Oil Bars & Viscosity
05-18-2010, 01:44 AM
#16
Ten years ago, when I owned my 996, there were scattered complaints about valve train clatter at start up from the (then) new water cooled engines, even at non-extreme temperatures. The response to dealers from Porsche, as told to me by my service tech, was to use the 0w-40 oil due to it's ability to get to the affected parts more quickly at start up.
Clearly there are a lot of different opinions on the whole oil issue, and it's been beaten to death before. While there may be benefits emission-wise to using the 0w oil, I've also seen evidence that there are advantages in cold start lubrication as well. I originally reacted to your flat statement that the 0w oil would cause your engine to wear faster. I still disagree. But in normal climates, we're probably talking about tiny differences, hardly worth arguing about.
Bottom line, Porsche filled my car with 0w-40 at the factory, and it's their primary recommended oil. All the opinions and speculation from arm chair experts like us aside, that's enough said AFAIC.
Clearly there are a lot of different opinions on the whole oil issue, and it's been beaten to death before. While there may be benefits emission-wise to using the 0w oil, I've also seen evidence that there are advantages in cold start lubrication as well. I originally reacted to your flat statement that the 0w oil would cause your engine to wear faster. I still disagree. But in normal climates, we're probably talking about tiny differences, hardly worth arguing about.
Bottom line, Porsche filled my car with 0w-40 at the factory, and it's their primary recommended oil. All the opinions and speculation from arm chair experts like us aside, that's enough said AFAIC.
05-18-2010, 12:04 PM
#18
Bottom line for me in a moderate climate? I feel better using the heavier 5w which is just fine to use. For my peace of mind I like the abstract idea of a slightly thicker oil cushioning bearing clearances more when engine is cold. No big deal. Something to talk about, not something to get crazy about
Google around and you get a sense that Porsche (and other mfgrs) is most likely balancing lots of variables, engine longevity vs. good MPG and low emissions are possible conflicts for owners.
05-18-2010, 12:50 PM
#19
Addict
Rennlist Member
Rennlist Member
I was told by a factory mechanic that some of the 997 oil passages are so small that oil heavier than 5 wt will not properly lubricate the engine. He in fact recommended using only 0-40 and not 5-40.
05-18-2010, 01:00 PM
#20
The 0W oil will simply flow better on startup than a 5W oil. This alone should reduce wear. I notice that the 0W40 on a cold startup is showing high oil pressure at idle even when the outside temp is 70 degrees F. I will stay with 0W-40 Mobil-1.
05-18-2010, 01:01 PM
#21
Race Director
05-18-2010, 01:04 PM
#22
The other thing? At least for me, my car will never see 100K miles at the rate I'm driving it so the issue of 0w vs. 5w (and suspicions that engine longevity is at risk) is moot for me anyway! Funny how our brains want to grab onto something and can't let go!
05-18-2010, 01:05 PM
#23
Poseur
Rennlist Member
Rennlist Member
It's funny today how we debate the virtues of 0 vice 5 on the viscosity scale when decades ago it was roughly toss in 30 weight most of the year, and perhaps 20 in the winter, and maybe 40 in a severe summer. Now we're down to 0-5.
05-18-2010, 01:18 PM
#24
Race Director
+1. Was thinking about that earlier in terms of the dipstick vs. digital oil gauge debate and how things have changed, for some things. We trust the computers and sensors in our cars to handle every facet of engine operation, anti-lock brake function, electronic handling and stability control, and on and on, yet people still want to dip a stick in their oil to measure the level. I guess if the digital gauge doesn't work right, it's an issue, but I've had no problem with mine; it seems pretty accurate. At the least, it's consistent, which gives me the proper reference point to decide when I need to add oil. Anyway, just found it amusing.
05-18-2010, 03:23 PM
#25
Race Director
No oil passages in engine smaller than the main/rod and camshaft bearing clearances (on the order of a 0.005" or smaller) and the oil must flow through these just fine or the bearings would be worn out in no time.
With modern engines a large part of their lifetime emissions come after cold start and during warm up. 0W oil mainly to reduce cold engine start friction to help Porsches do better on emissions/CO2 tests. I ran 15w-50 oil early on in my 02 Boxster for 10s of thousands of miles in cold weather and hot and the engine's just fine thank you (with just over 231K miles on it).
Not saying one should run 15w-50 oil -- even I don't anymore cause the 15w-50 oil available now is not the same as it used to be -- but to run 0w-40 for fear the oil will not flow through those mythical tiny oil passages is nonsense.
Generally, the wider the spread between an oil's viscosities the more viscosity improvers the oil maker uses and these can break down over time and lower the oil's viscosity making the oil thinner and less able to protect the engine's moving parts when the oil is hot and under a lot of pressure.
So there's an arqument against 0w-40 and for 5w-40 or even 10w-40.
Even so, I still run 5w-50 oil (Castrol Syntec) in my Turbo and my Boxster. They both get oil changes at 5K miles though. Always have. Always will.
Sincerely,
Macster.
05-18-2010, 08:04 PM
#26
Rennlist Member
He's full of it.
No oil passages in engine smaller than the main/rod and camshaft bearing clearances (on the order of a 0.005" or smaller) and the oil must flow through these just fine or the bearings would be worn out in no time.
With modern engines a large part of their lifetime emissions come after cold start and during warm up. 0W oil mainly to reduce cold engine start friction to help Porsches do better on emissions/CO2 tests. I ran 15w-50 oil early on in my 02 Boxster for 10s of thousands of miles in cold weather and hot and the engine's just fine thank you (with just over 231K miles on it).
Not saying one should run 15w-50 oil -- even I don't anymore cause the 15w-50 oil available now is not the same as it used to be -- but to run 0w-40 for fear the oil will not flow through those mythical tiny oil passages is nonsense.
Generally, the wider the spread between an oil's viscosities the more viscosity improvers the oil maker uses and these can break down over time and lower the oil's viscosity making the oil thinner and less able to protect the engine's moving parts when the oil is hot and under a lot of pressure.
So there's an arqument against 0w-40 and for 5w-40 or even 10w-40.
Even so, I still run 5w-50 oil (Castrol Syntec) in my Turbo and my Boxster. They both get oil changes at 5K miles though. Always have. Always will.
Sincerely,
Macster.
No oil passages in engine smaller than the main/rod and camshaft bearing clearances (on the order of a 0.005" or smaller) and the oil must flow through these just fine or the bearings would be worn out in no time.
With modern engines a large part of their lifetime emissions come after cold start and during warm up. 0W oil mainly to reduce cold engine start friction to help Porsches do better on emissions/CO2 tests. I ran 15w-50 oil early on in my 02 Boxster for 10s of thousands of miles in cold weather and hot and the engine's just fine thank you (with just over 231K miles on it).
Not saying one should run 15w-50 oil -- even I don't anymore cause the 15w-50 oil available now is not the same as it used to be -- but to run 0w-40 for fear the oil will not flow through those mythical tiny oil passages is nonsense.
Generally, the wider the spread between an oil's viscosities the more viscosity improvers the oil maker uses and these can break down over time and lower the oil's viscosity making the oil thinner and less able to protect the engine's moving parts when the oil is hot and under a lot of pressure.
So there's an arqument against 0w-40 and for 5w-40 or even 10w-40.
Even so, I still run 5w-50 oil (Castrol Syntec) in my Turbo and my Boxster. They both get oil changes at 5K miles though. Always have. Always will.
Sincerely,
Macster.
from what i can say - last season my 06 997.1 C2 was suffering badly from valve lifters knocking - after intense auto-x sessions it was obvious hydraulic lifters were completely aerated with no oil in them at all.
this season 15w50 oil plus X51 oil pan remedied that problem completely. I run on r-comps harder than ever swaying car even harder and everything is fine and oil pressure at 250+ degrees is much much better.
I do not know if anyone who is not into autosport needs that oil substitution but for me 15w50 works just perfect.
as of 5w50 oil - i asked several mechanics as well as dealer - it is perfectly fine for 997 cars, winter or summer. when you change the oil you`ll see 5w50 is almost same watery substance as 0w40. 15w50 is way thicker when cold.
05-18-2010, 10:00 PM
#27
Burning Brakes
Its great to see so many experts about oil here on this 997 site...now if we can get them to learn how to change the oil and filter instead of taking the car to the dealership.
I just couldn't help myself
abe
I just couldn't help myself
abe
05-18-2010, 11:14 PM
#28
Then there's the Variocam issue in our engines' valve train where engine oil is used as hydraulic oil.
THAT is why you should NEVER use anything except 0w- and/or 5w-.
Actually that's another reason why you should stick to Mobil1 reccos unless you really know what you are doing.
THAT is why you should NEVER use anything except 0w- and/or 5w-.
Actually that's another reason why you should stick to Mobil1 reccos unless you really know what you are doing.
05-19-2010, 12:32 AM
#29
Race Director
Then there's the Variocam issue in our engines' valve train where engine oil is used as hydraulic oil.
THAT is why you should NEVER use anything except 0w- and/or 5w-.
Actually that's another reason why you should stick to Mobil1 reccos unless you really know what you are doing.
THAT is why you should NEVER use anything except 0w- and/or 5w-.
Actually that's another reason why you should stick to Mobil1 reccos unless you really know what you are doing.
