Newbie - Cooling/Temp Question

[deliriousga]

Originally Posted by RandallNeighbour

I will try 15w-50 next oil change.

Mmmmmmm. Ours runs soooo much smoother with 15w-50 Mobil 1 in the hot GA temps. The 10w-30 shows a top outside temp of 90 degrees in the AllData manuals, easy to reach here and even easier over there in Houston. Try it, you'll like it!

[RandallNeighbour]

Right now I am using the "Porsche approved" viscosity of 0W-40. Do you recommend I do an oil change to 15W-50 before I make my long hot trip through the desert from Houston to San Jose and back through Las Vegas and the Grand Canyon?

[deliriousga]

0w40 is not listed. The temp ranges were under the 928 AllData info. Mine was built before this and filled with 10w40 at the dealer, but here's what AllData says about Boxster:

Begining January 24, 2001, all Porsche vehicles are now factory filled with 0w/40 Mobil 1 engine oil.

Engine oils in the viscosity 0w/40, 5w/40 and 5w/50 must correspond to the ACEA A3 specifications

Sorry, I don't have my manual here or I'd look it up. Look in the owner's manual to see the chart of oil weights and what temp ranges they can handle. 0w40 may be able to handle a wider range of temps than other weights.

I checked the 15w50 bottle and it does correspond to the ACEA A3 specs. I also went to the Mobil 1 website and used its' oil selector and it recommended 0w40. The odd thing is I tried it for both cars and it asked me for the outside minimum temp on the 928 but not on the Boxster.

Maybe Brucelee or Tool Pants can shed some light on the oil deal. We may need to create a thread so people know what we're talking about and can chime in.

Off to change the fan! Have a fantastic day everyone!

[Brucelee]

Porsche currently recommends 0-40 Mobil for all temp ranges.

Prior to that oil being made, they routinely recommended and used 15-50 M1.

Based on the characteristics of the two oil, I would personally use the 15-50 in the hotther climes that we have been discussing. For other climes (say along the coast here in SD), the 0-40 would be fine IMHO. For racing, there is no question that 15-50 is the oil to use.

It is important to note that of the two oils, the newer version of the 15-50 is actually the only one that Mobil will "warranty" to last up to 15K miles.

As you know, Porsche specifies a 20K oil change for the 987. Wonder how they reconcile this within the company?

Hmmmm!

[Tool Pants]

Over the 6 years I have been Boxstering Porsche has changed the recommended oils over, and over, and over again. In fact back then there were approved conventional mineral oils.

Back then in my area the local owners and the dealers used 15W-50, which was approved back then. That is the only weight my 1997 has seen. Then Porsche switched to 0W-40 but did not say why. I assumed it was because some owners complained about lifter noise when starting a cold car.

I am an old fart and where I live I cannot imagine using a 0 oil since in all the cars I have owned I never used 0, and I have never lived in Alaska. Old habits are hard to die. So I and some of the other older local owners continue to use 15W-50 while others have switched to 0W-40.

At our work on cars days people show up with all sorts of nonapproved oils and we put them in and there have been no problems.

I have never heard of any type of engine damage cause by the weight of oil.

[Brucelee]

In San Jose, I would certainly stick with the 15-50.

If I lived in Chicago or Boston, the 0-40 would certainly be the way to go in winter.

The heavier oil will create more friction and heat but that is not an issue in warmer climes.

Using 15-50 in a Chicago winter would be ill advised for sure.