I used to fish out of a friend of mine's 201 that had a 150 johnson fast strike on the back. I think it was a 96 model. That boat done just fine with the 150 on it. Hole shot was good, it wasn't fast, but it was fast enough. My friend still swears that was the best driving, handling, and fishing boat he's ever had and a lot of times he wishes he had it back. There used to be a lot of 201's powered by 150's back when BASS had the 150 hp limit in place. I'm not saying it would be a good idea to underpower one, but it could be done and the boat would still do fine. Whether or not it would save any fuel over backing off the throttle of a bigger motor is the question and I don't have a clue about that. I do know the 201 I fished from with the 150 done really good on gas for a carbed engine. Better than most others I've been around.