Best Oil

[riverside986]

Dave Granquist at Redline suggested either of these oils for my 2004 Boxster S. (Live in a really warm inland part of Southern CA.) I've relied on Redline products for a bunch of collector cars. But I'm way short on personal expertise; like a lot of you I often rely on anecdotes of others and the best information I can find. Looking at Redline's technical data, I can see that the viscosity properties of both oils are indeed nearly the same for anything likely to be encountered in this climate.

Just reviewed my original owner's manual (MY 2004) this morning. Interesting read, clearly advises 10W-40 "or heavier," even for synthetics, 10W-40 seems to be the first choice listed for most climates. But wasn't Porsche openly endorsing Mobil 1 0W-40 well before 2004 model year?

Guess we sometimes need to use our own best judgement. Fifteen years back, Mercedes here in the states discouraged use of synthetic oil at the same time they extended the service intervals. They even encouraged dealers to give owners of new cars (including me) a "courtesy" oil change at 1000 miles, tossing out the factory synthetic fill. Result (surprise!) was sludge, eventually they offered extended engine warranty to deal with it.