .1 for every mile driven, basically i have too add 10 miles for every hundred miles my odo. reads and then another mile for every ten miles left over.

i used to get anywhere from 14-16 mpg driving city/hwy mixed. now on these same local routes w/ my first tank of gas on my new 35's i barely made 12mpg

 

I am running 4.10 gears with LT315 (aka 35s) BFG AT KO tires. Around town I can pull 15-16 mpg and cruising on the highway I easily get 17-18.

I recently added an air intake and air manifold, which hopefully will help with the MPGs. I do not drive my truck a lot, and am not really concerned with the mileage. The 35s fit the truck perfectly, IMHO.

 

It seems on every forum im on, that when guys put the big tires on and even leveling kits they loose MPG, at least if you go with 33`s they can dial in your speedo. good luck

 

im hoping to be able to dial in my speedo w/ the smarty i have on the way.....

thats another thing, w/ more power from the smarty i think my trans would be much happier on 33's, at least until i upgrade it anyway.

 

I noticed about the same results when I put on the 35x12.50x17's. About 2-3 MPG loss. My friend Tony put Hercules 315-70-17 Terratracs on his 05 auto and got 1-1.5 mpg better. I think it is the soft rubber compound and my tires are a good 2-3 inches wider.

When my tires wear out, I am going with a all-terrain in a 315 with a harder rubber compound.

 

Thats the main reason why I went with a 305/65/17 BFG, its a good compromise between looks and "like stock" performance. Sorry to hear that you were'nt happy with the performance of the 35's, keep us posted on the performance #'s when you get 33's

 

Can't figure out why someone would think by going with a taller, wider and heavier tire with an aggressive tread design will increase fuel economy. Lowering engine speed just isn't enough to overcome these obstacles.

 

im trying to score a set or almost new take-offs. i dont mind the goofy look of stock and am tired of the tires i have now

brett

 

Exactly! It gets said over and over but so many have to try it for themselves and be surprised. There is so much more to mileage than engine RPM.

 

look guys, i figured the larger heavier tires would cost me mpg but alot of guys on here swore they got better mpg on the hwy so i figured i would give it a try.

i wasnt expecting any gains at all, i was only expecting a slight loss in mpg.

 

A few guys have gone with the Interco Vortracs. They're a little bit narrower and are "E" rated. The big question is wear and ride quality. I haven't read anything at all from the buyers yet.

 

The tires that gave me the best mpg were the bfg 265/70x17s that came on the truck. The next best were ProComp 33/12.50x17 a/ts. I'm now running 285/70x17 ATZs that I don't like. Can't even get into it with out them spinning.

 

went from 33" mtz's to 35" toyo m/t's and have lost less than .5 mpg. i don't do much city driving, and my rpm's with the 6 speed and 3.73's on the highway are MUCH better. also toyo m/t has a friendlier highway tread and harder compound.

 

Anyone change out from 3.73 to 4.10 ratio gearing? How much? I'm going to get 18" rims and toyo mt's, but dont want to loose performance so am also looking at changing the gearing....course all of this has to wait until after the lift pump and the turbo...

 

most people i know who went to 4.10's, who do lots of highway driving, ended up going to 37's to get the good highway rpm's back.