Originally Posted by donniedu
For less than 50 dollars a OBD dongle and the smartphone app Torque. The dongle sends a WiFi signal to your smart phone that via Torque displays everything the chassis might allows you to see. As a benefit you can also read and clear codes
I have one of these and it does work, but in practice a pain in the butt. You have to set it up each time you want to use it. A dedicated gauge, comes on when the engine starts, does not require any set up (after initial set up) and no battery to charge.