I'm starting to use 10W-40 as I find the oil comsumption is lower.

 

You should never blend different oils. They can have a chemical reaction as they are synthetics and they do not mix. I have been reading about that for many years. Your P-car manual should let you know what oil to use at what temps. I prefer the "old" mobile 1 that still has ZDDP. The High mileage one. The EPA will not give the starburst, because they say ZDDP clogs cats, but the wear protection is great. I also love Royal Purple, best wear protection, but it breaks down a bit faster over time.

 

DT40 Joe Gibbs Racing, LNE and Flat Six Innovations recommended. It's made specifically for the Porsche engine.

 

+1 for DT-40.

 

wow, very cool. I haven't visited 6speed for some time, and I'm taking a look around and here we are in the midst of the continuing and neverending OIL WARS. Hoo-rah. Semper Fi. Let's rock and roll like we did last summer, baby. ok, enough of that. Red Line 10-40, my friends. There, I'm in, locked and loaded. Burke, what do you need in your car at all times? Right, a spare Red Line bottle and a Springfield EMP.

 

Well, I was off work for a month from an injury about 2 years ago and studied oils the entire month. It is confusing, mostly because the EPA is jerking oil companies around. Lots of false data out there too. I have seen hundreds of tests and oil analysis data on uncountable numbers of oils. Many companies make deceiving claims, but as I compiled all the data from tons of hours of study, I switched from my beloved Royal Purple, to Mobil 1 High mileage. I do think that Royal Purple is the best oil for cars that don't sit around for long, but I decided to change after all that I learned. I own many cars that sit around most of the time, so I decided to pick an oil that has been tested and proven effective, and has a bit longer life. I wrote tons of info on here with links to everything about 2 years ago. The discussion went on for over 50 pages. It is confusing, but I feel confident with my choice. As far as weight goes, use what the manufacturer recommends for your climate. I have a different weight oil for 5 cars... Crazy. I really love Royal Purple though, because when I rebuilt my 300ZXTT with 140K miles on it, My machine shop guru said that he had never seen an engine with so little wear with that mileage. I had no brown stains on anything. The metal parts were all super smooth and shiny. My machine guy was confused why I was doing a rebuild, but I just needed a stronger bottom end so I can push my RWHP to close to 600. The stock internals are only good for about 500-550HP. That really made me a believer in Royal Purple. That car only holds 4 quarts with a larger oil cooler. Under 4 quarts stock, so that oil was working hard and staying really hot in Tucson, AZ. Virtually no wear. I'm sure if you want more info, search past posts. Tons of info on here with real studies and real tests. The discussion was on the 996TT forum.

 

Motul Competition 300 15-50

 

oil wars are great. lots of information out there.
I use Red Line as recommended by my mechanic, and noticed right away that the engine ran 2-3 degrees cooler. Also ok for your cats, should not burn them out.