I just got a new set of 205/60/15 tires in my shop, mounted on BMW rims. My Park Ave uses 205/70/15. Will these fit on my car? I'm trying to save a couple bucks here.

With those tires your spedo will be 6.1% faster. So when the display is 60, your actually going 56.3 Yes, they will fit.

Seeing as how I have a lead foot anyways that'll be a good thing LOL. Thanx

It does give you a little extra torque.

So let me get this straight I put on a 60 series tire and I move the earth because I have all this extra torque? Sweet!

Well, don't know if I would go that far. But it is just a little more torque.

It also should be noted that the tire is shorter in height and runs the risk of looking horrendously stupid.

Won't know until you try though.

You will effectively lower the overall gearing 6.1%, good for off the line acceleration, not so good for fuel economy.
Do you know the history of the tires?, if they haven't been driven on the road that should be fine, if they are a little used they may well have been abused particularly if they came off a wreck.

I decided I'll just save for some new ones. But these tires are brand new, they came off of some kind of BMW (wheels look late 80s early 90s). I don't know why tires gotta be so expensive

You think that'* bad, try looking for tires for the guys that have 16'*. 225/60r16, then you will realize it is not that bad. My tires were walmart specials, got the set for under $300 out the door.