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Forester Spare tire question

I have a 2009 Forester. It has a toy spare, and 16" wheels. The car will accept 17" wheels as well. I have an unused 17" wheel and tire from an earlier (and now deceased) Outback (same bolt pattern, etc).



I am driving to Alaska by some very uncommon routes. So here’s the question: if I take the 17" spare and have to install it for a few hundred miles, what happens? What are the risks? I really don’t want to buy a 16" wheel / tire if I don’t have to!

Too bad you did not get the XT package because it came with 17 inch wheels. I would not risk driving the Forester a few hundred miles with an odd wheel. Alaska can be a place where you may have to drive hundreds of miles to get a flat fixed. I would buy a 16 inch wheel and tire combo that matches your wheels exactly. The AWD system can be damaged if you don’t keep all 4 wheels the same diameter. Check the air in the spare often.

I would go to a junk yard and trade the 17" spare for a 16" spare. It shouldn’t cost that much. You could even put a used tire on the spare full sized rim. Then I would take both the small spare the the full size spare on the trip. That’s what I do when I go on long trips in my car. Having two spares can really come in handy when you get a flat in the middle of nowhere on a Saturday night and no tire stores are open.

Before doing anything else, check the tire circumferences. If identical, or very close, you should be ok. With all the tire sizes available, this is possible.

Thanks, folks. I’m getting a full size spare and am finding a way to carry it. Pix when finished!

As I recall that Forester has a strict requirement to have all four tyres all the same size (very little difference allowed) or you can damage some expensive drive parts.

A spare is only for temp use(<50 miles) on a Subaru whether full size or temp.

The reason is the AWD drivetrain can get damaged if a tire is more than 1/2" in rolling circumference vs the other tires. The 16" vs 17" is irrelevant. The thing that matters is the circumference (distance around properly inflated tire).