Using this oil temperature adaptor is the easiest way to fit an oil temperature gauge into an Impreza. Highest quality precision machined brass adaptor replaces the bung located over number 3 cylinder. This is regarded as the best place to locate the sender as cylinder number 3 runs the hottest and it is often the one that causes engine failure. Direct fit and will allow the fitment of any gauge that uses a 1/8NPT sender.