Recently Installed the Apexi Turbo Timer in the car. Since Im cheap and only have an oil cooled turbo, it is needed even with the oil cooler. Description: The Auto Timer stands as a technological marvel. The pen shaped, compact size makes the Auto Timer one of the smallest turbo timers on the market. This allows a clean and stylish installation virtually anywhere inside the car. The unique multi angle joystick button allows easy navigation through the many feature menus. Upgraded in everyway from the previous model, the new Auto Timer can automatically determine the necessary amount of after idling time. A Manual Mode allows the user to preset desired idling times from 0 sec.~10 minutes in 16 increments. By inputting O2 sensor voltage, the Timer can also display theoretical air fuel ratio. Since the Auto Timer uses the factory O2sensor which is primarily designed for emissions, the readings may not be as accurate when the O2 sensor is cold. A'PEX recommends that the O2 sensor readings be compared to a high grade "tuning" O2 sensor for comparison. The Timer can also display critical data such as O2 sensor voltage and Battery Voltage. To prevent potential theft while running, the handbrake safety feature shuts off the vehicle when the handbrake is released without the ignition key. Not much to it, except its very small, and easy to install. Basically a turbo timer, the best feature is A/F inaccurate as it may be. Features of note: A/F Ratio:Not most accurate, but good enough to know if there is a problem. Voltmeter:Useful to some, esp with stereos. Auto Time Feature:Works well, I usually do not use. 02 Voltage:Same as A/F Ratio, guess could be used to tell if sensor is happy. Install:Very Simple, HKS harness is available for spliceless connection. Splices that are optional: 02 signal from ECU (See Pinout) Handbrake Wire to prevent Theft Price:$75-$150 Overall: (Of 5) Nice to have voltmeter and A/F available. Others have boost, but I prefer analog for that.