I just bought my first new Dodge Ram 2500 Cummins, love the truck. I was looking it over and noticed that the spare tire is a "Firestone Transforce Ht" and the tires on the truck are "Fiestone Transforce AT" I just assumed this was a mistake and told my dealer I would like all tires the same. Well for $143 I could have all same. My truck listed for over $57,000 and a thing like this just doesn"t sit well. If I have to use the spare, I don't want 3 tires the same and one different on my truck. Try and go to a tire dealer and buy 3 tires of one tread and 1 of a different tread and have them installed. I don't think so. I'm going to take my spare tire off and put a used one on. Shorty there will be a ad on Craigslist for 1 new take off "Firestone Transforce HT" tire or a add for wanted 3 Firestone Transforce HT tires

 

Sounds like you're in at least better shape than us 1500 guys. I'm not sure about the newer models, but my 2009 has what basically equates to a truck sized donut. The rest of the wheels were all 20" Goodyear Wranglers (HPs I think), but the spare is a 17" no name "Temporary Use Only."

Speaking of which your post reminds me that I need to get that one and the wife's 2004 donut replaced soon. Both have seen quite a bit of use and they've never been replaced or balanced.

 

Not too unusual that the spare is a different type of tire on a different rim - even in trucks. Although on the 2009's with the 17's I did get a spare tire that matched the other 4. Doesn't match any more though since I replaced the stock tires and didn't replace the still good spare to match.

 

I believe the issue is that the 20" wheels have 33" tires and 33s won't fit in the spare tire mounting spot. So even if you buy an exact replica of your 33s you still won't be able to mount it there. My '09 SLT with the 17" wheels had the exact spare tire as the running ones.

Before you go out and buy a 33", try one of yours and see if it will fit.

 

Yes a stock sized 20" rim and tire will fit in the spare carrier. I have one on my truck. I quickly removed that donut "tire"

 

I guess Chrysler is being really cheap then!

 

Yeah, out of sight, out of ind approach. Kinda sneaky unless there's an unknown reason?

On my 2008, which has a different designed frame, I have a full size and same style tire for my spare that came with my truck when new. Suckyear HP's. When I changed to Coopers, I kept the stock spare tire.

I wonder if Chrysler went to the donut style spare for extra clearance with dual exhaust exit? I know 3rd Gen guys who install dual exhaust exit catbacks run really close to the spare tire!

ONE THING I do want to say, and I thought this thread was about.... Check your spare tire pressure! I don't know if the 4th Genners have TPMS on their spare tire or not, but there isn't anything on mine, so the tire can go flat and leave someone stranded. It's something people dont think about until it's too late.

 

Hope none of you guys have a LSD rear diff because if you would ever have a flat on the rear and have to use the smaller sized spare the rear diff is going to self destruct.

 

Bull - its an LSD which is a half a step above an open diff. The clutch will slip to accomidate. Even a dog clutch locker won't "self destruct" from a slightly smaller tire on one side, it'll just ratchet a lot.

 

Go ahead and try it and then report back as to how much it cost you to rebuild the rear diff. Different size tires will cause the rear axles to rotate at different speeds and that will really **** off the gears.

LMK how it comes out for you.