Royal purple XPR 10w40 question - 986 Forum - The Community for Porsche Boxster & Cayman Owners

jmatta · 03-19-2010, 05:05 AM

Zero-based viscosities, means naturally less friction. Less friction means MORE horespower.

At the expense of greatly increased engine wear and tear...

Boxtaboy · 03-19-2010, 05:21 AM

Yeah!! According to that link, Mobil 1 makes the most hp!

Seriously though...I guess I'm gonna be the guinea pig here. I have been using Mobil 1 0W-40 on my car since the get go (it's an 01 base with 62k miles on the clock now), with oil changes between 12k-15k mile intervals or every two years (whichever comes first). Strictly by the book (according to the owner's manual). Let's see how long my engine lasts. Knock on wood.

So far, no engine issues whatsover except a broken water pump at 59k miles. I even threw in a bottle of Techron Concentrate about 1200 miles ago, and have not changed the oil yet because it's not time to change the oil according to my schedule.

FWIW, a friend of mine changed his oil (also M1 0W-40 exclusively), on his 2000S every 10k miles until he sold it (still running fine) at over 100k miles on the clock, for a 2006 987S. He also never experienced any engine problems whatsoever.

landrovered · 03-19-2010, 05:26 AM

Quote:

Originally Posted by jmatta

Zero-based viscosities, means naturally less friction. Less friction means MORE horespower.

At the expense of greatly increased engine wear and tear...

This is not correct, wear occurs at startup with cold oil. Zero winter weight is supposed to be less viscous in colder temps, thus reducing friction.

Ten weight winter oil would by comparison have more viscosity which equals less flow, less flow equals more friction.

stephen wilson · 03-19-2010, 05:35 AM

Hmmm... I only see viscosity loss results for 5 of the oils tested? Though they even mention, viscosity loss is not expected in such a short test.

An oil with "middle-to-fair wear particle rating" is one you'd choose, not good or excellent?

Also of note: AMSOIL is rated #1; coincidentally, the website is an authorized AMSOIL dealer!

Low viscosity oils are used for increased H.P. and fuel economy ( reduced friction ) , not for increased engine protection. The site states ( concerning 0 wt. oils ), "for regular street-driven engines, it would be better to look at an oil with a good service interval". Check the descriptions given by any supplier of racing oils, they call 20 wt. oils "qualifying oils", and recommend 30-50 wt. for longer races.

Steve

03-19-2010, 05:52 AM

Bottom line:

The brand of oil chose is like which color is the most popular. All modern synthetic oils are good.

stephen wilson · 03-19-2010, 06:04 AM

I'd agree with that. But why use "good" if you can get "better" or "best"

03-19-2010, 07:57 AM

Better or Best is ALWAYS subjective.

Adam · 03-19-2010, 08:53 AM

I haven't used RP in my Porsche, but I have both the motor oil and gear oil in my Mazda right now. Kinda tough really to know how good an oil is unless you tear down the engine after 100K miles or have a lab and everybody claims their oil is 10X better than the next guys. All I can say is the gear box shifts smoother now and I recommend the gear oil for sure.

941MXVET · 03-19-2010, 09:09 AM

When I first purchased my Boxster, the consencious was that Royal Purple was pretty good stuff, in fact my first oil change was to the Royal Purple 5w-40.

I kept on researching oils and once I learned about polyoester based oils I figured these are what I'm going to use. If your interested in POE (group 5) oils look into Red Line, or Motul 300v oils. Since we live relativly close to a Red Line source, Summit Racing, we went with Red Line.

In the end, it's your car, run the oil your confident in.