The test was conducted in twin 5.0 L Volvo Penta gas engines with conventional oil and with Royal Purple. We took sound readings, speed and fuel flow data.
Even though we have heard for decades that synthetic motor oil can enhance an engine’s performance we paid that advertising little mind, and used whatever the boatyard or the marina was selling. But the claims of Royal Purple finally became too strong for us to resist, so we decided to put the oil to the test early this summer. We made a video as we were testing in situ to document what we discovered. As regular readers already know (we have been leaking the news out because we couldn’t resist), the tests were surprising. The engines we used had 115 hours on them. We put in conventional oil and ran the engines for one hour before testing to get our control numbers. Then, we changed oil and the oil filter, using Royal Purple products, and tested once again. What we found was a impressive 6.3% increase in WOT speed and an improvement in fuel efficiency at best cruise of 9.3% with Royal Purple synthetic motor oil. Take a look at the test documentary video--