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One of the big problems with petroleum based engine oil is the hotter it gets the less able it is to prevent metal-to-metal contact. It’s called thermal viscosity breakdown. However with Royal Purple synthetic oil, the stability of the oil is far superior so when the motor gets hot, we don’t have that problem.

Note: Improvements in performance depend on the vehicle, it’s condition and how it’s used. This video is not intended to imply that all users will experience the same performance gain by upgrading to Royal Purple.


Steve: Welcome back to Hot Rod Magazine TV. Synthetic lubricants are a pretty controversial subject in the world of hot rodding. Do they really work? Well, today, with some help from Royal Purple, we're going to find out. Our test car is a 1965 Mercury Comet two-door Sedan. It's got a 347 Stroker motor, a Tremec five- speed manual transmission, and a nine-inch rear axle. The owner uses it for general street and strip use, and he's got a nice Eddie Schartman AFX vibe that I really like.

Now, we're going to begin our testing here at Westech Performance with the petroleum-based oil in the engine, transmission, and rear axle. Then, we'll switch to the Royal Purple synthetic fluids and see what kind of a difference we get. Our dyno expert today is John Baechtel at Westech Performance in Mira Loma, California. So, John. How does our baseline look with the petroleum-based oils?

John Baechtel: Well, it looks pretty good, Steve. We've got 408 horsepower at the rear tire.

Steve: Wow, that's not bad. Well, let's change to the Royal Purple and see what happens. We'll begin our fluid transfusion with the engine. Now, one of the big problems with petroleum-based engine oil is that the hotter it gets, the less able it is to prevent metal-to-metal contact. It's called thermal viscosity breakdown. However, with Royal Purple synthetic oil, the stability of the oil is far superior. So, when this motor gets hot we don't have that kind of a problem.

Modern manual transmissions, like this Tremec, are designed to use automatic transmission fluids like Dexron. And yes, Royal Purple makes a synthetic, Dexron-type fluid. Now, in the case of this car that makes 500 horsepower, when this car goes to the drag strip and power shifts this transmission, it's going to need all the protection it can get against the oil being squeezed out from between those gears. The Royal Purple will do the job.

The nine-inch real axle in our Mercury has a limited slip clutch- type differential. When it goes down the freeway in overdrive, the ring and pinion are spinning at a really high rate of speed. To prevent heat and provide good lubrication, the Royal Purple synthetic fluid is an excellent choice. So, John. What's the verdict?

John: It looks like you picked up 10 horsepower at the same RPM.

Steve: No kidding? So, it looks like Royal Purple, the synthetic fluid, really did the job. We'll probably see better fuel economy and reduced wear down the road.

John: I think so.

Steve: It's time to let it rip and find out what that extra 10 horsepower feels like.