Performance meters are devices that can measure the actual performance of your car. However, one should be very wary of manufacturer claims about accuracy. To get the best from these meters, you will need to calibrate them on your individual car at a ¼-mile dragstrip beforehand. Once properly calibrated, some of these meters can then provide excellent accuracy for just a few hundred dollars. Car and Driver tested a number of these devices (ranging in price from $90 to $11,800) in their May 2005 issue. Click here to read the article...
These units measure acceleration against time – from which speed, position and distance are calculated. These units can be sensitive to vehicle pitch or roll and calibration is required for getting the most accurate results.
AP22 and AX22 from Race Technology
G-TECH/Pro from Tesla Electronics
Passport G-Timer from Escort
PocketDYNO from Hamilton Performance Products.
Tazzo from Gold Coast Electronics
VC3000 from Vericom Computers
These systems measure position against time – from which acceleration, speed and distance are calculated. Differential GPS technology provides the most accurate results.
G2X from Racepak Data Systems
These performance meters record telemetry as measured by the car's onboard OBD II diagnostics systems (fitted to all cars sold in the US from 1996). Their disadvantage is that they are only as good as the car's onboard systems.