I have oil, temp, and tach in my car. Granted I usually do not look at them while under green, but I like having the information during cautions, after the race, and if I am trying to sort out an issue. I could live without the tach, but like having the other information so that I know if I am having a serious problem. Oil temp also lets me know if the car is warmed up before I pull on the track. Then again, with all of this I still threw a rod after 5 races on a motor.