:confused013:

 

I Didnt notice anymore power..Seemed worse w/the 15lbs a piece heavier mud grips..also mpg went down a lil..about 1.5-2mpg,but it looks good so I guess it was worth it to spend $1900 on tire's to get less fuel mileage..lol

 

Bigger tires will slow ya down a bit. But I like how it lowers RPM's on the highway.

 

You are right..I think after these tire's wear out I will go to a lil lighter,and smaller,and do the 3.42 gear swap from the 3.73..The G56 tranny is not good for lower rpms at 70 plus mph..after 70 the mileage gets real crappy,especially if i'm pulling something..

 

I was thinking that maybe bigger tires (and the resultant lower gear ratio) might put more of a load on the turbos and help with spoolup and overall HP/TQ output....

 

Although I may see a lil quicker spool-up because of the added load of pulling the heavier tire's,the end result is a bad trade off showing no gain in performance,just a lil slower and worse mpg..kinda feel's like it did when I ran the 245/75/17's and pulled my 14 foot trailor w/2 4-wheelers on it..about 12-1500lbs..

 

my truck has aweful lag at 70mph but its only turning over 1600-1800 rpms so it saves me on fuel. But I'm also running 37s.

 

I went from stock size to 285's and the your only gaining about an inch in height. The slower spool up is barely noticeable. With bigger tires you will usually see a reduction in hp and tq.

 

My tire's measure 32.7 from firestone,plus they a mud grip,instead of the all season tire that wason it when i bought it..So it was a good bit taller,heavier,and wider,I had to run a half inch spacer to keep the rears from touching..

 

Anyone have any Dyno #'s to substantiate the perceived decrease in HP/TQ when going to larger tires? BTW going from 265/70/17 to 285/75/17 is almost 2 1/2 " increase in OAD....

 

I don't have any dynos done to my truck,but you could go to 4-Wheel Off Road magazine web site..They have done numerous dyno comparisons..The bigger,and heavier the tire,the more power you lose..That's why they recomend gear changes,to help reduce the rolling resistance of the taller,heavier tire..The gear change wont get you all your power back to the rear wheels,but it help's a lot.Good luck!:thumbsup:

 

From the stock size Generals that were on my truck to the 285's that I put on was only 1".

 

Then you must have 285/70/17 NOT 285/75/17's (See original post)

 

Probably, cant remember and its 11:00 here and Im not going outside to look. Theres only one way to find out put them on and see what happens.