Rennlist

Higher octane gas leads to carbon build-up???

Add to repair workspace

New repair projectOpen repair workspace

Original source

5 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHHigher octane gas leads to carbon build-up???

Leading reported evidence

Adjust ignition timing

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
actually your 03' BMW will adjust ignition timing to the fuel and, the more advanced the timing is the cleaner it burns meaning less carbon build up which is nothing more than "leftovers" of the quimical reaction.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Read full discussion summary

Leading evidence: 'Adjust ignition timing' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust ignition timing' (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.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

Read captured replies

1 matching discussions · 5 captured posts examined · 0 partial discussions

Compare 4 other evidence results

Run higher octanes

Suggestion or failed attempt

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 · Original poster
are we in reality hurting our Porsche engines by running higher octanes?
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Run right in cities

Suggestion or failed attempt

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
60-70's Jags could never seem to run right in cities.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Use 93 octane

Suggestion or failed attempt

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 · Original poster
we had been using 93 octane from Chevron and he stated that BMW is now recommending ~90 octane b/c the higher octanes are causing alot of carbon buildup and throwing codes
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Use car

Suggestion or failed attempt

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 find it hard to believe) is that probably your wife drives very slowly using only the lower rev range where the combustion is far from perfect due to valve timing and low in-chamber temperatures or uses the car for short trips where the fuel ratio is overly rich.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Frequently discussed actions (6)

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

Adjust ignition timing

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
actually your 03' BMW will adjust ignition timing to the fuel and, the more advanced the timing is the cleaner it burns meaning less carbon build up which is nothing more than "leftovers" of the quimical reaction.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Run higher octanes

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 · Original poster
are we in reality hurting our Porsche engines by running higher octanes?
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Run right in cities

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
60-70's Jags could never seem to run right in cities.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Use 93 octane

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 · Original poster
we had been using 93 octane from Chevron and he stated that BMW is now recommending ~90 octane b/c the higher octanes are causing alot of carbon buildup and throwing codes
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Use 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
- I find it hard to believe) is that probably your wife drives very slowly using only the lower rev range where the combustion is far from perfect due to valve timing and low in-chamber temperatures or uses the car for short trips where the fuel ratio is overly rich.
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

Use supreme(93 octane)

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 · Original poster
recently, when I took my wife's BMW in for service, the service advisor noted that there was alot of carbon buildup and asked if we had been using supreme(93 octane)?
Original post Read captured discussion
Higher octane gas leads to carbon build-up???

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.

5 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: 20261026T165820Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

recently, when I took my wife's BMW in for service, the service advisor noted that there was alot of carbon buildup and asked if we had been using supreme(93 octane)? car is 18 mos old with 14K miles. we had been using 93 octane from Chevron and he stated that BMW is now recommending ~90 octane b/c the higher octanes are causing alot of carbon buildup and throwing codes can this really be true? are we in reality hurting our Porsche engines by running higher octanes?

POST 2Original post

Not really... actually your 03' BMW will adjust ignition timing to the fuel and, the more advanced the timing is the cleaner it burns meaning less carbon build up which is nothing more than "leftovers" of the quimical reaction. The reason for that carbon build up which might be perfectly normal (how did he come to that conclusion? Did he take the head off? - I find it hard to believe) is that probably your wife drives very slowly using only the lower rev range where the combustion is far from perfect due to valve timing and low in-chamber temperatures or uses the car for short trips where the fuel ratio is overly rich. by the way the most effective rev range is near maximum torque.

POST 3Original post

Adviser is just showing his ignorance and confirming that most service advisers know little about the cars they service.

POST 4Original post

That's sounds more like the right answer. In the days of lead gas, that was a normal problem for performance cars. You had to (blow them out) run to high rpms. 60-70's Jags could never seem to run right in cities.

POST 5Original post

Basically she needs to redline it every gear for a couple of days!!!!!!!

This is a source reference. Confirm exact model applicability in the original material.