I have heard exhaust velocities do differ from the the bigger engines like a P-200 compared to a 120 or 160 with the 200 having a lower velocity, but this is second-hand. It was also explained as an example using a KingCat/P-200 vs. KC/P-160. I've seen the same exact KC flown with both engines and it sure was hard to tell a difference between the two even with the 200 putting out nearly 10 more pounds of thrust. Granted, I was not flying it, so I couldn't "feel" the difference, but it was hard to see a difference, if any. I'm sure a difference could be quantified with some data, but I doubt in the box we fly.