Time to replace the tires on a '97 2500 CTD 4x4 I bought last year. It currently has BF Goodrich 285/75R16-D on it; I see by the door plate that standard is LT245/75R16-E tires. Am I going to see a noticeable difference in RPM, mileage, etc if I drop back to the 254s?
Also, how big a difference in carrying capacity between the Ds and Es?
Thanks.
Greg

 

I was kinda wondering myself cause I was wanting to put either 265/70s or 285/60s on my truck cause they are all basically the same diameter but I am worried they wont put up with the weight of the CTD

 

Check the load rating of the tires you are buying.
Most 285/75/16-D have as much or more than the same tire in a 245/75/16-E.

: Eddie : 8)

 

yea but at a different preasure... i dont know what the tires should be set at if I go to a different style of tire

 

I've noticed my 315 BFG "D"s have the same weight rating as my 265 OEM Michelins "E"s.

E's max was at 80 psi, D's at 50 psi.

E's didn't bulge much at the sidewall with only 65 psi, D's bulge so bad they look flat with the max 50 psi in them.
That's a lot of sidewall flex over the 30,000 miles I expect to get out of them.

I don't plan on going with D's again for this reason alone.

If you tow heavy, or load your truck down, go with the "E"s, much safer for you and those around you.


phox

 

285/75 Load range d will carry as much as a 265/75 size load range e but the d rated tire will always build more heat because it has a thinner sidewall causeing it to sway and move more with increased weight.I got this from a tire dealer that drove a ctd and said if you tow use an e rated tire.

 

To be accurate a 285-75-16 BFG max weight is 3305 @ 65PSI not 50PSI. It also has a 3 ply sidewall not a 2 ply like OEM tires have...............Pete

 

[quote author=gkainz link=board=5;threadid=22476;start=0#msg210058 date=1068947867]
Time to replace the tires on a '97 2500 CTD 4x4 I bought last year. It currently has BF Goodrich 285/75R16-D on it; I see by the door plate that standard is LT245/75R16-E tires. Am I going to see a noticeable difference in RPM, mileage, etc if I drop back to the 254s?
Also, how big a difference in carrying capacity between the Ds and Es?
Thanks.
Greg
[/quote]

245/75/16's should be around 9.6 x 30.5. 285/75/16's should be around 11.2 x 33. So, there is around 2.5 inches diff. in the height of the tires. You should see a little higher RPM at the same speed going back to the shorter tires. Your speedometer will read right again too. Depends on what your hauling as to the carrying cap. I run D's on my truck because it's rarely loaded to it's limits. I think D-rated tires ride better and do better off road because when you air them down, the sidewalls flex alot better than E's. If I was hauling heavy all the time, and didn't care about airing down and such, I'd go with E's

 

[quote author=Pete Peterson link=board=5;threadid=22476;start=0#msg210787 date=1069122894]
To be accurate a 285-75-16 BFG max weight is 3305 @ 65PSI not 50PSI. It also has a 3 ply sidewall not a 2 ply like OEM tires have...............Pete
[/quote]
Pete's bang on here. I looked at 285 BFG's but they were too wide for the stock rims. I replaced my 245E's with BFG 265D's. Both were rated at 3042 lbs, the E's at 80psi and the D's at 65psi. My guess is that it has to do with the load being distributed over a larger volume of air, hence the difference in pressure. The E's are a 10 ply and the D's are 8 ply.
If you go from 285D's back to 245E's, you'll notice less body roll when turning corners. They might ride a bit rougher. IMO 245's look too small on 4X4's, which is why I changed.

 

I had 265s on my truck when I bought it used but the spare was a 245. I bought the truck for towing and have the 3.55 rear end.

So when I changed to the 245s it made my Auto shift correctly and better low end towing grunt. It also lowered the truck by an inch so it helped with my gooseneck clearance. Much cheaper tire with more types, styles and weight ratings.

 

yea I just ordered a set of 275/75s for mah truck, ill post some pics later

 

...Your speedometer will read right again too...
Unless the previous owner changed the vss gear to correct the speedo to the new tire size.