Sorry to be asking about oil but.....

Seeing that I no longer can find Mobil1 15W-50 (5 quart Jug) at any Wal-Mart down the East Coast, I'm wondering if Mobile1 10W-40 will protect just as well?
I do not put car on track, drive car only in Spring and summer months, from May to September or from 60 degrees to 95 degrees.
Boxster is a 98 with 65,000K.

Thank you

I use M1 or Castrol Edge /Syntek 10w40 on the track.

Else i'd have lousy flow on the street, particularly in the winter. Which, as Marc just pointed out may be worse.

All this talk of 15w50 started with pedro, in S. Fla, on track 50 days a year. For which 15w50 is purrfect.

In fact, did you see my reply below? I even gave you the HTHS spec for m1 10w40 HM. Its quite good, significantly better than 0w40 (which i also gave you).

Grant



Edited 1 time(s). Last edit at 06/01/2011 06:51PM by grant. (view changes)

Thanks Grant. Sorry I had not seen your posting. Can you tell me what the HM is, when you refer to the M1 10W-40.

it means the shear breakdown under High Temperature and High Speed (HT/ HS) exceeds a certain threshold.
that Threshold is ~ 3.6. 15w50 is 4.3 i believe. 10w40 is 4.0 0w40 is substantially less, even though it is "40".

but seriously, for the street 5w30 is just as good! Under cold conditions and moderate driving, maybe better.

Grant

approved viscosity range in any brand of oil?

To the OP: Use a Porsche approved 0w-40, 5w-40 or even a 5w-50 oil.

I run Mobil 1 5w-50 (an approved oil) (in the Turbo and Boxster mainly to simply my oil stocking having to stock only one oil for both cars) here in northern CA and temps range from near freezing in the winter (though here it is June and snow is possible on the highest peaks (< 4K feet) here in the bay area later this week) to over 100F in the hottest days of summer (June of 09 ran into 116F temps driving on 84 coming from Palo Alto to Livermore and around a year ago ran into 118F on I-40 in AZ/CA).

In fact here where I now live and on road trips from CA to points east and back and for a few years when I lived in the mid-west I've run 0w-40 and 5w-40 oils from near 0F to over 100F for thousands of miles with no oil problems ever.

There are huge numbers of Porsches running 0w-40 and 5w-40 approved oils and doing just fine thank you very much.

Or use 5w-30 if you want. It is after all your car and you can run whatever you want. But to run a non-approved oil that is not of the proper viscosity grade for what reason, what is the expected gain...well, my mind is boggled.

Sincerely,

MarcW.

Thank you for your input and expertise Marc. Listening to the opinions here, I feel that, I'd be protected with M1 10W-40 .I don't feel I need the 0W or 5W seeing that cold driving is not a factor.



Edited 1 time(s). Last edit at 06/01/2011 10:19PM by Brasco. (view changes)

40 weight is only required for high temp and pressures. You know that.

Recommendations ,must meet all demands and therefore are compromises, or sometimes over-stated (which is what leads to stupid wide ranges and the use of extra VIIs).

So i stand by it, but of course, i rally recommended a good 5w40 or 10w40 that meets ACEA A3. As i have said about 1M times.

But frankly, i dont give a hoot about Porsche's recommendations. They are made to be idiot proof.

Grant