Well decided its time for new shoes so roasted old ones one last time and went to Discount Tire as usual. Worked out the deal and left for them to install. Get back and ask guy how much pressure hes putting in...says 80. Sure enough they put on E rated when old ones were D.

Come to find out tire manufacturers are not making D rated in 285's anymore from what he said. All E now. Told him I didnt want E cause they ride like tanks so he checked and there was 1 set left in the whole country! Grabbed em up for sure.

My question is I dont know why anyone wouldnt want D's over E's anyday? 285 D has more capacity or the same (cant remember right of hand) as the stocker 245's or the 265's E rated. Thats why I went up to 285's so I could drop down rating wise and TBH I wouldnt have it any other way. I LOVE em. I tow without any problems and the traction is unbelievable. He let me keep these E's on till others come in since they were already mounted and man they SUCK. They slip all the time, they feel unstable on highway (walking alot), and ride like they are square. From a stop I guaruntee I could roast these off the rims. I could NEVER spin the D's from a stop. They were sticky as hell.

Anyways just thought Id share this with any others out there running D's...although Im prolly the only one :D

Well decided its time for new shoes so roasted old ones one last time and went to Discount Tire as usual. Worked out the deal and left for them to install. Get back and ask guy how much pressure hes putting in...says 80. Sure enough they put on E rated when old ones were D.

Come to find out tire manufacturers are not making D rated in 285's anymore from what he said. All E now. Told him I didnt want E cause they ride like tanks so he checked and there was 1 set left in the whole country! Grabbed em up for sure.

My question is I dont know why anyone wouldnt want D's over E's anyday? 285 D has more capacity or the same (cant remember right of hand) as the stocker 245's or the 265's E rated. Thats why I went up to 285's so I could drop down rating wise and TBH I wouldnt have it any other way. I LOVE em. I tow without any problems and the traction is unbelievable. He let me keep these E's on till others come in since they were already mounted and man they SUCK. They slip all the time, they feel unstable on highway (walking alot), and ride like they are square. From a stop I guaruntee I could roast these off the rims. I could NEVER spin the D's from a stop. They were sticky as hell.

Anyways just thought Id share this with any others out there running D's...although Im prolly the only one :D
I totally agree! I went with the 305/65 17 BFG E's, I hate em! They are perfect size, just don't last and no traction:mad: Tomorrow morning I get the new 315's again. I think I'll just stay with them from now on.

Why don't you drop the tire pressure down? I run mine at 40 or maybe 50 psi. It softens them up alot. I could care less what letter is on the side of the tire, it's the actual capacity that counts. I have 305-65-17 E, and there capacity sucks, too low for me. I will be going with some sort of Nitto 285 E next. They are good for 3750lbs. That is what I am talking 'bout, I need all I can get.

Thats my capacity now. And they are at 55 psi now. Suck still. Maybe Im spoiled by the 285's and D rating but these things are like square wheels.

I'm running LTX A2 Michelin's in the 285/75/16E and the psi at 60. The tire dealer put 80 psi in the rear and 55 in the front and it rode like hell. Since I set them at 60 psi they ride great. I went with the E's over the D's because the E rated had a higher capacity by 400lbs. However running a lower psi drops the weight capacity of the tire. If you increase the tire size then usually a 305 D may have the same if not more load capactiy than a 285 E because of the volume of air in the tire depending on the manufacture. Also the rim size effects the load rating due the loss of sidewall height, such as a 16" tire the same size as a 17" will have a higher load rating even if they are both E's or D's and the 18" and 20" tires lose even more load cacity because of the sidewall loss. I have friends that run the BFG 285/75/16 D that wore out in 20k then switched to the E's and have 40k plus on them. I learned from my stock tires that 80 psi was bad for everyday driving with no load but I did manage 35k out of them. I raise the psi back to 80psi on the rear when towing heavy or put a heavy load in the bed. All the E tires had more capacity than the D's in all the tires I looked at before I bought the LTX's.

Finally!! Just finished and drove to my shop and I LOVE IT!! What a difference. Feels like I'm riding on cloud and not a covered wagon:eek: Got new 315/70 17's. I did like the looks of the 305's but the wear factor and HORRIBLE ride killed me. I wish BFG made the 305/65 17 in load range D. I took some pics of the two mounted on rims side by side. I forgot how tall the 315's were...lol

Look good bud :thumb:

Finally!! Just finished and drove to my shop and I LOVE IT!! What a difference. Feels like I'm riding on cloud and not a covered wagon:eek: Got new 315/70 17's. I did like the looks of the 305's but the wear factor and HORRIBLE ride killed me. I wish BFG made the 305/65 17 in load range D. I took some pics of the two mounted on rims side by side. I forgot how tall the 315's were...lol
That looks nice! Are you just running a leveling kit on that or the t-bars cranked up or do you have a lift?

I just bought some Hankook MT 285/70 R17 in load range D. they ride waaaaay better than the stock tires did. they had like three sets at Town Fair Tire, but that's in New England. I went back to have re-torque the lug nuts and they had even more, guy said it's a popular seller. :confuzeld

That looks nice! Are you just running a leveling kit on that or the t-bars cranked up or do you have a lift?

Right now I have the Max CamII keys. A little trimming and tied back emergency brake cable.

If you pump any tire up to 70-80 psi running empty, the centers will wear fast, and give a harsh ride. In my case I need th E's as I pull a heavy fiver on occasion, but I air down the rears to 40 - 45psi when empty. On my 02' I had a smaller trailer and had run two sets the D range Nittos that wore quickly, even when airing down when empty. I now have some E rated Nittos on it, and for whatever reson the E's are wearing much better than the D's did. I never noticed any difference in ride between the two ratings. My 09' is riding on E rated Hankooks, and I like them even better than the Nittos so far.

there are tons of 8 ply 285/75r16's available
bfg at
nitto terra grappler
dunlop mud rover
kuhmo road venture
michelin ltx m+s
mastercraft courser at-2
goodyear silent armor

there are tons of 8 ply 285/75r16's available
bfg at
nitto terra grappler
dunlop mud rover
kuhmo road venture
michelin ltx m+s
mastercraft courser at-2
goodyear silent armor


Cooper SST
Toyo A/T

I believe the Dick Cepek FC II's are as well.

Right now I am running BFG AT 285/75/16 D's at 50 psi all the way around and can't omplain about the ride...
How does eveyone fix their speedo's though?
I took mine to the stealership to have the ECM "re-calibrated" or whatever, to the new tire size and they tech said that their GM Tech2 code reader/programmer would not work. He tried it several times while I was standing there and it said "unable to calibrate" ????
Anyone else had this problem? - What was the solution?

Well decided its time for new shoes so roasted old ones one last time and went to Discount Tire as usual. Worked out the deal and left for them to install. Get back and ask guy how much pressure hes putting in...says 80. Sure enough they put on E rated when old ones were D.

Come to find out tire manufacturers are not making D rated in 285's anymore from what he said. All E now. Told him I didnt want E cause they ride like tanks so he checked and there was 1 set left in the whole country! Grabbed em up for sure.

My question is I dont know why anyone wouldnt want D's over E's anyday? 285 D has more capacity or the same (cant remember right of hand) as the stocker 245's or the 265's E rated. Thats why I went up to 285's so I could drop down rating wise and TBH I wouldnt have it any other way. I LOVE em. I tow without any problems and the traction is unbelievable. He let me keep these E's on till others come in since they were already mounted and man they SUCK. They slip all the time, they feel unstable on highway (walking alot), and ride like they are square. From a stop I guaruntee I could roast these off the rims. I could NEVER spin the D's from a stop. They were sticky as hell.

Anyways just thought Id share this with any others out there running D's...although Im prolly the only one :D

LOL!!! I have the exact opposite view! :D

I just had a set of Toyo Open Country 285/70R17s put on, and gladly paid the extra $$ for E's over D's. It's not that E's are really more expensive, it's just they didn't make an E in the less expensive brand.

The reason I insist on E's is because they are a much sturdier tire and squish down a lot less. With 285/75R16 Ds set at 50 PSI, my 2002 had 7 3/4" clearance under the read diff. With 285/70R17 Es set at 60 PSI(which is .13" smaller in diameter), my 2009 has 8 1/8" clearance under the rear diff. If I were to try and run D's at 60 PSI, the centers would wear out very fast.

Also, my truck rides better with the Toyo 285s than it did with the stock 265s. Then again, I run Bilstein shocks. I suppose if I really wanted a cushy ride, rather than take the hit in fuel mileage and ground clearance that comes with D rated tires, I'd just get Rancho RS 9000 adjustable shocks. I ran those on my 2002 for 75,000 miles (when I was rear ended and the truck totalled) and they worked great. The difference in ride was very noticable as I adjusted the shocks. I coud go form squishy to firm very easily.

Right now I am running BFG AT 285/75/16 D's at 50 psi all the way around and can't omplain about the ride...
How does eveyone fix their speedo's though?
I took mine to the stealership to have the ECM "re-calibrated" or whatever, to the new tire size and they tech said that their GM Tech2 code reader/programmer would not work. He tried it several times while I was standing there and it said "unable to calibrate" ????
Anyone else had this problem? - What was the solution?

That is correct, the dealer cannot correct the speedo. You need to have your PCM reprogrammed. John Kennedy (www.kennedydiesel.com (http://www.kennedydiesel.com)) offers this service and his tunes work great.

BTW, you do have an LB7 in your 2003 unless someone changed the engine, which is unlikely.

I found a guy that can do the reprogramming nearby, but he charges $250 whether he gives you more horsepower, or just changes the tire size. I am afraid to get more horsepower because of a small trans. leak I have found, and don't want to pay that much for just a tire size re-calibration.

I didn't know how to tell the difference in the motors, that's why I put the (?) in my sig. If I type in my VIN on a parts search online - the truck shows up as a Chevrolet (even on my Insurance cards) but it is a GMC...?

The LB7 was the engine 2001 to 2004.5

The LLY was the engine from 2004.5 to 2006

The LBZ was the engine form 2006 to 2007.5

The LMM is the engine form 2007.5 and up

Given these engines easily last 300-400,000 miles unless thrashed VERY hard, it is likely you have the original engine.

BTW, beef the tranny BEFORE you add any power.

how does one go about doing that?

The best bet is to have a Suncoast Stage IV and one of their convertors installed in your tranny. Or just get the whole tranny from Suncoast. Do a search on the topic and you'll find lots of info. It's very easy to fry the Alli when adding power to the Dmax.