switch from 265 to 285 tires

What width is the rim? Many stock rims are not wide enough for 265's, much less 285's!
With that said, their are some cases where having a slightly narrow rim is better than wider, like off roading, this protects the rim, along with potentially getting a bead removed at lower psi........ Reality, if loading heavy, you need the correct width rim. I noticed lack of handling with the stock 6.5" rim, vs the aftermarket 7.5" rim with 265's, on my 88 and 96 SW 3500's. I can not in all contagiousness recommend 265's, much less 285's on a stock 6.5" rim, if that is what you have.

Marty

Hi, I do believe the stock wheel to be 6.5

TRIPLE8 wrote:
Hi, I do believe the stock wheel to be 6.5

I won't recommend it because of lack of rim width.
As far as a lift.....you may get away with some trimming of fort bumper,. I had to do this with 265s. 285s trimming and raising torsion bars may work. Rear an add a leaf, least favorite option, a new spring pack that lifts rear an inch or two at also work
IMHO, you.need a 7.5-8" rim for the 265s!

Marty

I had 265 tires on a 7" wheel and that was pretty much all you could do. I know folks put on 285's on the stock wheels, but they pull the sidewalls in a lot and not recommended as Marty said.

My F150 has the 20" wheels that are 8.5" wide and have 275's on them. I could probably go to a 285 or even a 295 at most, but I'm not interested in doing that with this truck.

Without a level or 'lift' you might find 285's might rub on the front when turning lock to lock.. You can usually get away with trimming whatever it's rubbing on if it's plastic. If you start rubbing the fender itself, then you should raise it a bit.

Good luck!

Mitch

Thank you for the replies. I have no problem getting wider rims I was most worried about rubbing. Thank you

OE Dodge Ram wheels fit on your Duramax. The 3rd gen 17" X 8" wheels even accept the GM hubcaps.
In my experience, 285-70-17 rubbed slightly at full lock. But measure your truck. Mine sat up a bit higher than some. If yours is a saggy Dmax, then 265s.
This is not a question we can answer. Measure your clearance.

You can get away with more variation between tire and rim width with taller sidewalls, but the tire you wish to purchase will usually have rim width suggestions for its use.

I need to point out, which I did not do well earlier. What I mentioned doing, is what I did to my 88 and 96 8 lug GM SW 3500 trucks.
As noted, you will have to try it.out, measure etc.
I do not see anyone discouraging you by any means, just be cautious. An FEA may be needed depending on how tires sit, steering after adding taller and wider tires, longer shocks......

Marty

I made that exact change and it screwed up my gearing bad.

ScottG wrote:
I made that exact change and it screwed up my gearing bad.

I was thinking about this too! If one has 4.10s, you go from a 245 size as noted to a 265, you've effectively lowered the ratio to a 3.95. A 285 to a 3.73. If starting at a 3.73...> 3.55 @ 3.42 effective ratio. A gear change @ 1500 per pumpkin if an 8 lug gets pretty pricy.
My 88 with a th400 3.73 gears was noticeably worst. My 96 6.5rd with 4.10s and 5 sp manual imho made it a bit better...still noticed some initial loss of power on take off. A bit better rpm on freeway.

Marty