how tight CAN you squeeze a tire?

Thinking about challenge tires and wheels again. I have a set of 245/45R16 hoosier A7s that I would love to use again at the challenge. but right now they are on BMW wheels (16x8, 5x120 pattern, low offset). If I look long and hard for used saab rims, there are plenty of 16s for cheap. Widest they go however, is 16x6.5.

So, my main question: can you squeeze 245/45 hoosier A7s onto a 6.5 inch wide rim? Tire rack says 7.5-9 is the allowable rim width range.

If the answer is yes, great. If the answer is no, here are a few options (saab rims are 5x110 pattern, high offset):

1. I can get 16x7 steelies from a pontiac g6. They are a little more than $50 each new and I bet I could do half that at a junkyard. Still a little skinny though for the tire, and surprisingly hard to track down.
2. I can get hub adapters to run the BMW wheels. This would add like 80-100 to the budget for the adapters, and combined with the offset problem means the wheels will poke out like 2-3 inches from the car on both sides. Not exactly optimal for autox.
3. I will hopefully be picking up some viggen wheels for the saab on the cheap, for street tires. They are 17x7.5, so an option is I could buy a suitable re71r or rival S and just use those for the challenge.

Thoughts?

They'll probably mount on the 6.5s. They'll look like trapezoids, but who cares? I've seen 215 A6s on 13x5.5 Civic steelies done and it worked. Wasn't ideal, but even with cycled A6s it was still a decent bit faster around the cones than 195 Z1 Star Specs on 14x6s on the same car.

The answer is very different for Hoosiers than for street tires.

Yes, 245 on a 6.5 should work. Everyone ran 225 Hoosiers on 6" wide wheels all the time on ES Miatas back when that was a thing. From that point you're adding 0.75" of tire and 0.5" of rim...whatever, close enough.

For a Hoosier, yes, it'll work. People used to run the 275s on 15x6" wheels in stock classes, and I have personally run 205/55R14s BFG R1s on stock Miata 14x5.5s, which is a similar squeeze. It's certainly not the ideal wheel for that tire, but if that's all you can get it'll work.

I was 315/35-17 takeoffs from a Corvette mounted on SN95 17x8 (I think) wheels.

Outer tread blocks were vertical

Knurled wrote: I was 315/35-17 takeoffs from a Corvette mounted on SN95 17x8 (I think) wheels. Outer tread blocks were vertical

Reminds me of when a friend put 225/50/15 slicks on 15x6s...looked like he was driving on 4 sportbike rear wheels!