the Nose cone improver the speed 2 mph, but it made a Noticeable difference in handling, the prop don't blow out on turns like it did, I made several tight turns 45 mph to 60 mph and it stayed in the water .. I Like it. BTW I had 26 gallons of gas on board, 100 degree temp, water temp mid 80's, and into a 12 / 15 mph wind, on the back flip with the wind 70.2 gps