1984 Montauk with E-TEC 90 Fuel Economy

Optimizing the performance of Boston Whaler boats
cinegamma
Posts: 12
Joined: Thu Mar 24, 2016 8:49 am

1984 Montauk with E-TEC 90 Fuel Economy

Postby cinegamma » Mon May 16, 2016 5:43 pm

I just finished a round trip on the Tennessee River to Chattanooga, Tennessee from Guntersville, Alabama, [traveling in a 1984 Boston Whaler MONTAUK with an Evinrude E-TEC 90-HP engine]. The total length of the trip was 229-miles using 34-gallons of fuel for a 6.7-MPG average. There were three adults at approximately 200-lbs each, an overnight bag for each person, a large cooler with drinks and food, and 22-gallons of fuel (when tank was full). The majority of the trip was run at 3,200-RPM with a speed around 28-MPH. The E-TEC 90 is mounted three-holes-up with a 17 SST propeller.

kwik_wurk
Posts: 110
Joined: Fri Oct 16, 2015 3:23 pm

Re: 1984 Montauk with E-TEC 90 Fuel Economy

Postby kwik_wurk » Tue May 17, 2016 4:30 pm

Good notes. [The report of 6.7-MPG] equates to 5.8-nautical-miles-per-gallon.

You said "three-holes-up." Can you [show] a picture with the engine lowered to show the alignment of the [anti-ventilation plate] to hull bottom?

I am hoping to get 6-nautical-miles-per-gallon at 3000 to 3050 RPM at 19 to 20 nautical-miles-per-hour from my new 90 E-TEC. That would match speed and RPM and improve [fuel economy] compared to my old two-stroke-cycle 90 Mercury.

jimh
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Joined: Fri Oct 09, 2015 12:25 pm
Location: Michigan, Lower Peninsula
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Re: 1984 Montauk with E-TEC 90 Fuel Economy

Postby jimh » Wed May 18, 2016 1:21 pm

The report of 6.7-MPG can be calculated in many other units. A common unit of fuel economy is liters-per-100-kilometers. A report of 6.7-MPG calculates to 35.1-liters-per-100-kilometers.

Another common unit of fuel economy is miles-per-Imperial-gallon. A report of 6.7-MPG calculates to 8.05-miles-per-Imperial-gallon.

The reduction in fuel used when changing to a modern engine from a conventional two-stroke-cycle outboard engine with carburetors can be approximated by using a factor of reduced fuel consumption of 0.6-times.