I use the Torque app on my phone, and an elm327 OBD2 to Blue tooth controller on my Audi and it will log every OEM sensor (even injector pulse and ICP). My 97 12v only reads RPM and a few other very basic things, but it seems to work better on newer vehicles.
Takes 3-4 readings per second, and the whole setup costs like $25.
It also reads and clears codes, displays real time data, uploads your logs for you, and will map your route on google maps with the logs based on time and location. It's pretty nifty.