2004 6.0l cc. I have a chance to pick up some 17" rims/tires with adapters cheap. The tires are cooper discoverer atr 285/70/17. My original tires are E rated, these are D rated, but when I look at Coopers web site it listed both tires with the same load capacity. So does a lower profile D rated tire equal a taller E rated tire?

 

The load range has nothing to do with the height. It just tells you how many plies the tire has. E = 10 ply D = 8 ply.

 

It would be safer to stay with the E rated tires since that is what the truck comes with from the factory. Not saying that the D rated tires will explode during everyday driving, but I would think twice about hooking up to a trailer or putting a heavy load in the bed with the D rated tires.
Hope this helps,
Drew

 

when i bought my 05 it had load range c tires on it. the previous owner must not have known the difference.

 

Not true anymore. Most tires these days will have 4 to 6 actual plies in the tread, even the load range E tires. Until recently those tires were 10 ply "rated", even though there weren't that many plies. The ply rating has all but disapeared the days, replaced with new numerical ratings.

The last tires I saw with actual ply based ratings were bias ply tires that we used to carry at the shop for customers that still insited on them, that was years ago. There are a few companies that still make them. You wouldn't want to use them on a Super Duty.

 

I think load E tires are required and they are not the same as D rated.

 

D rated is OK for normal driving. E rated can have as little as 2 sidewall plies and 4 tread plies. It's about strength, thickness, amount of cords, placing, carcass strength, quality of steel, etc. It is an overall stength rating and Es will have thier most strength at 80 PSI.

 

same with mine. I think the dealer put c rated on. they were like new. now the fronts are less then 50% (3000miles). Corning sucked and they barked loud. now i have E rated and it drives like a car. well no more handling problems.

 

Wow C rated tires on a Super Duty? It really wasn't all that super with those C rated tires on there. Your saying a dealer put them on? They have to safety the truck for you, they obviously didn't do that if there was c rated tires on that heavy of a truck.

 

it was a small dealler and it was the only non 1/2ton on the lot i dont think they knew anything about what tires should be on it. I didnt.

 

My 06' F-350 came with the 18" E rated Contis (almost worn out),,,but rather sucked after the first year for plowing (suck brand new for mud),,,New 18" tires are big $,,and at the time the,,,2 yrs ago,,were not that many choices,,,I purchased a set of 17" 07' F-250 wheels (takeoffs on Ebay) then a set of 285/70/17" Hankook RT03 MT tires D rated at 3195 lbs,,instead of the 275/70/18" E rated Contis at like 3595 (approx)lbs, both tires 33" tall,,,Awsome traction with the Hankooks,,,not quite as stable as the Contis,,but not a problem so far, pulling trailers and plowing,,,I would say go for it,,,just watch your max weight rating!

 

Going with an E range tire will also get you more life out of the tire. The thicker sidewalls are meant to withstand the weight of a super duty and will not where down as fast. My truck has 53k on it and I am positive that these load range c's are the second set on this truck because of the fact that they are c range and BFG AT TA KO's don't come stock on super duties. Two of my tires are just about done which is pretty pathetic. Within the next month I'll be purchasing some Hankook Dynapro ATm RF10 295/70-17 E tires and I can't wait. Plus I am a true blue hater of BFG. They are cheaply made and you have to chase the weights when you balance them.

 

Don't use wheel adapters.