Actually the 5 volt IVR the factory uses came out way before any computers were on cars. Unless you mean any computers other then on cars ? Ford also used this setup as I don't know why they decided on 5 volts other then that's the best for the type of factory gauges that use a bi-metal strip that bends to move the needle. The voltage on them gauges has to be steady or the voltage changes just from the charging system with the car running would make the gauges move around. Now GM used magnetic type gauges that uses 12 volts to them and they use to wound coils to move the gauge as one coil is grounded and the other goes to the sending unit so it varies how strong it is to pull on the needle and move the gauge. I don't know which are better but you can tell when cars had the GM type magnetic gauges as they usually will stay where they are when the key is turned off and of course the Mopar and Ford type bi-metal gauges go back to zero or empty when the key is turned off. Ron