OK...I blew a tire...holiday weekend...will it hurt to put about 100 miles on the vehicle using the full size spare...trailering a 5000 pound boat too..

I am worried more about the AWD system and possibly causing a problem due to 3 tires being one diameter and the spare a different.

Please let me know your thoughts. I know there are a lot of you out there with the working knowledge of the transmission and transfer case.

Vehicle is a 2014 R/T AWD.

 

100 miles? Go home.
If its a full size spare, how can it be different than what your other tires are?
Full size means just that. Its a full size match to your other tires.

 

Because they give you an 18" full size spare even if you have 20" wheels. But I think I looked into it and the overall diameters are pretty close. Maybe you saw a difference when you handled the tire?

 

And I didn't see any warning in the manual about not driving on it. If you'r towing, I assume the spare has an adequate weight rating.

 

tire diameter is exactly the same thats the important part you can drive for life on it.

 

More likely, it's a "full size temporary spare" and not a "matched full size"

Full-size temporary spare tires and wheels match the vehicle's original tire dimensions, but typically feature lighter-weight construction and a shallower tread depth to reduce vehicle weight to improve fuel economy and make the spare easier to install. While most of today's vehicles are originally equipped with alloy wheels, full-size temporary spares are typically mounted on steel wheels and should be used only as spares.

That said, there's a reason that tow groups come with a full size spare. You'll be fine on it. Just be mindful of the shallower tread depth if you encounter water and take it easy as the tire isn't as heavy duty as the others.

 

I am more concerned about damaging the AWD system. A tire that is at 8/32 versus a new one at 10/32 will complete 4 more revolutions a mile. Hence will this screw up the AWD. And if so do I have to replace all 4 tires or just the front 2?

 

Mine is a regular old Kumho P245/65 18 M&S. I have the tow package.

 

That's assuming you only drive in a perfectly straight line, never making any turns.

 

My full size spare is OEM 18" Goodyear that is a regular production tire. The difference of a few lbs of air pressure in a tire will make more diameter difference than wear. Keep you tires at 38lbs and you spare at 32 lbs and your tires could have 0/32" and they will still be a larger circumference.