u deff want ur engine to operate at lower temp bc if u achieve this u wont have a heat soaked engine. when this happens u do lose power. i had an oil cooler and lower tstat on my past car it it kept is extremely cool. therefore it would never feel slugush after it heated up. plus it will help keep ur turbo cooler..deff a plus. i just bought a 160 degree tstat for my 1.8t and ill soon be gettin an oil cooler i just have to find fitting to fit the oil lines.