Choice of oil

[Brucelee]

Wondering who uses what when changing your own (Dealer s/b using Mobil 1 0-40). Candidly, here in SOCAL, I still use 15-50 Redcap Mobil 1.

Any others of choice and if so, why?

[Tool Pants]

I still use Mobil 1 15W-50 and it is the only oil my 1997 Boxster has seen after it was first changed many years ago. Same was used by my dealer for years until they switched when Porsche issued a bulletin for 0W-40. Northern California.

[Brucelee]

I had an oil engineer who worked for Mobil tell me he would not put 0-40 in his wife's sewing machine. Strong words indeed.

I am with you on the Red Cap.

[donv]

15-50 for warm weather only use in New England. I was uncomfortable with trusting the additives to fully protect the engine at high temp and it was silly to run the risk when I seldom drive the car at low temp (so I don't need the 0w- part). I had read an article claiming that the only way they get a wide spread on the cold/hot viscosity is through the additives, which are subject to breaking down. Once they do, you're drifting to the lower end of the rating for the "resulting" protection when hot.

[Brucelee]

As I understand it, as oil ages, its ability to handle the higher vis needs degrades. Ergo, a 0-40 weight oil will fairly quickly devolve towards 0. Apparently, this happens MUCH more slowly with a 15 or 20W-50 oil.

Hence, my comments about the redcap for the warmer climes.

[Ad Sach]

Redline oil (unique formula) uses NO additives and is not petroleum based like other synthetics, so it basically doesn't degrade as much as get too dirty to continue using.

[Fletcher]

I bought some Royal Purple to use at first oil change 10x40. I have used it a couple of times now with success. It was ultimately recommended to me by Randy Webb @ webbmotorsports. It was the only oil he has used that consistently made 1-2 h.p. repeatable on the dyno. He is a big redline fan btw.

[Tool Pants]

Originally posted by Brucelee
I had an oil engineer who worked for Mobil tell me he would not put 0-40 in his wife's sewing machine. Strong words indeed.

I am with you on the Red Cap.

So that is why after all the oil changes we have done over the years the car sounds like a sewing machine after an oil change.

99% of the people have no clue about the reference to the red cap.

We put in what the owner bring to our work on cars days. Every brand and weight. Costco to Redline, to Kragens. After over 5 years of Boxstering I have not heard of any engine issue related to oil. Plus, Porsche changes the approved list every few months.

For you oil freaks, there is a message board.

http://theoildrop.server101.com/cgi/ultimatebb.cgi

[Brucelee]

Sorry, Redcap is referring to Mobil 1 15W-50. This is the synthetic that was used by Porsche in the Box and 996 until they switched to recommending the Black Top, also know as Europeon brand 0W-40.

As you can see, the base stock vis of the two oils is very different and hence, the concern I have about running Black Top in hot weather.

You will get better gas mileage with the Black Top which is why many manufacturers go that route. However, for M cars, BMW recommends Castrol 20-60, so they must have some concerns about how well the lighter oils hold up in performance autos.

[Tool Pants]

The caps.

[Bethencorp]

Tool Pants

The question is which one do you use? I am now in the winter months where I live and there is snow on the ground. My car was just serviced and they used 0W-40, black cap. Are you suggesting that I change the oil to 15W-50, red cap when the summer comes? Why would Porsche reccomend 0W-40 for all seasons if they don't believe it can hold up? I could not see them wanting engine failures on their doorsteps every time they turned around?

Educate me on this if you would!

[Tool Pants]

I and some other local Boxster/996 owners still use 15W-50 which was approved for many years, but no longer. I have a January 1997 and it work for me. I am in California and our winter is rain.

I have been Boxstering for almost 6 years. Porsche has changed the factory fill at least twice that I can remember, which means nothing to me but is important to some owners. Porsche sells the cars around the world. Porsche issues a new oil bulletin about once a year with a list of approved oils. Their bulletins do not match the weights in the owners manual. When Porsche issues a new bulletin Porsche does not say why there has been a change from the prior bulletin.

In fact, not too long ago there were serveral conventional mineral oils on the approved list. Now it is just synthetics.

I am not privy as to why to why Porsche switched to 0W-40. We guessed at one time the lighter weight oil was to reduce lifter noise at start-up, better fuel economy, or because it had a different approval.

I would keep your 0W-40 since that is what Porsche says at this point in time to use.

If this link works here is the most recent bulletin I have.

http://home.jps.net/~mjlopez/images/Box%20oil%20world%207-9-04.pdf

http://home.jps.net/~mjlopez/images/Box%20oil%20world%207-9-04.pdf

[Adam]

Wow, I didn't know they made 0w20. That must for the cars near the polar ice caps. 0W40 here. Spring, summer, and Fall driving in IL.

[Brucelee]

The 0-20 is only used by Ford I believe. What are they thinking?

In warm temps, I think the 15-50 is the deal. In cold climes, I think I would go with Castrol Syntec 5-50. If I lived in Palm Springs in summer, I would go with 20-60 Castrol.

And of course, who really knows?

[Adam]

I drive my car in temps between 50-85 degrees the majority of the time. I believe 0w40 is ideal for owners that live in varied climes and don't like to change their oil every 3 mo for hot/cold weather. 15w50 probably wouldn't be to great at 50-60 degrees. It's all about the best compromise really.