NJMurvin

I like the looks of the 315s. I don't do any real offroading and I don't deal with snow or ice. I just like the looks. How much taller do they make the truck? I'm planning to order a 3500 SRW short bed Quad Cab and I'd like to be sure it'd still fit in the garage with these (no lowering kit).

Thanks,
Neil

Mike67RS

It should raise it about 1½". It will fit a standard opening of 7' if your garage door does not hang below the opening. I have 315's and a leveling kit...no problems here.

diirk

Dang,
Did you have to butter up the sides to get that in there?

moterhead

Go here:

http://www.csgnetwork.com/tireinfo4calc.html

If you plug in 265/70/17 on one side and 315/70/17 on the other, the diameters come up

265 = 31.61
315 = 34.36

The difference in diameters is 2.75. Divide this by 2 to get the radius gives you 1.375. This is how much the truck will be raised.

The calculator also gives you revolutions per mile

265 = 638.1
315 = 586.93

The percentage difference is 8%. This is how much slow your speedo and odometer will read as well as how much your "effective" rear axle ratio will be reduced. I.E. your 3.73 be act like its a 3.43 and a 4.10 will act like a 3.77.

All these calculations are based on a generic tire. Differences between specific brands of these sizes will likely vary. YMMV!

diirk

moterhead: Great info.

In general, it seems many folks are going with the 315/70-17 BFG All Terrain. Diameter is 34.5" and RPM is 601.
They were on sale at a few place, but I think the price has started creeping back up. Best price I found today was $150 at Discount Tire.

Mike67RS

Naaahhh...I've got at least 2" on every side...Plenty of room.

rossn2

ggg

rossn2

dang computer....

THE BFG 31570R17 revolutions per mile is 601 at 45 mph - Direct from BFG Website and I called Tech Line to confirm.

Had Dealer reset mine last week when I installed the tires and no problems with speedo so far. Getting the darn things balanced correctly is another story...

look at my photo gallery for pics...

WOW tire rack price jumped from $123 last week to $184 today! Guess to many DODGE owners are buying them!

Mike67RS

Rossn2...America's Tire Company balanced mine and they turned out perfect. They threw in lifetime balance for $20. If you got one around your place, try them.

rossn2

Nope, don't have one. After going through AAFEES and GoodYear, Discount Tire has a "RIDE MATCH" machine that worked. Of course it cost AAFESS $100 for all four....and that's when we found out that one of the tires is bad and can't be balanced. So later today or tomorrow new tire arrives and DT said they'll mount and balance for free for me....

NDanecker

Will going to the larger 315 tire effect MPG?

rossn2

Yes, it should raise it slightly...
At 65mph I'm now turning around 1500-1600 rpms. At 70mph is right at 1900 rpms..where before at 70mph I was at 2100-2200 rpms.

300 SDL

rossn2

For a lifetime balance use Equal. Be certain to use the available filter valves.