fullymatted.
Back to search
Rennlist

Speedometer/odometer accuracy

Add to repair workspace
Open repair workspace
Original source
13 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHSpeedometer/odometer accuracy

Leading reported evidence

Adjust tire size

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 · Original poster

Is there a fix for this, aside from adjusting tire size?

Speedometer/odometer accuracy
Read full discussion summary

Leading evidence: 'Adjust tire size' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Adjust tire size' (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 · 13 captured posts examined · 0 partial discussions

Compare 2 other evidence results

Set speed and tag along behind

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

Or do what I did - get a buddy or partner to drive their car at a set speed and tag along behind.

Speedometer/odometer accuracy

Set their speed at a nice round number

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

I notice that when cruising on the freeway, I'm travelling at the same speed as other cars/drivers, who have presumably set their speed at a nice round number with cruise control.

Speedometer/odometer accuracy
Frequently discussed actions (3)

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

Adjust tire size

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

Is there a fix for this, aside from adjusting tire size?

Speedometer/odometer accuracy

Set speed and tag along behind

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

Or do what I did - get a buddy or partner to drive their car at a set speed and tag along behind.

Speedometer/odometer accuracy

Set their speed at a nice round number

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 notice that when cruising on the freeway, I'm travelling at the same speed as other cars/drivers, who have presumably set their speed at a nice round number with cruise control.

Speedometer/odometer accuracy
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.

13 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: 20261027T173940Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

My speedometer seems to read 7-12 mph higher than actual speed. From reading through previous posts, sounds like a tire size issue. My concern is that this is also affecting my mileage. Miles are pouring on at a much higher rate than what I'm actually driving. A 10 mile trip is registering as closer to 15-17. You can see how that will add up quickly. Is there a fix for this, aside from adjusting tire size? Anyone else notice similar situation? Thanks

POST 2Original post

Look in tech area, 996 faq, troubleshooting, #8.

POST 3Original post

IF that is true (50%+) inaccuracy, take it back to the dealer and have them look at it. You cannot effect the odometer that much with tires.....no matter what size you are running. My guess is that your calculations are way off.

POST 4 / ORIGINAL POSTEROriginal post

Woody, I'm not finding the post you're referencing. What is it titled?

POST 5Original post

Sorry, not a post, it's in the Tech area of the rennlist homepage, I'll copy and paste. The speedometer is reported to be off (high) by around 10% in some cars. This affects not only speed reported but mileage, which can be significant over the length of a lease. The good news is that there is a software fix for this which should be available at all dealerships. Or do what I did - get a buddy or partner to drive their car at a set speed and tag along behind. I notice that when cruising on the freeway, I'm travelling at the same speed as other cars/drivers, who have presumably set their speed at a nice round number with cruise control. There you go.

POST 6Original post

You can calculate your exact speed within 1% using your rear tire size and your engine speed, gear ratio and final gear.

POST 8Original post

Rather than doing it long hand, try this calculator. http://www.wallaceracing.com/calcmph.php

POST 10 / ORIGINAL POSTEROriginal post

Thanks guys...I'll look into this software at the dealer.

POST 11 / ORIGINAL POSTEROriginal post

Hmmm, dealer doesn't seem to know of a software fix. Anyone else have any experience with this?

POST 12Original post

Check this link to verify error. Speedo is off

POST 13 / ORIGINAL POSTEROriginal post

Thanks K996, I'm going to test this again...it's hard to believe mine can be off by as much as I'm thinking it is.

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