All this talk of antifreeze and knowing some +8’s are a bit marginal on cooling I thought I’d dig out my old notes from trying to cool tuned Minis I’ve tweaked
The best coolant is actually pure water, distilled to remove hardness & bits, this will not then contribute to corrosion & has the best heat capacity
Antifreeze (ethylene glycol) heat capacity is only 2.42 jules, water 4.20 & it’s denser than water, so when you crunch the numbers it actually carries around 37% less heat per volume than water
So for simplicity if we call water 1.0, then a 25% antifreeze mix will have a heat capacity of 0.91 and a 50% mix just 0.82
As you can see the less antifreeze, the better the ability of the water to move heat from the engine to the radiator, BUT of course you need some corrosion protection & resistance to winter freezing so we use antifreeze, but it’s not good practice to use too much just to be safe
As an aside to this the various ‘waterless’ coolants blend of magic additives is mainly…taadaa!.. ethylene glycol.., you pay’s your money & take your choice, but remember it WILL reduce vital heat transfer
