Recently Volvo-Penta enjoyed the opportunity
to conduct performance testing onboard two new, identical 35-foot
Regal Express (3560) sterndrive-powered express cruisers. The gasoline-powered
Regal had twin big-block gasoline engines producing 420 HP each,
driving a 1.78 reduction DuoProp sterndrive with an F-5 propeller.
The diesel-powered Regal was equipped with twin 285 HP Volvo-Penta
KAD300 electronically controlled, 6-cylinder engines driving a
1.68:1 ratio DuoProp sterndrive and a C-6 propeller. If you have
ever heard,
“If you only use your boat 200 hours each year, you don’t
need a diesel…”
“It will take you 5 years to see a return on the diesel
investment…”
“Diesel is nice, but a gas engine is just faster…”
…then we suggest you
read on.
Test conditions were comparable
and speeds were measured in two directions – into and away from the wind with each engine
operating at 3,500 RPM. Due to the differences in fuel, water and
people on board, the diesel vessel cruise weight was 18,054# while
the gasoline Bessel cruise weight was only 16,476#. While the Volvo-Penta
diesel-powered vessel carried 1,587# more weight and produced 32%
less total horsepower, the results are impressive. Range figures
below are calculated at 90% of total fuel tank capacity. Maximum
boat speeds recorded were 53.4 MPH for the gas-powered Bessel and
44.5 MPH for the diesel-powered vessel. However, since the majority
of an operator’s time is spent at or below cruising RPM,
the test data below is based upon approximate cruise RPM for each
propulsion package. The test report results were startling even
to some very experienced boat builders and Volvo-Penta personnel.
| |
Gasoline V-8 |
Volvo-Penta
KAD 300 Diesel |
Result |
| Speed |
34.1 MPH |
40.9 MPH |
Diesel 20% Faster |
| Miles / Gallon |
1.2 MPG |
1.7 MPG |
Diesel 41.Farther |
| Gallons / Hour |
28.1 GPH |
24.3 GPH |
Diesel Consumes 15% Less Fuel |
| Range in Miles |
300 Miles |
468 Miles |
Diesel Travels 56% Farther |
| Range in Time |
8.8 Hours |
12.7 Hours |
Diesel Travels 3.9 Hours (44%)
Farther |
| 100 Hour Consumption |
2,810 gal. |
2,430 gal. |
Diesel Consumes 380 Gallons
Less per 100 hours |
| Propulsion |
MAX HP |
Fuel @200 Hours |
Fuel Cost / Gallon |
100% Financed Payment |
Fuel Costs @ 200
Hours |
Monthly Savings* |
Annual Savings* |
| Gasoline V-8 |
420 |
5,620 g |
$1.99 |
$1,303 |
$11,183 |
|
|
| VP KAD300 Sterndrive |
285 |
4,860 g |
$1.53 |
$1,490 |
$7,435 |
$125 |
$1,504 |
* Savings Based on feul cost at 200 hours
While the initial purchase price of diesel resulted in a 100% financed payment
per month of $187 more, the efficiency and economy of the diesel yielded a $125-per-month
savings at 200 hours per year of operation. In addition, diesel owners may anticipate
lower insurance premiums, the confidence of diesel safety and durability, as
well as significantly higher resale value realized by owners of well-maintained
diesel boats.
