afp1
09-01-2009, 01:45 AM
I am the author of the TIRE FAQ for GM HDs (http://dieselplace.com/forum/showthread.php?t=91242) thread. That thread is based on my experiences with my 2002 DMax, on which I ran everything from 265/75R16s to 315/75R16s and went from cranking T-bars to two different lift kits.
I learned the lessons on my 2002 and applied them to my 2009. I am running Toyo Open Country 285/70R17s on the factory 7.5" wide wheels. I just had them put on two days ago. I have my t-bars cranked about 1.5" and am not getting any rubbing. However, I only have about 1/4" clearance between the tire and the aft portion of the front wheel wheel with the tire turned to its least favorable position. Because of that I will be working on the front fender metal. It looks like I can get a full inch of clearance with just a little work. Here are some pics:
Full side view:
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/DriverSide.jpg
Wheels straight ahead:
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire1.jpg
Wheels turned approx 45 degrees (aft part of front wheel well):
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire2.jpg
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire3.jpg
Wheels turned approx 45 degrees (forward part of front wheel well)
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire4.jpg
Reasons I think it isn't rubbing with so little clearance at the aft portion of the wheel well:
- I'm using the factory wheel with its correct backspacing for these trucks
- I'm running Bilstein shocks
- With 1.5" of T-Bar crank, the wheel well is mostly vertical where the tire is closest to it, which means the tire isn't getting any closer to the wheel well as it travels up and down. I had one guy get in the diver's seat and another jump up and down on the driver's side nerf bar so I could watch all this, and to be honest, I was suprised we couldn't get it to rub. Realize that if I were hit a hard enough bump with the tires turned to their least favorable position, I'd expect to get some rubbing--not sure it would really hurt anything. Regardless, I'm going to work on the fenders. It doesn't look like it will be too hard to bend a little metal, reposition the inner fender liner, and gain about an inch of clearance.
My speedo went from reading about 1 mph slow at 70 to about 1 mph fast at 70. The numbers calculate to a 3.36% difference between the two tire sizes. The truck doesn't seem to accelerate much differently, though the turbo seems to load a bit sooner which improves throttle response a bit. Realize I am using my seat-of-the-pants feel for this evaluation, and SOTP is THE most unreliable indicator there is.
The truck rides as smoothly as it did stock, the Toyos seem a little quieter than the stock tires, and the truck does corner better.
I learned the lessons on my 2002 and applied them to my 2009. I am running Toyo Open Country 285/70R17s on the factory 7.5" wide wheels. I just had them put on two days ago. I have my t-bars cranked about 1.5" and am not getting any rubbing. However, I only have about 1/4" clearance between the tire and the aft portion of the front wheel wheel with the tire turned to its least favorable position. Because of that I will be working on the front fender metal. It looks like I can get a full inch of clearance with just a little work. Here are some pics:
Full side view:
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/DriverSide.jpg
Wheels straight ahead:
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire1.jpg
Wheels turned approx 45 degrees (aft part of front wheel well):
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire2.jpg
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire3.jpg
Wheels turned approx 45 degrees (forward part of front wheel well)
http://i232.photobucket.com/albums/ee195/afp416/2009%20DMax/FrontTire4.jpg
Reasons I think it isn't rubbing with so little clearance at the aft portion of the wheel well:
- I'm using the factory wheel with its correct backspacing for these trucks
- I'm running Bilstein shocks
- With 1.5" of T-Bar crank, the wheel well is mostly vertical where the tire is closest to it, which means the tire isn't getting any closer to the wheel well as it travels up and down. I had one guy get in the diver's seat and another jump up and down on the driver's side nerf bar so I could watch all this, and to be honest, I was suprised we couldn't get it to rub. Realize that if I were hit a hard enough bump with the tires turned to their least favorable position, I'd expect to get some rubbing--not sure it would really hurt anything. Regardless, I'm going to work on the fenders. It doesn't look like it will be too hard to bend a little metal, reposition the inner fender liner, and gain about an inch of clearance.
My speedo went from reading about 1 mph slow at 70 to about 1 mph fast at 70. The numbers calculate to a 3.36% difference between the two tire sizes. The truck doesn't seem to accelerate much differently, though the turbo seems to load a bit sooner which improves throttle response a bit. Realize I am using my seat-of-the-pants feel for this evaluation, and SOTP is THE most unreliable indicator there is.
The truck rides as smoothly as it did stock, the Toyos seem a little quieter than the stock tires, and the truck does corner better.