Rear Tire Spare for SS Question

[tony1]

the 275/40/20 is:

Diameter- 28.7
Circumference- 90.0
Revs/mile- 704.0

the 245/45/20 is:

Diameter- 28.7
Circumference- 90.1
Revs/mile- 703.0

which are our Stock tires. Question is if we use one of the front tires for a spare on one of the rears will this slight difference damage the posi/differencial?? In one mile we are one complete rotation apart.

[Rock-It Man]

Are you serious? When you are on the highway, you are rarely driving in a straight line for a mile, so the diff is working all the time.

BTW, I put a full size front in my trunk today, along with a lug wrench, scissor jack and wheel chocks.

There's not much room left over for luggage. Basically, the wheel blocks access to what little volume is left over.

But, now I'm ready for a road trip!

[clg_98ta]

Originally Posted by tony1

the 275/40/20 is:

Diameter- 28.7
Circumference- 90.0
Revs/mile- 704.0

the 245/45/20 is:

Diameter- 28.7
Circumference- 90.1
Revs/mile- 703.0

which are our Stock tires. Question is if we use one of the front tires for a spare on one of the rears will this slight difference damage the posi/differencial?? In one mile we are one complete rotation apart.

No - the 0.11 % difference will not hurt anything. You probably have more variance than that from a 2 psi difference in pressure between left and right.