Spare tire and rim

[Durango1]

So we got word our 2018 3500 Ram Chassis Cab will be delivered the second week of March. During the order process I discovered that while our truck will have the LT275/70R18E BSW On/Off Road Tire (TCM order code) the spare tire option from Ram would be a 17" tire! (And a 350.00 option!)

So I said fine, we'll just order a trie and a rim from a tire place. Now my question is does anyone know what manufacturer/tread style for the comes on the LT275/70R18E On/Off Road Tire for the 3500 Ram trucks? (My dealer is pretty clueless)

Or is it even all that important to match up exactly? Can anyone help a tire newby out here?

Steve

 

[PJorgen]

What is definitely important is that the spare be the same diameter as the other tires, especially if the truck is 4WD. If your tires are different diameters (and therefore different circumferences) they will be rotating at different speeds. That makes your differential work harder and will burn it up in the long run.

If the truck is 2WD drive you can always put the spare on the front and move a good tire to the rear, assuming you have a rear flat. That will mess up the handling temporarily but won't damage the vehicle.

However (there's always a however) if you're doing serious off-roading, having a different style of tire on one corner can cause differences in traction which can be a problem. At least that's what the off-road guys say, I've never done it myself.

FWIW - I've got 18" wheels and a 17" spare on my 2012 2500HD 4WD. They are the same diameter, but I've never had to use the spare.

 

[klahanie]

Steve, I can't answer your question but natch will comment anyway.

1) IMO if you are trying to match the tire you may as well match the rim. Then the set can be included in regular tire/wheel rotations rather than be relegated to spare status only (you'll hate having an odd rim on for driving). For a second spare, I bought an extra oem rim and mounted tire for $100 CAD delivered - was a factory spare take off, sold backdoor by an aftermarket tire shop thru craigslist. That was a steel rim with the same oem tire I had. It worked as needed for a few remote trips. Later I bought 2 AL rims off ebay that match my truck - again takeoffs - before I replaced all the rubber with different tires. Now I have 6 wheel sets, all usable for rotation. And this helps justify their cost

2) This may sound dumb but check that you have a jack and lug wrench included with the delivered truck. These may only come with the optional spare tire - after all with no spare tire ordered, you'd have nothing to change out with...

 

[pvstoy]

Hi Steve,

Like what PJorgen says... you can have 18" tires and a 17" spare. But you need to have the 17 inch tire specs match the diameter & revs per mile. The 17 inch can be narrower. I'm sure you have the limited slip in the rear, so you need the diameters to match.

If I paid extra for the tire selection offered by Dodge why would they not have the spare to match? If the 17 inch spare does not match the diameter (revs per mile) then press hard to have the dealer change out the spare to match.

Worst case you can sell the spare, pick up matching rim and tire. But first check the space under the truck where the spare lives to see if a full size fits. Though you are getting a flatbed built they could make it fit.

 

[CamperCamper]

It is fairly easy to find a rim to match the OEM wheels that come with your truck. Somebody is always taking wheels off a brand new truck to get something “better”. Use a Craigslist search tool to search the entire country. You will find a dealer’s parts department that is selling the take offs that the sales department is sending their way. You will find a brand new rim for half the cost of new. Wait until your truck comes in to buy your fifth tire because the manufacturers are constantly changing brands! This is what I did on my Tundra and I do a five tire rotation every 5k. If you get a flat, you have a perfectly matched and worn tire to drop in with the other 3 good ones on the truck. If the flat is able to be repaired, it goes right back into the rotation.

 

[klahanie]

I'll add that a take off FCA factory rim will be DOT approved, correctly load rated (perhaps 3500lbs) and hub centric, if applicable on the 2/3500s. Load rating may not be as big a concern for a steel rim but it might be difficult to find an aftermarket alloy rim with that spec. Just make sure it's not from a wreck !


If your plan for the spare is emerg use only then the above matters less. No reason to think the optional 17" rim size and tire size wouldn't work for such use, esp when placed on the front axle. And you might also find cheap set for sale.

EDIT to get correct mfr name !