Just wanted to comment on the performance of Mercurys' new Enertia prop. I've been running one for about 3 months on my 1995 Ranger 690. Boat motor is 2003 Mercury XR6 150 hp along with a 9.9 pro kicker on transom. Prop is Mercury Enertia 19 pitch.
Top speed recorded on gps while running light load-1/2 tank of fuel, 1 person, and calm conditions is 52 mph.
Fully loaded with gear, full tank of gas, and two passengers, speed is around 48 mph. Able to hit between 5400 and 5600 rpm on tach at full throttle and trim.
Prop provides a nice combination between holeshot and top speed. Only downfall of prop is the tendency for the boat to purpoise between speeds of 25 and 30 mph. I've found that trimming the motor down and or increasing the throttle helps eliminate the tendency to bounce.
This prop is vastly better than the 21 pitch Stilletto prop which I replaced with it. Mercury is advertising the list price on these props at $650, but I was able to get mine from a reputable e-bay dealer for $450. Just thought I would put this feedback out there for anyone condisdering trying one of these props. Thanks for reading...