direction. I'd either calidrate it with a guage you can temporarily plumb into the cooling system or get yourself a "baby Techtom". They are under $200 and give you an accurate cooant temp reading (and some other features that I don't recall). I have one that I haven't installed (as my car has been down) that I bought because of the lack of accuracy of the stock gauge. I'd tell you what part # it is but I seemed to have misplaced mine. It's about 2" by 1" and I think I paid around $180. You can probably get one from a number of forum sponsors. Take care, Mark