Motomano

This is intended for owners who had bigger than stock tires, either with OEM wheels or not; recently installed 245/60R18 on my 2007 stock wheels, and due the SHAWD it is not advisable to use a smaller diameter tire, seems it would be better if absolutely needed to set the spare on the front since it has an open differential there, I found the spare compact tire of a VW Touareg/Porsche Cayenne has almost the same diameter than my tires ( minus 7 mm), still looking for if this compact 195/80/18 tire would fit the stock spare rim, but I am curious enough to start this and ask other owners their solutions, I know most gets a full size rim/tire instead of the donut, since running diferent diameter tires on the same axle would damage the SHAWD system, but there must be different solutions for the same issue.

Tomtwtwtw

Your spare wheel is 17" diameter, so that tire will not fit. Obviously a full size spare is the best option, but only if you don't mind losing a good chunk of your cargo space. If you can get a rim to fit that spare tire, and it still fits in the spare wheel well, you seem to have a decent alternative in place. Now if you can find yourself a 195/80/17 tire, you'll be only 1% off from your current size tires and should be perfectly fine for temporary use.

mrgold35

It shouldn't matter the rim size. The overall diameter of the tire is what needs to be within a certain % of OEM. Depending on your type of tires, the new size might be pretty close to OEM diameter. You can check on Tire Rack in the "spec" section to get the diameter of your up-size tires you have now. The donut spare you have might be A-OK.

Tomtwtwtw

What I read is that he has a 195/80/18 tire and was going to try and fit it on the spare 17" rim, which is obviously not going to happen. So at that point you have a choice of getting a new spare 18" rim or a different spare tire to fit the stock 17". I'd try to find a 195/80/17 tire first if one exists. 195/80/18 is off by about +2.5% vs. -1% in a 195/80/17, in relation to a 245/60/18 tire.

Motomano

I am very sorry, my keyboard did a mistake ( happens quite often ;-) ) I apologyze;
the Touareg/Cayenne/Q7 compact spare tire is 195/80/17, it cames compacted with no air at all, as a matter of fact, eBay images makes me guess of vaccum compacted, those SUV's has a compressed air outlet to inflate when needed, now I just need to lurk in junkyards for one, I guess installing on the RDX spare rim will not be a problem.

Tomtwtwtw

Gotcha...in that case if you can get it mounted to that rim I think you'll be in pretty good shape.

BigHatch

Spare Tire Replacement on Tire Rack

Motomano

Thsnks BigHatch, the closest match will be the 195/80/17, I hope I never need to use the spare but I would like to be prepared, for over 10 years I had not a flat in any vehicle, this year 2 times, one in my motorcycle and the one in the RDX, so it is better to anticipate.