Jun 21, 2010

Royal Purple Motor Oil Review


Many years ago while doing research for a book on motorcycles (a project put on eternal hold) I spent a lot of time looking into the truth behind "motorcycle specific" motor oil and the various oil types - and outright scams - that exist in the marketplace.

One of the things I learned was the all of the "speciality" oils on the market where nothing more than just plain motor-oil with branded additives, sometimes that did nothing more than just add more copy to the marketing of the brand and gave no actual benefit.

Then came the plethora of debates over synthetics vs. traditional oils with most people under the impression that Mobil 1 was the best thing since sliced bread.  And of course who can forget the multitude of DIY oil additives that when supposedly would reduce friction by some unimaginable amount and make you engine run almost indefinitely - as long as you kept using their special oil treatments (remember the over-the-top claims from Slick 50 in the late 80's early 90's?).

But it wasn't until I visited a Texas-based aftermarket exhaust maker that was doing dyno tests on various oils that I actually came across hard, scientific evidence that in fact there was an oil that actually did outperform the usual suspects in the lubrication marketplace.

Up on the dyno was a Honda CBR600 F1 "Hurricane" and the guys were busy testing Mobil 1, Honda's Pro GN 4-stroke oil, Pennzoil, Golden Spectro, Castrol, Motul and a brand I'd not yet heard of, Royal Purple.

The engineers went through an exhaustive testing routine where they filled the CBR with each oil and a new filter, ran the bike up and down the RPM range and measured the actual horsepower output from the motor, drained the oil and tried another brand.  They did this twice for each brand to make sure the first test-run results weren't skewed by temperature or other conditions earlier.

In the end, and to everyone's amazement, the test runs with Royal Purple in the motor actually gave an increase of 1.5 horsepower over everything else indicating that in fact RP was doing a better job of keeping metal parts from staying apart from each other.

The results can be attributed to one major component, film strength, and compared to Mobil 1 which ended up being it's closest contender Royal Purple has a surface film-strength 600% stronger than Mobil 1.  That may sound like way too much but in the world of micro-chemistry where molecules are all that separate metal parts from shearing themselves apart 600% really isn't a lot when you consider the amount of pressure and heat oil has to stand up to.


Ever since that test I've been using Royal Purple in every engine of every vehicle I've owned.  Especially in motorcycles the engine runs noticeably smoother, quieter and even in machines that have noisy valve trains and ticks like a Honda VFR Interceptor there's a distinct smoothing out of internal thrashing.  And contrary to the long-standing myth that synthetics will ruin your wet-clutch, nothing's further from the truth  and in fact even the bike's gearbox becomes smoother.  Ever switched gears in a straight-cut Honda gearbox?  It's solid but clunky, less so with Royal Purple.

I can't make any claims as to greater horsepower since I don't own a dyno nor never had any of my machines on one, but with my last "perfect" car the 2006 Acura RSX Type-S I did notice that I was getting about 10 to 20 more miles per tankful of gas when I ran Royal Purple than without.  And all that translates into better overall protection for the engine, and that's what an oil is really supposed to do.

1 comment:

  1. Be wary, their formulation has changed since the EPA got in their ass. Their additive package that made it much better previously is no longer as good. They still produce it, but you will have to either buy it on amazon or from another remote dealer. Same story with other oil producers, look up the back story on API SL, SM, SN certifications and additive packages. Royal Purple also shears more quickly and isn't as suitable for extended oil change intervals as other synthetics.