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View Full Version : Better Gas Mileage with new prop


vision
07-11-2008, 06:03 PM
Once again Eric at OJ Props comes through. I emailed him that I wanted to get a slightly better hole shot from our 2008 MCX X-star as the stock prop was sluggish with the boat moderately weighted. However, I did not want to sacrifice fuel economy. I thought that since we fall constantly and are pulling up riders more than holding speed, a better hole shot may actually improve fuel economy.

Eric sent me a prop to test, then made some adjustments, and here are the results:

Stock prop 14.25 x 14

1500 lbs ballast and 3 to 4 riders
24.6 mph = 3350 rpm
35 mph = 4100 rpm
6.1 GPH average

New prop - 14.75 x 13 with extra cupping

1500 lbs ballast and 3 to 4 riders. Approx 25% better hole shot
24.6 mph = 3400 rpm
35 mph = 4250 rpm

5.2 GPH average

I made sure to test both props under identical water and ballast conditions with the same riders. All we do is ride. If we did significant unweighted cruising, the old prop would probably have better fuel economy.

We ride about 150 hours a year. That is an expected fuel savings of 135 gallons and at $4.00/gallon, that is a savings of $540.00. Next Summer when gas is $5.00, then we will be saving $675.00!