The best indicators of powerboat cruising performance are: (1) fuel efficiency expressed in nautical miles per gallon (NMPG), just like automobiles and (2) speed attained per horsepower installed. With these criteria, MJM Yachts is #1.
Open the data sheet LINK: MJM Fuel Efficiency Comps & Observations
Using detailed published data, it shows how 5-MJM models outperform other brands and types of powerboats...debunking some long held industry shibboleths in the process.
WHAT THE DATA SHOWS
Open the data sheet LINK: MJM Fuel Efficiency Comps & Observations
Using detailed published data, it shows how 5-MJM models outperform other brands and types of powerboats...debunking some long held industry shibboleths in the process.
WHAT THE DATA SHOWS
1. Diesel I/Os are twice as efficient as gas outboards. A cruise-equipped MJM 29z with single 260 HP diesel I/O weighs the same as a Hunt Surfhunter 29 with twin 250 HP outboards. Harbor cruising at 8.3 knots, the 29z is 3.5x more fuel efficient...burning 2 gph vs. the Hunt’s 7 gph. Cruising at 25-26 knots, the MJM is 2x as efficient, getting 3.0 nmpg vs. the Hunt’s 1.5 nmpg.
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| Volvo Penta D4 260 HP Diesel with DPH DuoProp Drive |
2. “Hypebrids" is a better description. A diesel/electric hybrid is not yet the answer. The Greenline 33 Hybrid weighs the same as an MJM 34z. At a displacement speed of 8 knots, where you’d think a hybrid would excel, the MJM is more efficient. Top cruising speed (using 87.5% of wide open throttle) for the Hybrid is 12.2 knots, the MJM is 26.6 knots.
3. Jet drives are not efficient. The MJM 36z (twin 220 HP Volvo Penta D3s) weighs the same as a Hinckley Talaria 34 (twin 260 HP Yanmar 6LY3s) with jet drives. The MJM 36z gets twice the mileage of the Hinckley and is 2 knots faster. You will also note a difference in engine/drive packages. The lighter Volvo D3s on the 36z are more fuel efficient than the heavier optional Yanmar 6LY3s.
4. Weight and beam are major performance factors. A Sabre 42 and MJM 40z have similar length on deck and the same IPS 500 propulsion package. The Sabre is nearly 50% heavier and 2 feet wider. The epoxy composite MJM has (a) the stability from a lower center of gravity to earn ISO Category A Ocean Certification vs. the Sabre's B Rating, (b) 50% better fuel efficiency, (c) an upper end cruising speed of 34 knots which is 5.9 knots faster, and (d) greater range.
5. Pound for pound and dollar for dollar you get more with an MJM. The Hinckley Talaria 43 (2x550 HP Cummins powered jet drives) and the 6 foot longer MJM 50z (Volvo Penta 2x435 IPS 600 pod drives) are the same cost per pound, $56. But, the differences are astounding. Apart from 15% more living space, the MJM 50z with 230 less HP has a 2 knot advantage in upper end cruising speed. At the same 25 knot cruise speed, the MJM burns half the fuel with a 200 mile greater range.
6. Triples are as fuel efficient as twins. The MJM 50z with triple IPS 600s has marginally better fuel efficiency than that same MJM 50z hull powered with twin IPS 600’s. It’s all about the amount of HP applied to overcome resistance at a certain speed... even at displacement speeds. Seems 3 sets of props do a better job of separating the hull from the grip of the water than 1 or 2 sets of props, even with the heavier engine weight.
7. Trawlers are slow, not fuel efficient. Pushing bluff, heavy hulls through the water at anything beyond 10 knots puts fuel efficiency ratings below outboards and jets. The Beneteau 44’ Swift Trawler 50 (anything but “swift”) at its top cruising speed of 20 knots goes a half nautical mile per gallon (40 gph) while the triple IPS 50z at 35 knot cruise goes 3/4’s of a mile per gallon (48.5 gph). The Grand Banks 43 with 2x480 HP Cummins burns more fuel at 10.3 knots (25.4 gph) than a 50z at 24 knots (24.0 gph).
8. Traditional construction results in low performance. This is evident in the Tiara 50 Coupe and the Asian built Hunt 52. Compared to the high-tech and admittedly more expensive advanced epoxy build of the MJM 50z, the Tiara and Hunt burn nearly twice the fuel at comparable speeds and have a 5 knot slower top end cruise speed with reduced range.
4. Weight and beam are major performance factors. A Sabre 42 and MJM 40z have similar length on deck and the same IPS 500 propulsion package. The Sabre is nearly 50% heavier and 2 feet wider. The epoxy composite MJM has (a) the stability from a lower center of gravity to earn ISO Category A Ocean Certification vs. the Sabre's B Rating, (b) 50% better fuel efficiency, (c) an upper end cruising speed of 34 knots which is 5.9 knots faster, and (d) greater range.
5. Pound for pound and dollar for dollar you get more with an MJM. The Hinckley Talaria 43 (2x550 HP Cummins powered jet drives) and the 6 foot longer MJM 50z (Volvo Penta 2x435 IPS 600 pod drives) are the same cost per pound, $56. But, the differences are astounding. Apart from 15% more living space, the MJM 50z with 230 less HP has a 2 knot advantage in upper end cruising speed. At the same 25 knot cruise speed, the MJM burns half the fuel with a 200 mile greater range.
6. Triples are as fuel efficient as twins. The MJM 50z with triple IPS 600s has marginally better fuel efficiency than that same MJM 50z hull powered with twin IPS 600’s. It’s all about the amount of HP applied to overcome resistance at a certain speed... even at displacement speeds. Seems 3 sets of props do a better job of separating the hull from the grip of the water than 1 or 2 sets of props, even with the heavier engine weight.
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| 50z With Triple Volvo Penta IPS 600 Drives and Interceptor Trim Tabs A 50z is Truckable, Fitting Under the 13'6" Height Limit with Drives in Place |
7. Trawlers are slow, not fuel efficient. Pushing bluff, heavy hulls through the water at anything beyond 10 knots puts fuel efficiency ratings below outboards and jets. The Beneteau 44’ Swift Trawler 50 (anything but “swift”) at its top cruising speed of 20 knots goes a half nautical mile per gallon (40 gph) while the triple IPS 50z at 35 knot cruise goes 3/4’s of a mile per gallon (48.5 gph). The Grand Banks 43 with 2x480 HP Cummins burns more fuel at 10.3 knots (25.4 gph) than a 50z at 24 knots (24.0 gph).
8. Traditional construction results in low performance. This is evident in the Tiara 50 Coupe and the Asian built Hunt 52. Compared to the high-tech and admittedly more expensive advanced epoxy build of the MJM 50z, the Tiara and Hunt burn nearly twice the fuel at comparable speeds and have a 5 knot slower top end cruise speed with reduced range.
