The Scan Gauge II is a neat device that displays engine information, serves as a trip computer and has scan-tool capabilities.
Unlike a typical handheld device, this small gadget ($170) plugs into a vehicle's Data Link Connector (found on 1996 and newer vehicles and generally located underneath the driver's side dashboard) and is attached to the instrument panel for daily use.
The engine readings include temperature, throttle position, fuel-system mixture corrections and more. The trip computer capabilities include instantaneous and average fuel economy, fuel used, miles to empty, drive time and maximum speed. The device's scan-tool capability can read Diagnostic Trouble Codes, check emissions test readiness and more.
The fuel economy indication should be taken with a grain of salt, as the projection is based on accurate but incomplete information. But the changes in fuel economy you might see by fine-tuning driving habits would be accurate. Thumbs up for this device for mileage maniacs, techies and vehicle enthusiasts.
Bergholdt is an automotive technology instructor.