Just curious...'cos I notice my coolant expands and rises by just about anything from 0.5mm to 1cm above the F mark. It's back at the F mark when cold.

Do quite a lot of highway driving and don't really get into traffic snarls.

What about you?

 

That sounds about normal (and completely ****) to me.

 

Yeah I guess I'm really being ****...but then I used to see that green stuff rise much higher previously, than now..

 

I think everything expands when its heated.

 

That is about normal. A little more expansion might even be OK.

 

You can actually measure a HALF A MILLIMETER variation in your coolant, in the reservoir ?

 

I think he meant .5cm, not mm.

 

I'd say it's more than that on my car using the Evans NPG-R coolant, at least 1/2"

most people overfill the surge tank too