| |
Bertram31.com General Bulletin Board
Gas to Diesel Justification:
Posted By: Capt Patrick McCrary
Date: Friday, 10 June 2005, at 3:39 p.m.
Well, TS Arlene is wetting us down good here in Palm Beach, can't kick over my UV activated resin without the sun shinning, so I decided to crunch some numbers based on the "Gas Range" thread below...
Seems that some of the gas jockeys out there are still having a hard time justifying the diesel conversion debate. Here are some numbers that I put together, all of which can be substantiated just with B31 owners from our group.
Gas lacks torque so wheels must be smaller. This equates to slower speeds at cruise RPM.
With diesel's increased torque, you get more speed, (as much as 50%), increased range, (as
much as 225%), improved handling, and lower maintenance.Resell value is greatly increased with diesel powered boats. Longevity of engine can be as much
as 5 times greater for diesel. A gas engine with 3,000 hours is a pretty tired engine. A diesel
engine with 15,000 hours is usually a pretty tired engine.Gas to diesel conversion will currently cost $10K - $15K, This should include new & over-sized
shafts, new & larger props, fuel tank modification for return lines, wiring, installation, engine bed
beef-up, alignment, & sea trials. Items like aluminum caps & ramps, new fiberglass shaft alleys,
new instrument gauges, new fuel sending unit, & other improvements will bring the coat closer to
the $15K range. This cost can vary greatly depending on the location of the boat & "sweat equity",
so this is just a considered cost range.The cost of a pair of diesel engines with transmissions can be as little as $12K for 4 cylinder rebuilt
"take outs", to as much as $60K for new 6 cylinders from a dealer.Therefore the high end of converting to diesel can be as much as $75K, with a low end of around
$22K. As a general rule of thumb, figure $60K for a turn key new 6 cylinder conversion & $50K
for 4 cylinder. This would all be professionally installed.While there is only a little difference in cost per gallon between gas and diesel, the fuel economy of
diesel is generally double that of gas, which makes your cost per mile traveled half as expensive
with diesel. Couple that together with faster cruise speeds and the cost differential is even greater.A gas powered boat yielding .9 MPG at 20 kts uses 22.2 gallons of fuel at a cost of $2.50 per gallon,
making the trip fuel expense $55.50. A 4 cylinder diesel getting 2.2 MPG at 22 kts takes 54 minutes
to make the same 20 nautical miles. The diesel is burning 9.1 gallons at a cost of $2.25 per gallon,
making the trip fuel expense $20.48.Gas @ 22.2 GPH x 200 hrs per year = 4,400 gallons x $2.50 per gallon = $11,100.00 annual fuel cost.
Diesel @ 9.5 GPH x 200 hrs per year = 1,900 gallons x $2.25 per gallon = $4,275.00 annual fuel cost.Difference is $6,825.00. If the re-power was new engines and pro install, costing $50,000.00, the break
even point in just fuel cost alone would take only 7.3 years. If 40% of your running time is spent getting
to and from the fishing grounds, and you're making 10% better speed with diesel, that's 140 hours
fishing as opposed to 120 hours with gas. If the average fishing day, (actually with lines out), is 5 hours,
that's the equivalent of another 4 days fishing per year.If a gas powered boat has a value of $50,000.00, and the same boat has a value of
$75,000.00 with diesel engines, easily $25,000.00 of the conversion is recovered upon selling. So,
if our hypothetical repower was $50,000.00 & $25,000.00 is recovered, how long would you have to
own the boat to break even? $25,000.00/$6,825.00 = 3.7 years...Now whether or not one has the bucks to pony up a diesel repower is a mote question, but is a diesel conversion economically sound?
Yup, bet the farm on it!
Best regards,
Patrick
| |
Bertram31.com General Bulletin Board is maintained by Patrick McCrary with WebBBS 5.12.