I average around 16mpg with the tire size difference calculated in. The truck came stock with the 285's. I am thinking about getting rid of the 315’s and getting a set of 305’s. The 315’s tend to rub a little if I turn hard and it’s driving me nuts. My truck has 4:10 gears and I bought it with 315’s on it. I am wondering what this will do to my mileage.

 

Correct me if I'm wrong but I swear that I've read here and else where that the biggest tire from the factory was a 265/75/16. My 02 has the stock tires on it still and they are 265's. I also have 4.10's but with an auto. From what i've been told, 285's will give you a little better highway mileage but the city mileage might go down due the the larger tire, this is compared to a 265 i would imagine.

 

If you check the label inside the driver side door jam, you'll see that the truck (probably) came from the "assembly plant" with 245's.

I got mine from the "dealer" with 265's, but when it rolled out of the assembly plant, it had 245's according to the label.

 

the narrowest, tallest tire will give you the best milage with your 4.10s. I'd go for the 285's. I gain about 3 mpg with my 235/85 vs. my 315s.

 

I've run them all, 265, 285, 305, 315's and the best highway mileage has been with the 315's, the best city mileage was with the 285's.

285's don't rub, 305's will depending on what your doing, 315's all the time.

Jeff

 

My truck came with 245s stock

and what u said about the mileage is dead on, i get better highway mileage than city mileage, but my speedo is off by 5 mph most of the time now, and my fuel mileage by about 8 percent over stock size...

Rick

 

I get worse mileage now than I ever have with my 315's. I run about a 50/50 mix of city/highway driving. I am planning on taking my 315's off and putting 285's back on. The big tires just feel different. It doesn't drive as good, giddy up as good, and gets worse MPG's. The only pro IMO is that they look better. I wish I never would have sold my 285's. Im planning on getting some new wheels and I am gonna trade my 315's off for some 33x12.5/17's. I have been pulling heavy with my truck lately and the 315's just aren't practical.

I would get some 285's or 305's with an all terrain tread pattern.

 

Yep! everyone is correct -> my 2001.5 came with 265's and there are some out there that came with 245's. 285's will not rub at all. I installed a 2-3" suspension system and now running 315 Toyo's (35's) and actually get 1.7 - 2.3 mpg better than with the stock 265's. The 35's do rub a tad at full lock but only when turning hard right at full lock.

A pure stock truck would suffer mpg without some type of performance increase. Think about it - 265's weigh about 55 lbs per tire where as 35's are about 85 lbs per tire. More mass to rotate.

I am running a Edge-EZ box with the Smarty which allows for this difference and actually provides more HP and a increase in mpg. Now this may be different in your case depending on elevation or major grades. But for interstate and highway driving I would take my 35's over any 265 or 285's with my setup. I average about 21.9 - 23.4 mpg when I'm not blowing smoke!!!

 

305/70/16s and 285/75/16s both have about the same diameter, roughly 33". About 1.5" less than a 315/75/16. Your engine will be turning at a higher RPM with the smaller tires. But you will have less rolling resistance. Personally, I doubt that you would see much of a change in fuel economy.

The experience from people with 3.54 gears in their trucks really isn't applicable.

 

I've run 265s, 285s, and 315s with 4:10s 4x4 and like the 285s overall,
However the taller 315s were better for fwy rpms.

 

Thanks for all the information. I think I'm gonna sale the 315's and get a set of 285's. Thanks again for all the post. Saves a bunch of trial and error $$$. I also have a set of 3:55 gears Ring and Pinnion that I'm gonna sale. If any one is interested PM me or look for them on the classifides.

 

My next set of tires will be a quintet of E-rated (3700#)+Toyo M55s in the 285 size.

jh