I am now running 265/75/16s on a 98.0 12v QC/SB with 5 spd and 3.55 gearing. I want to put on taller, but not neccessarily wider tires to reduce my rpms at cruising speed (and for looks). How will this affect how my rig rides and handles? I am looking at 255/85/16s, other suggestions? I've read that taller than that and the spare will not fit up between the frame. What so you folks with taller tires do for spare? Comments and info appreciated.

 

Some conversions here for tire sizes:
265/75/16= 10.4" wide, 31.5" tall.
255/85/16= 10" wide, 33" tall. You only gain about 1.5" overall height.

Taller tires ride slightly better by absorbing bumps better and making small bumps less noticable. They also have more sidewall height, which can effect cornering slightly, especially if you are towing a heavy load. Will you notice 1.5" of extra height? Probably not.

Check the load ratings of the tires you buy. Its more difficult to find load range E tires in larger sizes. If you don't tow heavy loads, you might be able to get away with D rated tires, but I really wouldn't advise it with a diesel. Even with 60 lbs. of air and an empty truck my 265/75/16 E rated front tires bulge a bit.

I don't keep any tires up under my truck. I just store the spare in the bed. Up here in the winter, you don't want to be crawling under the truck for a tire at -30 degrees, the tire winch doesn't work well when its packed with ice and snow, and they rust up making it impossible to remove the tire after a couple years.

Jim

 

I have run the 33" tires and there is a huge differance in cornering and manueverability of these heavy trucks. Once you get used to it you won't even notice it until you go back to smaller tires. The only "E" range tires I can find in these sizes are the Truxxus Radials and they are great tires made for rock crawling but you won't get much mileage out of a set. My last ones went 15,000 and they were bald by then. If anyone knows of others I am always looking, I hate these little things but need the weight rating.

 

I have been running the 255/85s for 2 years now, and will for as long as they are available. There is a little sway, but once you get used to it the truck actually handles better, IMO. And with such a heavy truck, it is nice to have a tire that will dig until it can get a grip, with 285s I have been stuck on wet grass in 2wd.

 

Toyo make a few tires in a 285/75 E rating... Never heard anything bad about them either.

 

Taller and wider tires

They do affect your ride, yes, but i think that they affect the suspension, and on the front of these trucks, the toe and camber more than anything else, I think the ride quality comes from the number of plies or load ranges that these tires have, naturally the more plies u have the stiffer the ride is gonna be, My truck has 285's and it runs great with them, but the suspension is tweaked for them with the skyjacker kit, I have not had a problem with my suspension.. Stock, well they came with 265's out of the factory if im not mistaken, so one size up shouldnt matter, but if you go to 305's or 315's, then u might have some more issues, as to wear on the drivetrain, a slower truck, and so forth....

Tx

 

I run 285/75/16 on mine I hardly noticed any difference in the handling. they seem to hold up pretty good too. I also mounted one as a spare, and it fits inside the frame, no prob.

 

I agree. 255/85's fit my bill as I don't really need load range E tires. As for the spare, I'm using the stock size. If - check that, when - I get a flat I'll put the smaller dia stock tire up front as not to damage the limited slip rear. As I think about it, I better go out and make sure the spare has air....

 

BFG makes their mud terrains in a 255/85-16 and "E" load rating. Seems BFG are a love or hate brand, but I swear by them and have 30+k on my 37" mudders and better than 10k left. Availability is nice, and BFG is just about everywhere!