Oil temp gauge install

[hcj986s]

Previous to my Boxster S I had a 944 Turbo. I added the VDO oil temperature gauge, and plumbed the sensor into the oil return line coming off the turbo into the sump. On track, temps would get to 150C / 250F consistently.

Prior to the 944 I had an E36 M3 which I also put in an oil temperature gauge. On track, never above 110C / 230F.

I suspect Porsche tested the oil temperature behavior of the Boxster heavily and found that an oil temperature gauge was redundant. Likewise, BMW probably found the same with the US-spec M3 engine (the Euro spec E36 and all subsequent M3's, which have Euro engines as well, have oil temperature gauges). Frankly, I don't get why these gauges aren't included anyway on Porsches, but I suppose one has to cut costs any way they can. Hence the Boxster's 4-gauge instrument cluster rather than the 996's 6-gauge IC.

Another use of an oil temp gauge is to determine whether the car is warm enough to push hard. Water temperature comes up quickly, but oil temperature lags. One trick is to monitor oil pressure; until warm, the pressure will stay at max even at idle. Once warm, it will begin to fall at idle.

Me, I'd put in a VDO gauge in the center console (oil and volt) if I were really concerned, but I bet it's a waste of $100.