A few weeks ago BoatTEST.com conducted a comparison test on two Volvo marine engines run with conventional mineral-based engine oil and Royal Purple Synthetic Oil. We found that the boat we tested in Long Island Sound had at WOT speed of 4.3% more with Royal Purple and got 6% better fuel economy. At best cruise fuel economy with Royal Purple was 9.6% better. Actual in-water apples-to-apples testing is challenging and we wanted something more. “More” in this case meant testing in “Lab Conditions” and that means on a dyno. We passed that request on to Royal Purple and they commissioned the folks at Horsepower TV to do just that. The test is done and the video of it is up on the Royal Purple website.
Take a look and see the results --