I just got a new 2016 Legacy.  In checking the fluids I noticed that the Coolant level was just above the low mark.  The engine was cold, outside temp about 32 degrees.  The manual says it should be at the full line when "cool".  I asked the service advisor at the dealer and he said the manual was wrong.  He said when the car is hot, the level will expand to the full line.  Seems logical to me. So, what do you think.  Thanks.

There should be a max and min line, or full and min line.  The coolant must be between these lines at 68 degrees F. It can be all the way to the full line at 68F but if you fill to the full line at 32F, when the engine comes up to operating temp, the excess fluid will spill out the top of the overflow reservoir.  It wont hurt anything other than spilling a toxic chemical into the environment where someones pet (or child) might lap it up and die, but it wont hurt the vehicle any.

I have a 2016 Outback. Many 2015/16 Subarus come from the factory with low level of coolant in the overflow reservoir. Many say that's because they didn't fully burp the cooling system at the factory so the level gradually drops as you drive the car (it burps as you drive to let out trapped air in the system). Mine was in the middle of the hi/low marks with cold engine when I took delivery. It gradually dropped about 2 inches in the first 2 months and then stayed there. I read about many such reports on another forum. I think your service advisor was wrong. Whatever is stated in the manual is correct. But in any case, as long as you have at least some coolant in the overflow, the radiator is full or near full and that'll do its job. I keep it at full mark with a cold engine for both my 1996 and 2016. For both cars, it does not spill out of the overflow no matter how long I drive the cars.

Edited January 25, 201610 yr by vasy

The lower line on the expansion tank is the full when cold line.  The upper line is the full when "hot" line.  At 32F the coolant should be there at that lower line, a little above or below is ok.  When the thermostat is opened and the motor is "hot" the coolant should be at the upper line, again a little above or below is fine.

Edited April 13, 20169 yr by screwbaru2