Planet-9

Speedometer readings?

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YOUR RESEARCHSpeedometer readings?

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Test speedometer

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Suggestion
If you can borrow a portable GPS like the Garmin Street Pilot you can test your speedometer.
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Speedometer readings?

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Leading evidence: 'Test speedometer' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Test speedometer' (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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Use v1 detector can be important

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Suggestion
knowing how fast you are really going and using a V1 detector can be important for some of us with heavy foots
Original post Read captured discussion
Speedometer readings?

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Test speedometer

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Suggestion
If you can borrow a portable GPS like the Garmin Street Pilot you can test your speedometer.
Original post Read captured discussion
Speedometer readings?

Use v1 detector can be important

No successful repair reported for this finding.

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Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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Discussions that contain suggestions: 1

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

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Suggestion
knowing how fast you are really going and using a V1 detector can be important for some of us with heavy foots
Original post Read captured discussion
Speedometer readings?

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

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POST 1Original post

My '99 Boxster (and all others as far as I know) speedometer read 4 mph faster than actual at any speed... anyone know the accuracy of the CaymanS ? I haven't found a radar-display trailer to test it yet.

POST 2Original post

I have heard from a few sources that Germany has some law requiring that speedometers not read low and hence, most of them read high. If you can borrow a portable GPS like the Garmin Street Pilot you can test your speedometer. The Garmin is accurate to .05 meters/second which should work out to a fraction of a mph. Alan

POST 3Original post

Also, the excessive speed reading is a percentage, not a perset mph. For example in Bimmers is right around 7%, I do not know what Porsche's is.

POST 4Original post

wasn't a percentage in my '99 Boxster... precisely 4 mph too fast at ANY speed... and this is what other owners were reporting also... I'm checking with GPS unit later this morning so I will post results this evening... knowing how fast you are really going and using a V1 detector can be important for some of us with heavy foots

POST 5Original post

Comparing GPS to speedometer: speedometer read about 1.5 mph faster at all speeds 30-70

POST 6Original post

That's pretty good. What size wheel do you have? According to my calculations, the 18' wheels have a smaller circumference. Thanks for taking the time to speedo check.

POST 7Original post

I have the 18' Cayman wheels with Michelin tires

POST 8Original post

Somewhat related to Speedometer readings. I got in the car after the wife had a drive and looked at the Speedometer and surprised to see that it said Robert. When I got my bearings I realized that while driving the Cayman she had dialed in a classical radio station which was now playing Robert Schuman's something or other. The FM station was sending out the composer's nameand the name of the piece that we were hearing. I have seen this before on my other cars within the radio readout, but was surprised to see this showing up under the digital speed number in the center of the instrument cluster. Then for the first time,I suppose, I started paying close attention to all of the information displayed on the three instrument dials. The computer spreads it's info across all three dials.This makes for a lot of useful and interesting info. If you happen to not be highly engaged in the driving experience, something that is difficult to do, you will be entertained by all of the good information your computer is displaying on your instrument panel.

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