quick oil question please.
- Thread starter j4mou
- Start date
There's the handbook that was supplied with the car assuming that this was the same worldwide. It has oil viscosity ranges in relation to climate. I'll see if I can scan it and post. Another thing that is less known is that it is alleged that Mobil offered Porsche subsidised or even free oil to promote their 'new' product
(Mobil 1). Even on the racecars that were emblazoned with M1 advertising they were in fact using a straight 50w Shell oil. So don't always believe what you read.
EDIT: Tony beat me to the punch with the chart.
sawood12
New member
Well I don't tend to believe everything I read, in fact I am probably of the most cynical and disbelieving people around, but I did alot of research when I decided on that particular grade of oil canvassing opinions from Porsche dealerships, various specialists, some forums, the oil systems engineers at the company I work for. Finally I decided that 5w40 was probably right, or at least within an acceptable range, for what I use the car for.
The 5w grade gives me excellent cold start protection, which I need as within 2 minutes of setting off i'm accelerating up a slip road onto a busy and fast dual carriageway and sometimes require a quick dab of boost to get into a gap between lorries - though I try my best to minimise any boost action for at least 10 minutes. I also use an ester oil to ensure I get as best cold start protection as possible.
And a 40 grade seems to be a good middle of the road grade. 60 is way too thick in my opinion and for my type of driving i'd rarely get it upto a high enough temp for it's viscosity to be as Porsche engineers intended (and oils that are too thick can put your engine at risk moreso than oils that are too thin), 50 would be fine i'm sure, 40 better, 30 a bit too thin and out of range for our climate according to the Porsche chart. And with modern fully synthetics being so good these days and the efficient oil cooling system of the 944 then a 40 grade should be good for the odd trackday too - though I tend to change the oil pretty soon after a trackday anyway.
Ultimately unless you are way way out of range or are doing something particularly demanding with the car (like racing, alot of trackdays or just driving like a t**t) I don't think there is any detrimental effect of using any of the oils recommended in the chart above within the spec laid out by it. It's all about being considerate about how you use the car, considering mods and choosing the best fit for your driving and above all, investing in a decent quality oil.
Incidentally, none of the specialists or dealerships I spoke to reckoned they had ever seen a knackered engine as a direct result of the owner using the wrong grade of oil. They had seen some from the owner not replacing the oil regularly enough (ten years in one case!!!) but not directly attributable to the incorrect grade of oil. I'm not sure how you'd ever be able to establish that beyond all doubt. Engines give up at a range of lives for thousands of reasons and often the true reason never gets established. Garages and dealerships often don't have the time, the expertise or the resources to conduct a proper engineering investigation to establish the ultimate root cause of the failure. This is my cynicism kicking in!!
One thing I do cringe about is when people talk of choosing thick grades of oil to deal with leaks and to get acceptable oil pressure. That is a sticking plaster measure and though OK for a short period of time the leaks and oil pressure issues really need sorting out. If your car can't run properly on the Porsche recommended grades of oil then, i'm afraid, it needs some attention.
The 5w grade gives me excellent cold start protection, which I need as within 2 minutes of setting off i'm accelerating up a slip road onto a busy and fast dual carriageway and sometimes require a quick dab of boost to get into a gap between lorries - though I try my best to minimise any boost action for at least 10 minutes. I also use an ester oil to ensure I get as best cold start protection as possible.
And a 40 grade seems to be a good middle of the road grade. 60 is way too thick in my opinion and for my type of driving i'd rarely get it upto a high enough temp for it's viscosity to be as Porsche engineers intended (and oils that are too thick can put your engine at risk moreso than oils that are too thin), 50 would be fine i'm sure, 40 better, 30 a bit too thin and out of range for our climate according to the Porsche chart. And with modern fully synthetics being so good these days and the efficient oil cooling system of the 944 then a 40 grade should be good for the odd trackday too - though I tend to change the oil pretty soon after a trackday anyway.
Ultimately unless you are way way out of range or are doing something particularly demanding with the car (like racing, alot of trackdays or just driving like a t**t) I don't think there is any detrimental effect of using any of the oils recommended in the chart above within the spec laid out by it. It's all about being considerate about how you use the car, considering mods and choosing the best fit for your driving and above all, investing in a decent quality oil.
Incidentally, none of the specialists or dealerships I spoke to reckoned they had ever seen a knackered engine as a direct result of the owner using the wrong grade of oil. They had seen some from the owner not replacing the oil regularly enough (ten years in one case!!!) but not directly attributable to the incorrect grade of oil. I'm not sure how you'd ever be able to establish that beyond all doubt. Engines give up at a range of lives for thousands of reasons and often the true reason never gets established. Garages and dealerships often don't have the time, the expertise or the resources to conduct a proper engineering investigation to establish the ultimate root cause of the failure. This is my cynicism kicking in!!
One thing I do cringe about is when people talk of choosing thick grades of oil to deal with leaks and to get acceptable oil pressure. That is a sticking plaster measure and though OK for a short period of time the leaks and oil pressure issues really need sorting out. If your car can't run properly on the Porsche recommended grades of oil then, i'm afraid, it needs some attention.
morris944s2john
New member
I agree, the oilf should be changed at least once a year regardless of mileage.
Scott,
Oil isn't merely a lubricant. It's also there to provide some suspension between the moving parts that are working within very tight tolerances. When you do go to a trackday or drive spiritedly in Summer, the thinner 'snyth' oils will not offer the protection that a thicker grade dino oil will. Nor will they protect you on startup as they will have seeped down into the crankcase. However so long as your happy with what you have and I am aware we are dealing with totally different climates, but even the 20w/50 is good for -10oC. Are you subjected to temps lower than this? Most Porsche dealerships only use what they're told to as well. At least in this country and I'm guessing yours as well.
Oil isn't merely a lubricant. It's also there to provide some suspension between the moving parts that are working within very tight tolerances. When you do go to a trackday or drive spiritedly in Summer, the thinner 'snyth' oils will not offer the protection that a thicker grade dino oil will. Nor will they protect you on startup as they will have seeped down into the crankcase. However so long as your happy with what you have and I am aware we are dealing with totally different climates, but even the 20w/50 is good for -10oC. Are you subjected to temps lower than this? Most Porsche dealerships only use what they're told to as well. At least in this country and I'm guessing yours as well.
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