Good point. I have one installed between the oil filter mount and spin-on filter. I had to reconfigure the hoses slightly when I installed the Mocal fluid switch but it wasn't that big a deal - a couple of new hoses and re-route some that I had and done. Watching the (fantastically detailed and accurate) oil temp gauge, everything seems to be working as planned - It usually runs 180º-ish in the Winter and 200º-ish in the Summer.