[Miata] speedo/tach accuracy

[Neil Tusing]

>From: "Anthony Oliphant" >
>I have a '94 5 spd, m edition. They speedo seems to
>be running a little fast. What are the revs in top
>gear at 60mph, or 80mph??
>
I thought it was a common rule of thumb that in top
gear (5th or 6th), MPH was equal to 2 percent of RPM,
ie multiply RPM by 2 and divide by 100 (or multiply by
2 and drop 2 zeros).

That was the case in my '93 5-speed, although I never
checked it with a GPS.  It is definitely the case in
both my '01 LS, 6-speed, and my '04 MSM, 6-speed.  And
I have checked both with the ScanGauge II and GPS.

>From about 60 MPH on up, the car speedo reads about 5
MPH high.  Here's a post I did in March, right after I
got the ScanGauge, comparing MPH and RPM between the
car and the ScanGauge.

http://list.miata.net/pipermail/miata/2007-March/079518.html

Neil Tusing
Dual Citizenship:  Del-Val/LVMOC