mjoyce6500

I had same question now that I put 20's on my '03. On http://www.1010tires.com/TireSizeCalculator.asp the difference between 275/55 20 and the factory 265/75 16's is .26 inches or 6.6 mm. Question is: Is 1/4" difference in size a concern for the differential? I am not sure, but one could easily get that difference in a new spareand old tire gone flat. I think the side wall is bigger concern since tire flex in the smaller tire would increase the difference in tire size. Has anyone found 20" steel wheels? I could only find them for Dodge trucks..

73shark

It won't be too long 'til all we get is a small compressor and a can of Fix-a-flat.

addkev

This is true. Our BMW did not have a spare, the dealer's answer was that most BMW owners would not change their own tire anyways.

biglg

That is why BMW's come from the factory with run flats! Then when you want to replace the tires you get run flats.

It pissed me off when we bought ours. I will just buy regular tires next time and hell with a spare, i will drive on the rim as long as i can if i have too. It will be cheaper than the inflated price of run flats.

ki4izq

same here 4 polished 20's on the ground, 1 black steel 17 as spare.....

i guess i accept the fact that a spare is a spare not a "primary".... long gone are the days of the tire rotation scheme of rotating in the spare.... now in the days of directional wheels and directional tires.... (i am not claiming stock tahoes have directional but just the general concept) be glad we at least have a real tire and not some small disposable emergency tire.... i guess it is not much of a problem for those folks that the standard 17" wheels.....

Rich2007Z71

I have the Z71 model with 18" Bridgestone and my spare is also a 17" Goodyear - go figure!

tahoe07

Can't rotate it in but a least it is almost the right size...

Spare on and OEM 20 beside it with book to stop it from roilling



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ZX1100F1

The reason that a steel wheel and smaller tire is used for a spare is simple economics:

Reason #1. Most cars in the junk yards have the original spare tire in place and many of those have never been used so why include an expensive spare tire on every vehicle when odds are that it will rarely and in many cases never be used, the price of your Tahoe would have been a couple hundred $ more if a matching spare tire on an aluminum wheel were standard equipment.

Reason #2. A spare tire is intended to be used as a temporary fix untill you can get the primary tire repaired.

Reason #3. The included spare tire can be used without restriction when installed , you can cointinue on your way at normal speed.

Reason #4. A large and wide 20" wheel/tire does not fit as well underneath the vehicle and it is considerably heavier and more awkward, most people will throw the punctured tire and wheel in the cargo comparment, the 20" wheel/tire is very difficult to handle and you will typically have it repaired ASAP so you're not going to want to go thru the hassle of putting it back underneath just to have to get it back out.

Reason #5. If it bothers you that much then purchase a matching spare tire and wheel, GM didn't charge you extra for it, if they had and not given you a choice you'd probably be even more upset.

FYI,
The spare is nearly the exact same circumference as the stock tire; the slight difference will not harm the differential or hamper vehicle performance.

Egarciae2

I just had a flat…nope, spare don’t match. Plus, I had to buy a tire because the dealership said it was unrepairable. I kept the old tire, few days later made time to have it checked out at Firestone. Firestone repaired it, nail hole was not on the side-wall. I’m keeping it as a spare. The question is, will the stock matching rim and tire fit in the spare tire compartment/area?

tech2

no idea what year you have or what size tires you have on so cant say for sure. my 2000 and 2006 gm trucks fit full size spares.