wrote in message
oups.com...
Fuel consumption figures for Mercruiser marine engines:

3.0 L: 6gph at 3500 cruise, 11.5 gph WOT
4.3 L (2 bbl): 8.5 gph at 3500 cruise, 16.7 gph WOT
4.3 L MPI: 9.0 gph at 3500 cruise, 19.5 gph WOT
5.0L (2 bbl): 9.0 gph at 3000 (not 3500) cruise, 20.5gph WOT
5.0 L MPI: 10.9 gph at 3500 cruise, 22 gph WOT
350 Mag MPI: 12gph at 3500 cruise, 22gph at (5000 rpm) WOT
MX 6.2L MPI: 13.2 gph at 3500 cruise, 25.1 gph at 5200 WOT
496 Magnum: 16.0 gph at 3500 cruise, 30.5 gph at WOT
496 Magnum HO: 18.5 at 3500 cruise, 33gph at 5000 WOT.


Hmm, lets see: Running a pair of 496 HO gassers at well above cruise
speed would likely burn
close to 30 gph per side or 60gph total. 60 gph X $5/gal = $300 per
hour in fuel costs. Over $2000 for an all-day high speed run.

Running the same engines at 3500 rpm cruise would burn 37 gph, for a
total of $185 per hour in fuel costs at $5 a gallon. Still not cheap by
any stretch of the imagination, but at least not as far out of the
questiong for most folks as a $2000 daily (or even weekend) fuel bill
would be.


Our 21 foot runabout is powered by a single 190 HP 4.3L Volvo Penta I/O. We
normally cruise at about 3200 rpm, although we may run it up a bit to catch
up with some friends on the Lake or to get somewhere.......fast. This boat
cruises at 35 mph and will do close to 50 mph WOT.

Most of our high fuel consumption comes when we pull the kids skiing or
tubing. As we only purchased this boat late last summer I have not had the
chance to develop any GPH estimates when cruising vs. pulling our kids on
skis or in tubes....but the bottom line for us is that the fuel price
increases will not be a problem or impact our new boating habits.

I am certainly glad we sold our 32 footer with twin 260HP engines. ;-)