A friend gave me 4 chrome wheels with tires (from a Miata)and I was going to mount them on my 2007 Mini Cooper S. The bolt pattern is the same but the Mini lug bolts are too large to fit the holes. Is it Kosher to bore lug holes? They are 1-2 mm too small.
Just beause the bolt pattern matches, doesn’t mean it’s a good fit. Wheel width, off set etc. should match as well. I would give them back…besides, just boring them out isn’t enough as to do it right may be too much trouble. It’s something you should hire out if you don’t want to find yourself with a wheel and a different center. Sell and start over…
Yep, skip it, not worth it, you’ll likely end up with a set of useless wheels. Sell them.
Is that 1 to 2 MM too small, or 1/2 MM too small?
If it’s 1/2 of one MM I don’t think drilling them would be an issue. That’s less than .020" in diameter, or .010" in radius. Just be sure you get the right sized bit. Don’t go oversize.
The difference in offset will be determining factor. The Mini is FWD, the Miata RWD. I think the offset would be quite different. Also, will the Miata wheels fit over the Mini brake calipers? If not, quit while you’re ahead.
You can play with drilling out the holes if you dare. Not fun to have a wheel fall off at about 70mph and no guarantee that won’t happen.
We don’t even know if the rims fit otherwise. You WILL be ruining a good set of rims you could sell otherwise. They are steel and not alloy and not worth the trouble or problem.
When deciding to attempt doing something like this, I like to consider the “worst case” scenerio. If the worst that could possibly happen if the experiment fails is minor, like perhaps a grill falling out, I try it. If it’s major, like a wheel falling off, I don’t even consider it.
Drilling the rims would be performing an experiment. Worst case, a wheel could fall off on the highway and you could plunge over the edge of a cliff and die a firey death.
This experiment fails my “worst case” test. I recommend against it. Spring for the proper rims.