Does the 15"x6" steel wheel that came on a 2001 Impreza have the same offset and other details as that for a 97 Legacy Outback? I want to get a full-sized spare.

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How about a 2000+ Outback Vs. a 96-99 Outback? Do they have the same bolt pattern and offset? I like those wheels more than my 15" 6 spoke.

Here's the breakdown of lug patterns, I don't know offsets though:

 

Anything that fits in the Old Gen forum (besides the Justy and XT6) has a 4 X 140 lug pattern. It's so unusual that the only way to change wheels is to get other Subaru wheels or Peugeot wheels.

 

The Justy has a 4 X 100 lug pattern, the XT6 has a 5 X 100 lug pattern like the New Gen.

 

Anything that fits in the New Gen forum(except for the SVX and 05 Imprezas) have a 5 X 100 lug pattern. This makes all kinds of aftermarket wheels available for Subarus.

 

The SVX and 05 Imprezas have a 5 X 114.3 lug pattern, which limits them somewhat in aftermarket, but still more than the Old Gen.

Most (if not all) of the Subaru 5x100mm wheels fall into the 50-55mm offset range (with a couple of the JDM STi wheels as low as 48mm). So pretty much any Subaru 5x100 wheel, should fit pretty much any other 5x100 Subaru car without offset issues (of course, there may be brake size issues, width issues, etc...but offset should be fine).