fullymatted.
Back to search
Planet-9

Fuel Economy

Add to repair workspace
Open repair workspace
Original source
11 captured repliesPartial discussion capture · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHFuel Economy

Leading reported evidence

Replace o2 sensors if it hasn't been done

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

These cars can be up to 17yrs old now so one other thing you might consider is replacing the O2 Sensors if it hasn't been done.

Original post Read captured discussion
Fuel Economy
Read full discussion summary

Leading evidence: 'Replace o2 sensors if it hasn't been done' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace o2 sensors if it hasn't been done' (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 · 11 captured posts examined · 1 partial discussions

Compare 3 other evidence results

Run will probably see 30ish (yet

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

5spd I my normal mixed use driving is over 24mpg, a long highway only run will probably see 30ish (yet to do a LONG road trip in it).

Original post Read captured discussion
Fuel Economy

Use driving is over 24mpg, a long highway only

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

5spd I my normal mixed use driving is over 24mpg, a long highway only run will probably see 30ish (yet to do a LONG road trip in it).

Original post Read captured discussion
Fuel Economy

Use driving/commuting

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

6spd with my normal mixed use driving/commuting.

Original post Read captured discussion
Fuel Economy
Frequently discussed actions (4)

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

Replace o2 sensors if it hasn't been done

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

These cars can be up to 17yrs old now so one other thing you might consider is replacing the O2 Sensors if it hasn't been done.

Original post Read captured discussion
Fuel Economy

Run will probably see 30ish (yet

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

5spd I my normal mixed use driving is over 24mpg, a long highway only run will probably see 30ish (yet to do a LONG road trip in it).

Original post Read captured discussion
Fuel Economy

Use driving is over 24mpg, a long highway only

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

5spd I my normal mixed use driving is over 24mpg, a long highway only run will probably see 30ish (yet to do a LONG road trip in it).

Original post Read captured discussion
Fuel Economy

Use driving/commuting

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

6spd with my normal mixed use driving/commuting.

Original post Read captured discussion
Fuel Economy
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.

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

  • Planet-9: 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: 20261027T051247Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1Original post

I know, I know, it depends on driving style. But I couldn't help noticing that my fuel burn has gone up a lot in the short time I've owned my new-to-me Porsche . Specs: 987.1 , 64K miles, 3.4 liter engine, manual transmission. 1st tank was 27.1 mpg - all highway 2nd tank was 24.2 - all highway, new water pump installed 3rd tank was 20.7 - city/highway blend, new brakes, oil change 4th tank was 17.3 - city/highway blend Thoughts?

POST 2Original post

You're driving it harder - and they do get excellent highway mileage (and amazing mileage at 50MPH fixed speed, no stops - up to 34-35MPG..)

POST 3Original post

Sounds pretty good! Close what I used to get with my forte 987.1 3.2L MT. I could swear I generally averaged around 23mpg. Looks like you're getting great MPG on the just highway use. BTW - One thing you probably want to routinely check is your tire inflation. Makes a difference, especially over four tanks of gas. YMMV.

POST 4Original post

Looks like mine...usually around 17 - 23 or so..and actually get better MPG than our Acura MDX (my wife has a lead foot and I enjoy listening to VTECH kicking in around 5500 ;-) ) I will try to up shift around 2500 RPM and see if I can get 27

POST 5Original post

I always feel like I'm lugging if I shift below 3K. In fact I think the engine is happier if I cruise in the 3000 to 4000 range. I guess it's how I grew up driving high-winding/ low torque sports cars. Don't really get concerned about MPG unless I'm on a long trip.

POST 6Original post

Thanks for all the replies. 3000 RPM in 6th gear @75 mph seems to translate into about 23 mpg, based on my most recent highway jaunt. I'll calculate again when I refill the gas tank. I don't really care that much about the fuel economy - as long as the lower numbers when my right foot gets heavier are not an indicator of anything wrong.

POST 7Original post

I used to average 21mpg in my 06 Boxster S 6spd with my normal mixed use driving/commuting. Long road trips I would just barely see 26mpg over a tank I think (if the entire tank was highway travel). Now in my 07 Base Cayman 5spd I my normal mixed use driving is over 24mpg, a long highway only run will probably see 30ish (yet to do a LONG road trip in it).

POST 8Original post

These cars can be up to 17yrs old now so one other thing you might consider is replacing the O2 Sensors if it hasn't been done. O2 Sensors can still work within spec but loose sensitivity. I did mine around the 10yr old mark and gained around 10-15% range

POST 9Original post

Good tip. Do you recall if your car was throwing any codes before you replaced it?

POST 10Original post

I usually get 31 to 33 miles per gallon on my Cayman 981 Base on freeway. PDK , Sport on, enthusiastic driving style. I really impresses me. Must be the lightweight and aerodynamics.

POST 11Original post

2.7L with almost 100k, fuel trims look good, healthy engine I'm pretty sure. Usually get 17mpg mountain driving. Highest I've ever gotten was 23ish which was mostly cruising fwy in 4th and 5th gear with some traffic.

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