New Tires

I debate the higher top speed part....
obviously acceleration would be improved with the smaller tires due less rotating mass. Not to mention it takes more effort to move weight that is further out. But the bigger tires did mean a potentially higher top speed. Other than that Fuzions arent bad tires. Not great. But defintely good.

But anyway that smaller tire is just simply spinning faster while the larger one spun slowler.

With the 225/70/15's on your speedometer was -6.4 mph off at 60 meaning you were doing 66.4
With the 195/50/15's on your speedometer was +5 mph off meaning at 60 mph you are doing 55mph.

This is assuming your car has the correct gear for the speedometer and tire size and such.

Just fyi for you.....

Ill stick with my 225/60/16 z rated firestones
sure they rub alitle when i turn hard with some one in the pasinger seat but i can live with it. the car turns like a bat out of hell!

I see your reasoning... But since you made such a large jump in tire size. from one real far off tire size to basically another its hard to say. But I will say this. Your most likely not any faster than a stock tired car. My 89 Coupe came with 195/70/14's it now has 215/60/15's on it. Felt no difference at all except she is more stable higher up and while cornering.