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Mixing Synthetic Oil Weights: Anyone?

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YOUR RESEARCHMixing Synthetic Oil Weights: Anyone?

Leading reported evidence

Recommend oil at some point (perhaps early

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Suggestion

IIRC a 10w40 oil was a recommended oil at some point (perhaps early on in the 996 life), in fact I think that's what my owners manual recommends.

Mixing Synthetic Oil Weights: Anyone?
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Leading evidence: 'Recommend oil at some point (perhaps early' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Recommend oil at some point (perhaps early' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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Recommend oils are

Suggestion or failed attempt

No successful repair reported for this finding.

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Unsuccessful attempts
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Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I wonder how many people would never look at what the latest recommended oils are but rather just go off of what their owners manual says.

Mixing Synthetic Oil Weights: Anyone?

Replace from one approved oil

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Porsche states that approved oils are miscible, that is when changing from one approved oil to another there's no reason to flush the oil, but when topping up that if possible the same oil be used.

Mixing Synthetic Oil Weights: Anyone?

Replace oil

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Its not as though you wont be changing oil again.

Mixing Synthetic Oil Weights: Anyone?

Replace wifes car

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Buy the other needed to make the oil change for your wifes car.

Mixing Synthetic Oil Weights: Anyone?
Frequently discussed actions (5)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Recommend oil at some point (perhaps early

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

IIRC a 10w40 oil was a recommended oil at some point (perhaps early on in the 996 life), in fact I think that's what my owners manual recommends.

Mixing Synthetic Oil Weights: Anyone?

Recommend oils are

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

I wonder how many people would never look at what the latest recommended oils are but rather just go off of what their owners manual says.

Mixing Synthetic Oil Weights: Anyone?

Replace from one approved oil

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Porsche states that approved oils are miscible, that is when changing from one approved oil to another there's no reason to flush the oil, but when topping up that if possible the same oil be used.

Mixing Synthetic Oil Weights: Anyone?

Replace oil

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Its not as though you wont be changing oil again.

Mixing Synthetic Oil Weights: Anyone?

Replace wifes car

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Buy the other needed to make the oil change for your wifes car.

Mixing Synthetic Oil Weights: Anyone?
Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

12 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • Rennlist: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261027T005001Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Guys, I'm pulling my car out of storage this weekend and will do an oil change. I have 5 quarts of Mobil 1 0W/40 and a few quarts of Mobil 1 10W/40 for my wife's car sitting in garage. Am I asking for trouble by mixing these? No problem to buy a few more quarts of 0W/40, but just wondering if there is an issue with this -- if it's just that I net out at something like 3.5W/40, Not sweat. Any chemistry issues here I am overlooking? Thanks,

POST 2Original post

meh, I might take a look at the chemical make ups on the mobil site to see if these two weights are comparable. If so, mix with reckless abandon

POST 3Original post

It would work fine. http://www.mobiloil.com/usa-english/...aqs.aspx#FAQs5 Can different synthetic motor oils be mixed together? Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils and other synthetic motor oils, should it be necessary to mix them. However, it is important to note that the superior performance of Mobil 1 will be reduced by diluting it in any way.

POST 4Original post

Nope, your figuring exactly right, mix away, wont hurt a thing...

POST 5Original post

Perfectly fine - although one should stick with the same brand, as you are doing.

POST 6Original post

Quotes source post: 9337771

If your wife's car is a Porsche Porsche doesn't recognize 10w-40 as suitable for use in your wife's car. No 10w-40 oil is on Porsche's approved oil list. Porsche states that approved oils are miscible, that is when changing from one approved oil to another there's no reason to flush the oil, but when topping up that if possible the same oil be used. It is up to you but my advise would be to just buy the necessary few quarts of the right oil. You might be able to swap the unopened bottles of 10w-40 oil for the oil you should use. Sincerely, Macster.

POST 7Original post

There is an indy Porsche shop owner who frequents renntech.org and others and is quite knowledgeable with the 986/7 and 996/997. He swears by a certain 10w40 product, castrol I believe and uses it on a lot if not all his customers cars. He says it holds up better under UOA than oils with a wider spread, due to less fillers perhaps. IIRC a 10w40 oil was a recommended oil at some point (perhaps early on in the 996 life), in fact I think that's what my owners manual recommends. I wonder how many people would never look at what the latest recommended oils are but rather just go off of what their owners manual says. It's not like Porsche sends owners updates to the manual in the mail.

POST 8Original post

My manual has 10W40 as an option as well, along with others. Curios though is the exclusion of 0w40 as a option per my manual.

POST 9Original post

Old days a law was made so that mixing oils wouldn't cause problems. For the different weights of oil blends I think you are just doing the same thing they do when making 10w50 or so. In other words enjoy the 5w40 if thats what the blend figures to be

POST 10Original post

On my previous 996 I made a blend using mainly 10W40 or 5W40 synthetic and throwing in quart of motorcycle 20W50 with a paraffin base. This gave a bit of ZDDP to the mix and also is friendly to the lifters and seals. With today's oils you can mix any brand with any other brand and any weight.

POST 11Original post

Quotes source post: 9337771

Just buy yourself the correct amount needed to make your oil change for yours. Buy the other needed to make the oil change for your wifes car. Its not as though you wont be changing oil again. Nothing wasted that way.

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