Mercury Diesel Sterndrive test ride

[Fr. Frank]

I got a ride today on a 2012 Chaparral 19' deck boat/bow rider powered by a 150 hp 2.0L turbo diesel sterndrive. This boat was just repowered after having "sunk" on the trailer last year. (plug in, lots of rain, dead battery).

Old power was a 3.0L 135hp EFI. I can't speak directly to the performance with the old motor, but the brief ride today was interesting. New power was a reported $23K installed including a new fuel tank. (This was almost $6K more than was quoted prior to install)

Old 135hp gas motor (as reported by owner):
Top Speed - 42 mph
Cruise speed - 25 mph
Fuel consumption at cruise - 5.5 gph
Fuel consumption at 80% power - 8.5 gph (about 35 mph)
Time to plane - "about" 4 seconds

New 150hp diesel motor (observed with Smart Gauges):
Top Speed - 48 mph
Cruise speed - 24 mph
Fuel consumption at cruise - 2.9 gph
Fuel consumption at 75% power - 6.7 gph (about 35-36 mph)
Fuel consumption at WOT (3950 rpm) - 7.9 gph
Time to plane - 4.5 seconds.

It falls off plane at about 17 mph now, He never noticed what if did before. New power plant is about 115-120 lbs heavier than the old, according to the owner.

That's 8.3 mpg at cruise, a 65% increase in economy, and still better than 6 mpg at WOT! New motor has power steering (not ordered, but installed and charged by the dealer in P'cola anyway, an extra $900)

Because of the Diamond 4 Prop, I think with changing the prop he can get better planing performance with the right SS prop.

I noticed it is VERY quiet, even at 75% power. We were able to talk without trying to shout over the engine noise. WOT is still noisy, though.

One thing: Even with the diesel, it still didn't ride like a SeaCraft. It still rode like a Chaparral. :\
And Choctawhatchee Bay was really rough today.