Using 5W-40 oil instead of 0W-40
11-03-2021, 12:44 PM
#151
Rennlist Member
Thread Starter
While we're resurrecting this thread, I'm curious where one might find a CURRENT LIST of A40 approved 5W-40 oils, not one from 2019 since it seems that oil brands come on and off the list of A40 approved oils list.
Also, What's the deal with C40?. I know that at some point Porsche backdated the approved oil use of A40 for all vehicles dating back to the 80s. I'm wondering if Porsche will issue a similar recommendation with C40. Anyone have any ideas on this? I know there have been other threads on this previously.
Also, What's the deal with C40?. I know that at some point Porsche backdated the approved oil use of A40 for all vehicles dating back to the 80s. I'm wondering if Porsche will issue a similar recommendation with C40. Anyone have any ideas on this? I know there have been other threads on this previously.
11-03-2021, 01:29 PM
#152
Rennlist Member
The latest A40 (5/2021) and C40 (8/2021) Porsche docs are attached
Last edited by bb964; 11-03-2021 at 01:35 PM.
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11-03-2021, 01:46 PM
#154
Rennlist Member
11-03-2021, 02:21 PM
#155
Rennlist Member
Thread Starter
This is SUPER helpful @bb964 .
Curious as I look at the C40 sheet, it states
Model Year: As of 1984 up to 2020
Vehicle Type: All Porsche vehicles, up to and including MY 2020, for which Porsche C40 engine oils are allocated.
The part that confuses me is that it includes vehicles from 1984 to 2020, but then it says "for which Porsche C40 engine oils are allocated". Trying to figure out if the specified year range makes it ok for the 991.2, or if the secondary statement specifically excludes the 991.2 (and prior models).
Then it also states this...
All engine oils approved by Porsche can be mixed provided they are of the same Porsche oil specification. This means that it is not necessary to flush the engine when the oil is changed if another type of oil is used
So does this mean that you shouldn't switch between A40 and C40 without completely flushing the engine?
Sorry if my questions seem ignorant. I'm really just a novice DIYer that has learned everything from YouTube and forums like these
In essence, I'm just trying to figure out if it makes sense to transition to C40 as potentially the newer/better alternative and that can potentially replace A40 or if it's A40 always as that's what the original manual states.
Curious as I look at the C40 sheet, it states
Model Year: As of 1984 up to 2020
Vehicle Type: All Porsche vehicles, up to and including MY 2020, for which Porsche C40 engine oils are allocated.
The part that confuses me is that it includes vehicles from 1984 to 2020, but then it says "for which Porsche C40 engine oils are allocated". Trying to figure out if the specified year range makes it ok for the 991.2, or if the secondary statement specifically excludes the 991.2 (and prior models).
Then it also states this...
All engine oils approved by Porsche can be mixed provided they are of the same Porsche oil specification. This means that it is not necessary to flush the engine when the oil is changed if another type of oil is used
So does this mean that you shouldn't switch between A40 and C40 without completely flushing the engine?
Sorry if my questions seem ignorant. I'm really just a novice DIYer that has learned everything from YouTube and forums like these
In essence, I'm just trying to figure out if it makes sense to transition to C40 as potentially the newer/better alternative and that can potentially replace A40 or if it's A40 always as that's what the original manual states.
Last edited by Tier1Terrier; 11-03-2021 at 02:24 PM.
11-03-2021, 02:51 PM
#157
Rennlist Member
Thread Starter
Interesting because as I look carefully at the two different lists, Liqui Moly Top Tec 4110 5W-40 appears on both of them but on the Liqui Moly website it only shows C40 on the label (and not A40). What does one make of that? Could it be that the manufacturer hasn't updated their website and/or label or am I misunderstanding the bulletin?
https://products.liqui-moly.us/top-t...e-5w-40-1.html
https://products.liqui-moly.us/top-t...e-5w-40-1.html
11-03-2021, 09:30 PM
#158
Thanks for sharing. Greatly appreciated.
11-03-2021, 09:31 PM
#159
11-03-2021, 09:35 PM
#160
This is SUPER helpful @bb964 .
Curious as I look at the C40 sheet, it states
Model Year: As of 1984 up to 2020
Vehicle Type: All Porsche vehicles, up to and including MY 2020, for which Porsche C40 engine oils are allocated.
The part that confuses me is that it includes vehicles from 1984 to 2020, but then it says "for which Porsche C40 engine oils are allocated". Trying to figure out if the specified year range makes it ok for the 991.2, or if the secondary statement specifically excludes the 991.2 (and prior models).
Then it also states this...
All engine oils approved by Porsche can be mixed provided they are of the same Porsche oil specification. This means that it is not necessary to flush the engine when the oil is changed if another type of oil is used
So does this mean that you shouldn't switch between A40 and C40 without completely flushing the engine?
Sorry if my questions seem ignorant. I'm really just a novice DIYer that has learned everything from YouTube and forums like these
In essence, I'm just trying to figure out if it makes sense to transition to C40 as potentially the newer/better alternative and that can potentially replace A40 or if it's A40 always as that's what the original manual states.
Curious as I look at the C40 sheet, it states
Model Year: As of 1984 up to 2020
Vehicle Type: All Porsche vehicles, up to and including MY 2020, for which Porsche C40 engine oils are allocated.
The part that confuses me is that it includes vehicles from 1984 to 2020, but then it says "for which Porsche C40 engine oils are allocated". Trying to figure out if the specified year range makes it ok for the 991.2, or if the secondary statement specifically excludes the 991.2 (and prior models).
Then it also states this...
All engine oils approved by Porsche can be mixed provided they are of the same Porsche oil specification. This means that it is not necessary to flush the engine when the oil is changed if another type of oil is used
So does this mean that you shouldn't switch between A40 and C40 without completely flushing the engine?
Sorry if my questions seem ignorant. I'm really just a novice DIYer that has learned everything from YouTube and forums like these
In essence, I'm just trying to figure out if it makes sense to transition to C40 as potentially the newer/better alternative and that can potentially replace A40 or if it's A40 always as that's what the original manual states.
These are great question. Thanks
11-03-2021, 09:57 PM
#161
Intermediate
My dealer changed my 2014 991.1's oil annually using Mobil 1 0W-40 for my car's first 6 years. I changed it myself in 2020 and 2021 using Castrol Edge 5W-40 A3/B4 Euro Car which is a Porsche A40 oil.
11-03-2021, 11:45 PM
#162
RL Community Team
Rennlist Member
Rennlist Member
C40 is low SAPS. A40 is full SAPS. Don’t use C40 oil unless your car MUST use it. A40 for you buddy. Forget about C40.
While we're resurrecting this thread, I'm curious where one might find a CURRENT LIST of A40 approved 5W-40 oils, not one from 2019 since it seems that oil brands come on and off the list of A40 approved oils list.
Also, What's the deal with C40?. I know that at some point Porsche backdated the approved oil use of A40 for all vehicles dating back to the 80s. I'm wondering if Porsche will issue a similar recommendation with C40. Anyone have any ideas on this? I know there have been other threads on this previously.
Also, What's the deal with C40?. I know that at some point Porsche backdated the approved oil use of A40 for all vehicles dating back to the 80s. I'm wondering if Porsche will issue a similar recommendation with C40. Anyone have any ideas on this? I know there have been other threads on this previously.
The following users liked this post:
the_buch (11-04-2021)
11-04-2021, 05:36 PM
#163
Rennlist Member
Thread Starter
Could you help me understand why for example Liqui Moly Top Tec 4110 5W-40 appears on both of the above referenced technical bulletins under A40 spec and C40 spec? Based on what you're saying which I have no doubt is correct, how can one oil fall on both lists? Also keep in mind that on the Liqui Moly website, that oil only shows the C40 spec printed on the containers (stock image).
11-04-2021, 06:05 PM
#164
RL Community Team
Rennlist Member
Rennlist Member
Thanks, @Jack F !
Could you help me understand why for example Liqui Moly Top Tec 4110 5W-40 appears on both of the above referenced technical bulletins under A40 spec and C40 spec? Based on what you're saying which I have no doubt is correct, how can one oil fall on both lists? Also keep in mind that on the Liqui Moly website, that oil only shows the C40 spec printed on the containers (stock image).
Could you help me understand why for example Liqui Moly Top Tec 4110 5W-40 appears on both of the above referenced technical bulletins under A40 spec and C40 spec? Based on what you're saying which I have no doubt is correct, how can one oil fall on both lists? Also keep in mind that on the Liqui Moly website, that oil only shows the C40 spec printed on the containers (stock image).
11-05-2021, 04:07 PM
#165
Rennlist Member
I've read that on countless car and motorcycle forums. These recommendations are based on what? Some scientific paper with plenty of testing? LOL Just use what Porsche recommends. In forty-seven years of vehicle ownership, I have yet to have an engine or oil related failure. All the info can be found in Owner's Manuals.
By the way, the "40" is what it is when the engine oil is at 100C or 212F, roughly what your oil temperature is unless you are on the track or stuck in traffic. The 0W or 5W...who cares. The thinner the oil, the faster it gets to where it is needed.
By the way, the "40" is what it is when the engine oil is at 100C or 212F, roughly what your oil temperature is unless you are on the track or stuck in traffic. The 0W or 5W...who cares. The thinner the oil, the faster it gets to where it is needed.
Last edited by IXLR8; 11-05-2021 at 04:12 PM.