A history question on anti-freeze

[ericmark]

I remember there were two types of anti-freeze, one was alcohol based and it could evaporate faster than the water, so every year the hydrometer was used to check the strength, however the glycol stuff worked the other way, so if mixed the standard hydrometer did not work, there was a tester using the refractive index not sure if that worked with a mixture, but to top up one had to have a ready mixed coolant as you could not be sure what was already in the system.

Standard was 25% antifreeze, but our gritting wagons had 50%, it seems at 25% it can turn to slush although not freeze, so it stopped the core plugs popping but if engine worked hard before it had warmed up you could get hot spots.

 

[Avocet]

Very rare to see now. It's pretty much all glycol-based, and then there are two types of glycol-based stuff (OAT, and IAT) with different additive packages. I need IAT for my 30 year old Alfa, but pretty much all modern cars are on OAT. I must admit, I hadn't noticed any lack of availability of concentrated antifreeze? Halfords tend to sell ready-mixed, but I assumed that was just greed rather than anything to do with regulation?

 

[hi1]

Because waters cheaper than antifreeze, same with screen wash and fruit drinks rather than straight juice.

 

[Mottie]

Have you tried buying distilled water?