Odd size spare..... ok to use?

[Art_in_CO]

Picked up a 2019 1500 Laramie last week. The mounted tires are the correct original size - 275/65-18. But the spare is a size that's not even available anymore - 245/70-18.

An online tire calculator shows the 275/65-18 at 629 revs/mile and the 245/70-18 at 641 revs/mile. That's a difference of 1.87%.

Would it be ok to use that odd size spare if necessary or should I replace the spare with a correct size?

Thanks.

 

[tidefan1967]

You probably wouldn’t notice a difference on the front since it’s so close in size but in the back I wouldn’t run it over 55 maybe if you have the limited slip rearend. If you have the open rear I wouldn’t worry about it.

 

[audiophile]

You probably wouldn’t notice a difference on the front since it’s so close in size but in the back I wouldn’t run it over 55 maybe if you have the limited slip rearend. If you have the open rear I wouldn’t worry about it.

I concur. Best would be find a matching spare.

 

[Dodge 1500 4X4]

Yes, the spare should be the same size as the mounted tires.

 

[GTyankee]

I am not sure about that

i have 20" on my Ram
The temporary spare is not the same

17" STEEL SPARE WHEEL
FULL SIZE TEMPORARY USE SPARE TIRE
P275/60R20 BSW ALL SEASON TIRES
GOODYEAR BRAND TIRES
20X8.0 ALUMINUM CHROME CLAD WHEELS

That is from my Build Sheet, also know as the Equipment Listing

found here

FCA RAM

fcagroup.my.site.com