So I have the 180 degree inline mod and during cold months coolant temp is usually in the low 170s to low 180s, is it bad to run the engine at such a low temp in the winter time or would running a higher thermostat just give better heater function?

 

no that is fine

 

Might be a reason thinner engine oils are specified during winter.

 

Should be fine, if you are in extreme cold you can run a higher thermostat if you want hotter air out of the heater. Will not hurt the engine or fuel economy.

 

Does running at a lower temp (170) have any effects at all? Curious as I run a 170F thermostat (40-60F weather here).

 

I am having the opposite problem, it’s gotten colder and mine is running 5 to 10 defrees warmer than usual.

 

I use a 195F thermostat year round with the side effect of better heating in the cabin. 195F doesn't make trouble in summer either.

 

Like Discorama, in the P38 I’ve been running a 190 (or 195) t-stat and I would recommend it.

 

I must be a strange anomaly (well I’m strange no matter what but that’s a different discussion) in that even in super duper extreme scenarios with thick oil (I don’t use summer and winter oils), the typical 180 T stat in the OEM configuration, my junk behaves just like it does in the summer with the exact same temps in the engine. As always, because I like pics and proof of the pretty significant weather we get in the winter at times at the house in the States:



After running for a few minutes on a different day:



Ever since doing the EGR or PCV or whatever it is “modification” I don’t have any appreciable leaks from the engine, it runs as smooth as I’m sure when it left the factory and I’m at 184k on the clock…

 

In Chicago we have had temps with wind chills below 0 the last few days. I put the 195 in for these conditions. The 195 keeps the cabin nice and toasty. The wind chill makes it all to crazy to keep the Disco warm and toasty in the mornings with a 180. We have had 30-50mph winds over the last few days. When these conditions hit I slide a piece of cardboard in front of 1/2 the radiator. Extreme cold: -5 to -40 with wild chills I'll block most of the radiator. As mentioned, a winter weight oil (5W40) and an Oil pan warmer. These are not the temps to be stuck with 15w40 in the Disco. After the artic months I'll change oil to 15w40 and put the 180 back in. Majority of the semi-trucks I've seen this week have the front noses all closed up.