Thread: COOLANT-WATER RATIO?

Ethylene Glycol has a lower specific heat than water, so a 50/50 mixture has more trouble carrying away the heat. This mixture is for winter only, I wouldn't run it in warmer weather. Despite your mixture raising the boiling point of the coolant, it gets hotter faster, so you don't want it until the frost sets in.

You are of course theoretically correct.

However Land Rover obviously think that 50/50 is the correct ratio as that is what is stipulated and their cooling systems are sized accordingly.

I have NEVER had an overheat in my RRC with 50/50 and have never in fact had the temp gauge move even to half which is about 105C , even low ranging in 40C plus.
Regards Philip A

You will also find that when dropping your coolant ratio to 33% (and most coolant blenders warn to never drop below this level) that the corrosion inhibitors aren't near as effective, so it's best to maintain close to the 50% mark unless you have an all iron engine and copper radiator.

It's also a PITA to be changing coolant ratios every six months for differing seasons so I've always maintained a 50/50 ratio (or as with my current coolant it's a pre-mix at 50/50, and yes Philip, they use de-ionised water, it's made by Cummins and is a total life coolant for their big diesels)

Is that the green coolant commonly sold in autostores or a special type for the 300tdi? Having an alloy head has an effect, doesn't it?

I recently bought some green coolant at Repco. I think it was actually Repco brand.... If I remember correctly, they had at least 2 different green coolants in the same brand. Not all were suitable. At least 1 was...(I hope, or my TDI is going to hate me). Easily way at somewhere like Repco is just ask. They have all the recommendations for every model vehicle. So as long as you just want the stock standard to go with stock standard engine etc, they should be able to help.

It doesn't really matter what colour you have AS LONG AS IT IS THE SAME AS WHAT IS IN THERE" or you have well and truly flushed the system of old coolant.
Usually the green is Ethylene glycol so is toxic to humans and dogs so don't drink it. It tastes sh ..house anyway. This should be changed every 2 years or so, but NULON Longlife can be left longer.( this is what I use)

the red stuff is OAT and lasts a lot longer and the impetus for this was AFAIK European regulations designed to reduce toxic residuals, much like "lifetime " ATF, and we know how well that works.

Ther eis of course also the magic blue stuff from Honda which will last 10 years so they say. It better as I just bought 5 litres orf 50/50 premix for my new 6 year old Jazz and it cost $67.

Antifreeze - Wikipedia, the free encyclopedia

Regards Philip A

Originally Posted by PhilipA

It doesn't really matter what colour you have AS LONG AS IT IS THE SAME AS WHAT IS IN THERE" or you have well and truly flushed the system of old coolant.
Usually the green is Ethylene glycol so is toxic to humans and dogs so don't drink it. It tastes sh ..house anyway. ....

Regards Philip A

Actually it tastes sweet that is why dogs drink it... pedantic, I know.

I know, I know it was a joke.

I hope it is toxic because I'm about to flush it down a drain into my gravel pit and try to kill a root which is growing in the drain.

I understood there was a difference with alloy heads.
When my radiator core was replaced two years ago they used a green coolant but I'm not sure which one it was...

Given all psts provided here, I still find it a bit confusing that the Land Rover manual specifies the following:

Engine coolant (V8i, Tdi, Mpi): Use an ethylene glycol based anti-freeze (containing no methanol) with non-phosphate corrosion inhibitors suitable for use in aluminium engines to ensure
the protection of the cooling system against frost and corrosion in all seasons. Use one
part anti-freeze to one part water for protection down to -36°C (-33°F).
IMPORTANT: Coolant solution must not fall below proportions one part
anti-freeze to three parts water, i.e. minimum 25% anti-freeze in coolant otherwise
damage to engine is liable to occur. Or a maximum of 60%.

Now Techaloy Xtra Cool Gold contains 280g/L Ethyene Glycol and recommends that 1L will make up to 15L. Even if I ran Techaloy neat (undiluted) I would still not achieve 50% anti-freeze as suggested by the manual. What's missing here is the original Land Rover concentration (mg/L) of the factory coolant. This would clear things up nicely. Any comments welcome on 'corrosion inhibitors' mentioned in the spec. They don't seem to be present in the Techaloy product I was recommended in the auto shop.