"Normal" (gauge in the middle) would be about 210 degrees. The thermostat doesn't fully open until that temperature. With Forscan with the A/C off I noticed that the computer doesn't turn on the cooling fans until 220 degrees. Fans run until temp goes down to 205 then they turn off and the grill shutters partially close, and this is on a hot summer day. Modern vehicles like to run what some would consider hot.

And if you live in the south like me, the fans do run all the time because the A/C is always on. On a hot day after the truck has been sitting in the sun the fans will go to high speed shortly after start up for A/C performance.

 

This is what I use to monitor things like engine temp. Some will not find it desirable to have something hanging off the windshield but, it's still an option. This particular one is a SC Dashpaq which is also a tuner. There is an entire list of engine monitoring stats that can be set up as well as other useful stats and tests. This being the main screen, the secondary screen (arrow right) will show up to six monitoring stats. In other words, you can monitor virtually every engine stat you desire generated from a PID list. I find this 'tuner' very useful in monitoring engine functions.

That said, there are many other good 'tuners' out their that can do the same kind of thing. I like this one.

 

it varies - it doesn't vary much (maybe 15% max) and for most of the country it won't matter. Biggest detriment is time in stop and go traffic - but hey the engine shuts off at stops right? for some people.

What's often lost on most people is that some 30-40% of the cooling capacity of the engine is actually in the oil not the coolant. which is why you have a oil cooler too. At operating temp - and with load - while moving some 20-30 MPH it should hover around the standard 210F. with excursions to 240 if you were to sit still and the fan not come on quickly. Which is also why the engine would shut down if the temp got way out of that range. Been a while but if I recall correctly that limit is 300F.

The fan on your device is meant to move air about equal to a 30 mph speed. once you are going over 30 - you are getting extra capacity. Another factor here is the engine RPM - which is to the effect of the water pump RPM and the CFM of water movement. another issue with sitting still and a parameter for the start stop system. I say all that to say this - modern synthetics and the design of the lubrication system doesn't so much care about the OAT but it is a factor considered. The engine itself only gets so hot - period. And that factor is more rpm and load demand not OAT - and incidentally high OAT's lessen performance. But it does reduce cooling capacity - that is in the design of the oil cooler and radiator size, fin depth, pipes etc etc. HAS nearly no bearing on the oil today.

ALso OLM algorithm does indeed factor in OAT as part of it's detriment counter - but it's not nearly as high a detriment as people think it would be.