My car usually sits on 176 all day long. However, I gave it some beans the other day (empty winter autobahn) in 22 up to 170mph. The engine temp dropped to 115. :-0. I backed off. I guess the sucking of cold air does it but is it safe to drive like this as the dial is actually showing cold engine?

 

Dont know if helps or where the temperature sensor is located exactly, but I drove my car in temps like those and speeding the same, but engine temp was the same as usual.

 

That's weird? Did you go 170 and above mph? Because up to 120-140 mph my temp was normal too, then all hell broke loose!

 

How long was the car 'up to temp' before you got on it?

 

I would suspect the thermostat... I don't have much experience with 170+ for any extended periods, but as I understand the theory, the added efficiency of the cooling system with the extra flow you would experience at 170 should cause the thermostat to close to maintain the optimum engine temp.

 

+1. My thoughts exactly.

 

Properly warmed up. 20 minutes @ 70mph cruising.

 

Interesting and plausible answer. But what is the actual temp? And is it safe to drive 180mph in cold weather if the gauge is showing below norm operating temp? What is the actual temp of the engine?

 

i don't know if its a euro thing but mine runs at 180* F when warmed up. confirmed by my proefi can logger

 

I don't think we are on the same page. Mine runs at 176 F all day long in normal conditions. Even when I was at the ring my engine temp was rock solid. Same goes for when I am driving on the autobahn in the summer. The question relates to winter driving at 22 F when at 170 mph I have experienced a very sharp drop in engine temp on the gauge down to 115 F at above mentioned speed.

 

sorry got the 170 mph and temp * mixed up

 

Could the pressure from the water pump at that RPM be overwhelming the spring in the thermostat? It shouldn't be dropping temp IMO.

 

Sounds like it could be the thermostat stuck in a partial closure - the radiators temp will drop due to speed and the temp would drop within the engine block quickly - the water pump is spinning at 5k rpm so the coolant freely circulates and is dependent on speed. Plausible?

 

Plausible. But regardless of the thermostat state, what is happening with the actual engine temp? Is the gauge correct? If so, surely driving flat out at 115 F engine temp isn't good? Ps. When I backed off temp went back to normal within 15 seconds.

 

Yes been around 170mph a few times, but after reading your last post something is weird, temperature has a high inertia, not very easy to go up or down in 15 seconds like that..