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370 OUTRAGE Fuel Economy

Posted: Wed Jul 03, 2019 7:37 am
by lets_get_tropical
Good Morning. I recently purchased a 2017 370 Outrage with triple Mercury VERADO 350 engines turning REVOLUTION4 20-pitch propellers. Fuel mileage is about 0.86-MPG with a light load at cruising speed. I am particularly interested in [improving] the fuel economy at cruising speed.

I'm thinking of switching to ENERTIA ECO 18-pitch propellers.

What sort of performance are other 370 OUTRAGE boats with triple VERADO 350 engines getting?


Re: 370 OUTRAGE Fuel Economy

Posted: Wed Jul 03, 2019 8:49 am
by flymo
My boat typically gets between 9.5 and 10 miles per gallon at cruising speed.

If fuel economy is a concern I would suggest getting a smaller boat.

Re: 370 OUTRAGE Fuel Economy

Posted: Wed Jul 03, 2019 10:31 am
by Phil T
I would review the performance report:

If you are not even close to these numbers, I would then consider a change in props but you probably will not see significant improvement. Remember that you are piloting a 16,000 lb. boat with over 1000 hp.

Re: 370 OUTRAGE Fuel Economy

Posted: Wed Jul 03, 2019 3:51 pm
by flymo
More seriously, the performance report shows the boat hitting 6400 RPM with the REVOLUTION4 propellers, although the report is garbled and it's unclear what pitch was being run. Assuming they meant 20-pitch, and that your boat has the stock propellers, then it sure seems like you'd be way under-propped with 18-pitch.

If mileage really matters to you, you could consider removing and selling your center motor. You'd probably still get pretty good performance, likely equivalent to how that boat performs with the triple 250-HP engine setup, as you won't have the drag of the third gear case in the water, nor, of course, the weight.

To find the right propellers may take some experimentation, but I think your fuel mileage would improve, possibly getting up to the 1.3-MPG region; that guess is based on the performance report of the Outrage 330 with twin Verado 350 engines.

Re: 370 OUTRAGE Fuel Economy

Posted: Fri Jul 05, 2019 5:14 pm
by jimh
I would have expected Boston Whaler to have delivered a 370 OUTRAGE with ENERTIA or ENERTIA ECO propellers instead of the REVOLUTION4 propellers. If you look at the more recent Boston Whaler performance test reports, almost all their boats are getting ENERTIA three-blade propellers for the VERADO engines.

First-generation VERADO owners were not happy with fuel economy, so Mercury focused on improving that in the second-generation VERADO. I would expect that a c.2017 boat would have the second-generation VERADO engines.

Even with the improved fuel economy from the second-generation engines, owners were still disappointed with the engine's fuel consumption, so Mercury responded by developing a new propeller, the ENERTIA ECO, specifically designed to improve fuel economy on a VERADO.

A well-known boating writer called the Mercury ENERTIA ECO propeller a miracle, and cited results of 21-percent to 40-percent improvement in fuel economy in testing against other propellers. Cf.:

Mercury MIRACLE Propeller

On that basis, my expectation is changing to ENERTIA ECO propellers from REVOLUTION4 propellers on a VERADO should enhance the fuel economy.

Contact PROP-GODS for advice about pitch and other factors. They probably have much more collected knowledge about the VERADO on big hulls like a 370 OUTRAGE than anyone.

Re: 370 OUTRAGE Fuel Economy

Posted: Fri Jul 05, 2019 7:13 pm
by jimh
I found this performance report from Boston Whaler: ... UTRAGE.pdf

I think it is the same one as posted earlier by Phil, just located at different web URL. In general, I would give the data from these tests the most weight in evaluating how a particular 370 OUTRAGE is performing; the Boston Whaler data probably represents the best performance that the company test drivers could coax from the boat, engines, and propellers, at the time of the test.

Note that air and water temperatures have an influence. For the 350 triple test the air temperature was 90-degrees-F (hot weather for me) and the saltwater temperature was 86-degrees-F (really warm water for me). When making comparisons, the air and water temperatures should be similar. Colder air and colder water will improve performance. Freshwater performance will be lower due to water density change.

For the triple 350 VERADO set-up the propellers are REVOLUTION4 in 19, 20, and 19-pitch. I assume the 20-pitch is on the center engine and the outboard engines have 19-pitch.

The MPG at cruise is reported to peak at 0.99-MPG (that is statute miles per gallon) at 29.4-MPH (again statute miles) with the engine speed 3,500-RPM.

The test was conducted in January 2015. The ENERTIA ECO was just being introduced in 2015. The ENERTIA ECO may not have been available to Boston Whaler when they were testing the 370 OUTRAGE, so the ENERTIA ECO might not have been tested with this rigging.

The tests of other versions of engine power on the 370 OUTRAGE were done in 2011. At that time there was no ENERTIA ECO available, and the REVOLUTION4 was probably the best choice. Perhaps the prior experience using the REVOLUTION4 propellers led to Boston Whaler using them on the 350-HP engines, too.

The REVOLUTION4 propeller diameter is only 14.6-inches, while the ENERTIA ECO will be a 16-inch diameter. The REVOLUTION4 is also available in pitch increments of 0.5-inch. The ENERTIA ECO is only available in one-inch pitch increments, except for an 18.5-inch pitch model.