Taking The 285 Plunge

whitesnake01 · August 24, 2007

My stock tires are now worn out and I have been debating back and forth what to do next. My stock rims (aluminum) also look crappy, even if this is a 2005. Some of it was caused by me driving on the Dalton highway last summer, all the way up to the arctic ocean.

So I decided to take the plunge and go with 285s. Since proper fit of them ideally needs 8 inch rims, and that my stock ones look crappy, I opted for new rims as well. I googled around for quite a while until I found a set that I liked. I settled for the Eagle Alloys series 186. For tires, I went with the Michelin LTX M/S 285/75R16, since I've been very happy with them in the past.

To deal with winter problems (salt and sand) as well as occasional bad roads, I opted for a second set of wheels and tires. I went with a set of black steel wheels, 8 inches wide, and a set of Toyo Open Country A/T 285/75R16. This way, I should be able to keep my summer rims nice and clean while getting better traction in the winter. Also, I am not going to worry about if the winter wheels go bad. I basically do not care. I used the same black steel wheel for the Michelin spare.

So now I am waiting for this to get installed. Actually, I am really waiting for a new SmarTire setup to arrive before I go ahead and get the tires mounted. I've used that for 7+ years on my trailer and am now upgrading the whole system to include the truck and all the spares as well. That system monitors pressure and temperature in each tire, continuously. Works great. While I've only had two tires go on the truck, so far, I've had 7 go on the trailer over the years. SmarTire has paid for itself many times over by saving me on trailer repairs. Each time I've been able to safely pull over and replace the tire instead of it flapping around in the back, ripping the side of the trailer.

The next logical question is what to do about reprogramming the truck for the new tire size. I've called around a bit and both Westers (about $495) and Kennedy (about $695) offer decent tow/economy tunes. However, neither of them do anything about offsetting the shift points because they do not want to touch the TCM. My local Chevy dealer can reprogram my truck for $76 and this includes the corresponding TCM change for offsetting the shift points. What would you do? Has anyone out there gone to the dealer first, to get the ECM and TCM changed and then gone with a performance chip so as to benefit from the offset in shift points?

The next thing is getting these tires to fit properly on the truck, which mainly is a clearance issue. I've seen many write about shaving the corner off the bumper with a hack saw. Some have also cranked the torsion bars. When I bought my 2005 2500HD I also had the dealer install their standard Chevy splash guards in the front and in the back. What is your experience with clearance? If they pose a problem, since they are mounted on the inside, have you found other splash guards that work around this problem?

I am hesitant about adjusting the ratio of the front and back too much, since I do not want the tail to be down too much when I tow. Like many of you, I do not like the nose-down look. But I like the ass down less. How have you dealt with this? Is there an easy way to crank up the rear as well, in concert with the front? I am not looking for a big crank up. Just enough to create comfortable clearance.

Thanks for your help,