coolant type

Hi- just checking the coolant on the van for the first time. It's blue..I think the red OAT stuff is recommended?..can I leave it in there for now?

I've used blue coolant in the past and its been fine. Last time I used Prestone - it can be added to any anti freeze as a top up and I can highly recommend it. I've had it in my van for 11 months.

recommended....ethylene-glycol-based and change every 2 years!

It was good enough for Spitfire V12 engines. That's all they used - no water - just neat Glycol.

Neat Glycol does not carry heat as well as water.

Don't know on that Matt but I read that is what they used.
If you think about it the planes would be left out in freezing temperatures on the Airfields in the winter and water would freeze up. Also presumably Glycol has a higher boiling point than water.

It has a boiling point of 188 degrees Centigrade. Viscosity is obviously thicker so doesn't dissipate heat as quickly as water but more than made up by the Higher boiling point.

Well, according to the Haynes Workshop Manual for the Wellington bomber, which used the same Merlin engine as the Spitfire, the mixture was 70% water and 30% Ethylene Glycol to standard DTD344A.

I couldn't check the Spitfire manual as Smiths didn't have it.

Only thing is, I can't compare this to the Hijet since the Owner's manual just says use according to the manufacturer's instructions for the local area and the Workshop manual doesn't say anything.

Glycol does have a higher boiling point, but that is not the issue.

We measure a fluids capability of carrying heat by its "Specific Heat Capacity"

Glycol is something like half the SHC of water, so per gallon it can only carry half that of water

This is why we use a 50/50 mix in cars, as we get to keep most of the SHC, while increasing the boiling point to about 125 degrees @ 1 bar (due to the pressurized coolant system under the rad cap) while resisting freezing down to about minus 15.

My local Parkers computer recommended G30. Which is orange by the way.