Why no Porsche recommendation for 5w-30?

[jaj]

There's a simpler way respond to your question, actually. Basically, oil is just another component of the engine, just like the pistons, bearings and connecting rods. It has a job to do.

Just as one manufacturer chooses forged iron con rods while another uses titanium, Porsche chose a 0w-40 oil and Bugatti chose 5w-30. Neither is "better" than the other, they're simply "right" for what they're doing.



Originally Posted By: drkbrent
Originally Posted By: Corvette Owner
The most demanding job for oil in a SI (spark ignition) engine is the oil film strength for the crankshaft. This receives the brunt of the explosions from the cylinders. I suspect that a flat 6 cylinder engine may have more "impact" loading than V8, V10, or V12 engines, since the impacts are 180 degrees opposed.


Now THAT is what I was looking for...this makes sense to me. Thanks for all the responses guys!

 

[JHZR2]

Originally Posted By: Doug Hillary
The Porsche Engineers do place a lot of value on lubricant selection and especially like MB on the use of the manadated viscosities


Yet MB provides viscosity vs temperature charts in their FSMs.

With respect to the highest-level question, why Porsche doesnt have a 30wt, Doug mentioned a number of reasons. However, there is a higher-level basis that I'd imagine might be part of it.

Arent Porsches rear-engine? If so, the airflow characteristics and thus cooling, viscosity characteristics, can be different under operation than a front-engine car. Does the oil pan drop down into the airflow as much? Given the aerodynamics of the car, can there be sufficient heat shedding area for radiator airflow on the back of the car?

While my 135i has high sustained oil temperatures, and can run on a 30wt, the engine can be designed substantially different and still be a straight 6 with twin turbos and whatnot and put out high power density too... with different operating and design characteristics.

Everything in engineering is a trade-off. I have to wonder if Porsche did the trade off of high oil temperatures, extended drains, deposit control and certain tolerance characteristics, and came up with a 40wt... Meanwhile BMW did the same and came up with a 30wt. Both have pros and cons, and the tradeoffs can be worked through and longevity acheived different ways.

Again, I have to wonder if there is an architecture aspect to the approach that drives the use of a 40wt as part of the drivers for the tradespace for selecting the lube specs with common approaches and factors such as those Doug highlighted as major part of the considerations.

 

[Audi Junkie]

Originally Posted By: drkbrent
Originally Posted By: Corvette Owner
People who think they know more than the Car Manufacturer's engineers and designers make me laugh ! Especially Porsche, THEY KNOW what they are doing. Engine tolerances and design mean more than just oil temperature !


Mr. Vette, hope you didn't think my post was insinuating that I knew more than Porsche...far from it!


Get used to it, a typical response you'll get from members who lack the personal knowledge of the subject and defer to authority to carry their argument forward. Those who contend spec oils are the only way to go still fail to offer an explanation of what physical and chemical characteristics other lubes lack.

In no way does a spec oil represent every possibility in the universe. Porsche certainly isn't considering lubes on the market by AMSoil, for instance, which can be as good or better than a spec oil. Spec oil is a minimum requirement, and not the "ideal" people make it out to be.

Anyone who contends there is a vital need to adhere to German specs has a skewed perception of reality. VW 502 has failed time and again.



No need to go into every chronic mechanical failure that adhering to spec oil and owner's manuals has produced over the years.

Obviously, the idealized and sanitized track-side perspective of the test spec lacks real insight.

oem spec lubes for extended oem spec drains is not the dreamride it's claimed to be. Shorter intervals on oil that's specialized for the actual driver's needs is a much better approach.

For the record, I have Edge 5w-30 in my new VW. It cost me nothing and works excellent, but some would argue the old dealer oil with 8000 miles on it is "better" than my new fresh free oil that's nice and thin for my cold starts and short winter drives.

Rock on.

 

[drkbrent]

Originally Posted By: Johnny
I just want to know where around Baton Rouge you can drive speeds like that. Considering the conditions of the freeway that runs through Baton Rouge, anything over 70 would worry me.


Ha, ha! You're exactly right...I-10 to Gonzales is where I hit those speeds...heading north to St. Francisville is a good drive also...wish we had more hills though.

 

[drkbrent]

Originally Posted By: JHZR2
Originally Posted By: Doug Hillary
The Porsche Engineers do place a lot of value on lubricant selection and especially like MB on the use of the manadated viscosities


Yet MB provides viscosity vs temperature charts in their FSMs.

With respect to the highest-level question, why Porsche doesnt have a 30wt, Doug mentioned a number of reasons. However, there is a higher-level basis that I'd imagine might be part of it.

Arent Porsches rear-engine? If so, the airflow characteristics and thus cooling, viscosity characteristics, can be different under operation than a front-engine car. Does the oil pan drop down into the airflow as much? Given the aerodynamics of the car, can there be sufficient heat shedding area for radiator airflow on the back of the car?

While my 135i has high sustained oil temperatures, and can run on a 30wt, the engine can be designed substantially different and still be a straight 6 with twin turbos and whatnot and put out high power density too... with different operating and design characteristics.

Everything in engineering is a trade-off. I have to wonder if Porsche did the trade off of high oil temperatures, extended drains, deposit control and certain tolerance characteristics, and came up with a 40wt... Meanwhile BMW did the same and came up with a 30wt. Both have pros and cons, and the tradeoffs can be worked through and longevity acheived different ways.

Again, I have to wonder if there is an architecture aspect to the approach that drives the use of a 40wt as part of the drivers for the tradespace for selecting the lube specs with common approaches and factors such as those Doug highlighted as major part of the considerations.


Very good food for thought and something I hadn't considered! Thanks!

 

[drkbrent]

Originally Posted By: Audi Junkie
Originally Posted By: drkbrent
Originally Posted By: Corvette Owner
People who think they know more than the Car Manufacturer's engineers and designers make me laugh ! Especially Porsche, THEY KNOW what they are doing. Engine tolerances and design mean more than just oil temperature !


Mr. Vette, hope you didn't think my post was insinuating that I knew more than Porsche...far from it!


Get used to it, a typical response you'll get from members who lack the personal knowledge of the subject and defer to authority to carry their argument forward. Those who contend spec oils are the only way to go still fail to offer an explanation of what physical and chemical characteristics other lubes lack.

In no way does a spec oil represent every possibility in the universe. Porsche certainly isn't considering lubes on the market by AMSoil, for instance, which can be as good or better than a spec oil. Spec oil is a minimum requirement, and not the "ideal" people make it out to be.

Anyone who contends there is a vital need to adhere to German specs has a skewed perception of reality. VW 502 has failed time and again.

No need to go into every chronic mechanical failure that adhering to spec oil and owner's manuals has produced over the years.

Obviously, the idealized and sanitized track-side perspective of the test spec lacks real insight.

oem spec lubes for extended oem spec drains is not the dreamride it's claimed to be. Shorter intervals on oil that's specialized for the actual driver's needs is a much better approach.

For the record, I have Edge 5w-30 in my new VW. It cost me nothing and works excellent, but some would argue the old dealer oil with 8000 miles on it is "better" than my new fresh free oil that's nice and thin for my cold starts and short winter drives.

Rock on.


I agree with what you said! Also, the RLI oils look really good...was about to use them a few years ago, but realized I don't keep cars long enough to justify it! I always say I'll "keep" a car for 4-5 years, but end up getting rid of them after 3!!!

 

[OldBaldy]

Originally Posted By: Audi Junkie
Originally Posted By: drkbrent
Originally Posted By: Corvette Owner
People who think they know more than the Car Manufacturer's engineers and designers make me laugh ! Especially Porsche, THEY KNOW what they are doing. Engine tolerances and design mean more than just oil temperature !


Mr. Vette, hope you didn't think my post was insinuating that I knew more than Porsche...far from it!


Get used to it, a typical response you'll get from members who lack the personal knowledge of the subject and defer to authority to carry their argument forward. Those who contend spec oils are the only way to go still fail to offer an explanation of what physical and chemical characteristics other lubes lack.

In no way does a spec oil represent every possibility in the universe. Porsche certainly isn't considering lubes on the market by AMSoil, for instance, which can be as good or better than a spec oil. Spec oil is a minimum requirement, and not the "ideal" people make it out to be.

Anyone who contends there is a vital need to adhere to German specs has a skewed perception of reality. VW 502 has failed time and again.

No need to go into every chronic mechanical failure that adhering to spec oil and owner's manuals has produced over the years.

Obviously, the idealized and sanitized track-side perspective of the test spec lacks real insight.

oem spec lubes for extended oem spec drains is not the dreamride it's claimed to be. Shorter intervals on oil that's specialized for the actual driver's needs is a much better approach.

For the record, I have Edge 5w-30 in my new VW. It cost me nothing and works excellent, but some would argue the old dealer oil with 8000 miles on it is "better" than my new fresh free oil that's nice and thin for my cold starts and short winter drives.

Rock on.


I'd suggest that engine wear is only ONE of MANY critical concerns for the manufacturer to consider in their oil spec. To you or I, it may be the MOST critical, but that doesn't mean there are not many others (as we well know) that manufacturers have to consider and develop test protocols for.

Personally, ONLY spec oils will be used in my motors. I have little to zero reason to use anything else, from my own UOA results. YMMV.

 

[Audi Junkie]

Redline, AMSoil, RTS, SynPower Racing, BradPenn...?

 

[Audi Junkie]

http://en.wikipedia.org/wiki/Appeal_to_authority


Argument from authority (also known as appeal to authority) is a fallacy of defective induction, where it is argued that a statement is correct because the statement is made by a person or source that is commonly regarded as authoritative. The most general structure of this argument is:

1. Source A says that p is true.
2. Source A is authoritative.
3. Therefore, p is true.

This is a fallacy because the truth or falsity of a claim is not related to the authority of the claimant, and because the premises can be true, and the conclusion false (an authoritative claim can turn out to be false). It is also known as argumentum ad verecundiam (Latin: argument to respect) or ipse dixit (Latin: he himself said it).

 

[tonycarguy]

A better question is: Why does the Veyron use 5w30? High performance European cars tend to use 40 weights and thicker (Ferrari, Lambo, Porsche), so you might ask why the Veyron goes against this?

 

[rshunter]

Originally Posted By: tonycarguy
A better question is: Why does the Veyron use 5w30? High performance European cars tend to use 40 weights and thicker (Ferrari, Lambo, Porsche), so you might ask why the Veyron goes against this?


Because 30wt oils aren't unusual for Volkswagen AG products.

 

[drkbrent]

Originally Posted By: tonycarguy
A better question is: Why does the Veyron use 5w30? High performance European cars tend to use 40 weights and thicker (Ferrari, Lambo, Porsche), so you might ask why the Veyron goes against this?



Very true...ok, so why?

 

[Audi Junkie]

5w-30 is to Europe what 5w-20 is the the USA.

 

[virginoil]

Originally Posted By: Audi Junkie
5w-30 is to Europe what 5w-20 is the the USA.


You could say the same for Australia.

5w30 is about the thinnest grade I have come across over as std recommendation by OEM's.

 

[BMWTurboDzl]

Originally Posted By: tonycarguy
A better question is: Why does the Veyron use 5w30? High performance European cars tend to use 40 weights and thicker (Ferrari, Lambo, Porsche), so you might ask why the Veyron goes against this?



It's because the Veyron engine is just 2 VW W8's stuck together. (hehe)

 

[drkbrent]

Originally Posted By: BMWTurboDzl
Originally Posted By: tonycarguy
A better question is: Why does the Veyron use 5w30? High performance European cars tend to use 40 weights and thicker (Ferrari, Lambo, Porsche), so you might ask why the Veyron goes against this?



It's because the Veyron engine is just 2 VW W8's stuck together. (hehe)


Ha!

 

[riggaz]

Originally Posted By: drkbrent
I have an '09 Porsche 911 Turbo that recommends 0w-40 or 5w-40. Why is there no 5w-30 recommendation? The Bugatti Veyron comes with Castrol Edge 5w-30 in it's veins, and several Mercedes V-12, turbo charged engines have the 5w-30 also. I run Lubrication Engineers 8530 (5w-30) in my Porsche and have complete confidence in it. I guarantee there's nothing special about the Porsche engine compared to the Bugatti!! Why does my '10 Audi A8 also have the 5w-40 recommendation? I can't see what significant advantage 5w-40 has over 5w-30...and if there were, why wouldn't the massively expensive and technologically advanced Bugatti have it from the factory? It seems all those extreme, expensive, high-horsepower engines would have the same oil in them, especially since they're all owned by the Volkswagen group!? Thanks for the responses!


I would be careful comparing oils from different engine designs to each other because they have different operational requirements bud. A Ferrari Enzo requires 10w-60 oil but put that in your Passat for a variable service and there would be a few unhappy faces after 20k miles. The flat six Porsche engine is no relation to the W16 Veyron engine so don't be too surprised that they require different engine oils. Stick to the Porsche A40 spec 0w-40 or 5w-40 for your engine.

 

[Luxter]

Porsche aerodynamics have some to do with it just like someone before mentioned. The 911 engines in general are water AND oil cooled not just water cooled. They run hotter (oil) than most other cars and quite larger oil sumps than other cars. We are talking +9L of oil and some 24L of water.
In the past (early 2000’s) a range of oils were acceptable by Zuffenhausen ranging from 0w40 through 5w40, 10w40, 5w50 and 10w60. It was the 2000’s that P streamlined for unknown reasons their approach to oils to ?w40 and just one 5w50. Many oils were added/removed from the A40 list. There are still some 90 – 100 oils that get the blessing.
The IMS failure has little to do with motor oil selection, the failing bearing is a sealed type bearing and therefore not lubricated by engine oil. The IMS affected cars are M96 and M97 family 996, 997, Boxster and Cayman so Turbos and GT3 cars are excluded.
Porsche is primarily concerned with piston cleanness (10/10 on their scale) and engine wear (7/10), see the spider graph for A40, that probably explains why thicker than 5W40 oils are removed from the list. Someone more educated may explain how thinner oils clear piston/ring area faster than heavier grades.
That still does not explain why, or why, M1 5W50 in spite of its weight is still approved.
From my experience 997 runs quieter on 5W40 oil than 0W40, produces more oil pressure at idle fully warmed up compared to 0w40. I have reasons to believe that quiet engine is a happy engine.
More importantly there is an issue of cyl. #6 scoring on 997 3.6 and 3.8 L engines that is related to overheating both coolant and oil, or shall I say, exceeding what oil can handle in bore #6 in particular. More info on British Hartech. Long article, but well worth reading. It sheds more light on why 160*F T-stat may be beneficial for those engines.
I would not run any ?W30 oil in P-car. Regardless if Veyron or Vette or any other hi-perf car is OK with it.
Question remains if non A40 oils are better suited for the job. In my opinion (supported by a number of opinions from various sources that I shared on this forum) 10W40 may be a better choice if you do not lease your car and plan to keep it for years to come.
(Putting my flame suit on… I can only imagine all Nissan Sentra owners sharpening their pencils now) YMMV.

 

[Luxter]

Originally Posted By: NewYorkBuck
I have a 2004 911 turbo. The factory initally recommended 0W-40, but lately bc of intermediate shaft issues, many are going to either M1 TDT 5W-40 or 5W-50.

I have done also myself. The difference in engine noise w TDT vs 0W-40 is not slight. Must be the extra ZDDP I suppose.....

You don't have to worry about IMS failure in your turbo. There is no bearing to fail.
Oil as I mentioned does not have any influence on IMS failure, it may be used as possibly early indicator. More so cam deviation are better indication.
Engine noise & ZDDP - I can fully sympathize with.

 

[Luxter]

Originally Posted By: Doug Hillary
Hi,
Corvette Owner - You said this:
"People who think they know more than the Car Manufacturer's engineers and designers make me laugh !"

I feel the same about this as you do - and I have worked as, for, with, and around such people since 1957! In the US, UK and Germany too!!


That’s really shallow approach to the issue Doug and C-Owner. I don’t believe people flock to BITOG to show off their wisdom and proof anybody wrong or idiot or whatever. I don’t believe most of us come here to be trolls and derail others posts. Last I checked it is still democracy and we have privilege to express our opinions.
As to questioning Manuf. Engineers, their recommendations cover really broad territory of all possible conditions that their cars being used. And “People who think know more” are trying to select what’s the best for them and actually care to share their opinion with others. In fact Doug you are not any different that that since you use Delvac in your P-car that is not on A40 list, so please follow your own advice.
On other hand I feel that there are many posters that have +2-3,000 and more posts here however their cumulative value added to this forum is relatively minor and attitudes that are just downright embarrassing. I wish people put some thought into their posts and honestly ask themselves if that very post actually adds any value to the dispute.