POST 1 / ORIGINAL POSTEROriginal post
how accurate is the digital speedo on a 996 ? when it reads 70mph what do you think is true speed ?
6 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
Discussion summary
YOUR RESEARCHspeedo accuracy
1 matching discussions were examined; no attributable action/outcome evidence was detected. No consensus or repair conclusion is claimed.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Read captured repliesInsufficient extracted evidence does not mean there is no answer in the original discussions.
1 matching discussions · 6 captured posts examined · 0 partial discussions
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.
6 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
- Porsche Club GB: 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: 20261027T144324Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
POST 2Original post
I've checked this against an on-board GPS system and my speedo over-read consistently by 5%. Edited to add: By 'consitently' I meant from low speeds to high speeds the over-read was consistently 5%
POST 3Original post
Both of mine measured 66 mph on RoadAngel at an indicated 70
POST 4Original post
A point to note is that if you have non-standard alloys,deflated/over-inflated tyres,and/or any other factors which will affect the rolling radius, these will all lead to deviations from the manufacturer's basis for the speedo calculation, and therefore the speedo reading, ergo misreadings are dynamic. Therefore you can't really compare one car's misreadings with another's unless you control for those factors.
POST 5Original post
Like Nick's, my speedo reads 70mph at 66mph GPS. My C2 did exactly the same.
POST 6Original post
Yep - mines the same. To be honest I prefer it this way - at least I now attempt to keep to the low end speed limits where most of the tax cameras are hidden.
This is a source reference. Confirm exact model applicability in the original material.