thinking about going to this size tire, everyone says they fit without lift, but...... at what cost, what do yall think? Currently 285's

 

I just went from 315s down to 285s. The 315s were nice but I just wanted to go to a smaller tire. You may get a small amount of rub at full lock or if you hit a big bump. If you go offroad alot then you may want a leveling kit. I lost 1 mpg going from 265s to 315s. They will rob you of some power too but if you run a fueling box it's no problem. They do look good....
Before w/ H2 rims/315s

After w/ PowerWagon rims/285s

 

My dealer put the 2" leveling lift on and I have had no problems. The tires did rub at times before the lift.

Good luck;

Jim

 

Dzilla

Did you get your mileage back?

Jamie

 

I got about .5mpg back going to the 285s, I think. I did the tone ring mod and switched the tires over right about the time they switched to the winter blend of fuel. Normally I lose over 1 mpg with the winter fuel but my mileage has stayed a consistant 16-17 so one or the other or both did help. Hard to say which one it was though.
Looking at my pictures side by side, I would have to say it looked better with the 315s but I'm sticking with the 285s.......

 

I looked a a truck with the 315's on OEM wheels, they just looked too wide for the wheel, the tire tread was rounded when it would normally be flat or pretty close to it. I ended up going 305/65/17 and I'm very happy with them.

 

I put BFG AT 315/70R17's on the stock rims and I don't have any rubbing at all. I think that tire size with aftermarket rims are a cause of concern due to improper back spacing. I'm going off-roading in a few weeks and I'll find out then.

 

we've got 35K on the wifes 315's ...

nice and flat across the top ... run 50 psi front and 25 psi rear (empty)

rotate every 5k

looks like 45 to 50k life expectancy

we don't tow very much and then it's pretty light

 

I am also going with the 305's, 315's look good but I pull a trailer from time to time.I think lveling kit with 305's looks good, farm truck look,but lift is last,Dynatrac hubs first. 06reg cab 4x4CTD6spd 3.73

 

I installed 5 315's two weeks ago. So far I like them. I have no lift and at full lock they do touch the track bar but I intend to modify the steering locks to prevent that. If I back off less then a 1/4 turn on the steering wheel there is no rubbing.
Did lose a bit of grunt at low RPM's, but nothing to worry about. Once the turbo winds up I am not sure if I can feel any difference. According to the overhead I may have lost at the most 1 mpg, but to compensate, I enjoy the lower RPM's at 70 mph.
Am still experimenting with tire pressures and keep on taking more air out. Presently at 38 rear and 40 front and it looks like I need to bleed even more out especially on the rears.

 

I probably lost 2 mpg after going from 285's to 315's. I do a lot of city stop and go driving which is not the type of driving that will benefit from a larger tire. It's still worth the improved looks IMHO. Oh yeah, I added a quad xzt which gave me my accelleration back, but didn't really improve the mileage. I would imaging that the mileage would be excellent if you did a lot of highway driving in little/no traffic. I encounter traffic everywhere I go. If you don't care that much about the look of a larger tire, stick with the 285's.

 

Heres the thing though, how many of you people that had 315s put on your truck get the speedo recalibrated? In my opinion, and messing with some gassers, if you go to larger tires, and run mainly on the highway, your cruisng speed will be down. This, in turn, saves fuel money. When you put bigger tires on a truck, it will throw off the speedo, therefore throwing off the odometer, and tell you that you have gone more miles, when you really havent.

I'm actually thinking of going to 315s once these 2 sets of bfs rugged trails wear out(the set that is on the truck now has 57000 miles on them, and quite a bit of tread left, and the other spare set I've got has unknown mileage-got them free from an off-road shop at home, and they have just as much, if not more, tread on them).

 

Yes the RPMs are down on the hwy but the extra rolling mass still causes you to lose mpg. Actually the hwy mileage doesn't change much, if at all, but the in town mileage suffers...

 

It says you go LESS miles than you actually have, because the speedometer will be slower. I get around 17mpg highway with 37x12.5's and a huge cow bumper

 

I gained about 1-2 mpg when I put 35X12.50s on my truck. From what I've found most of the people I know with autos suffer when they put them on, but the 6 speed trucks improve.