Thread: Coolant mix gives more power

Originally Posted by Solomon

Debate this as you wish, but I'm amazed at the performance and power improvement.....

I live at a location where I regularly travel up a steep hill rising 700m in about 10km. It's the hill that tells me how the engine's going.

For years the engine temperature has risen as I travel up this hill - totally predictibly.

I've cleaned the radiator, replaced the viscous fan hub, changed the position of the spot lights. Can't fix it.

Basically, I've accepted that I need to travel up this hill with care. Can't beat it - then live with it.

As the temperature rises, I have also noticed the power back off. Sluggishness is probably the best description.

Pushing the vehicle hard in other areas on hot days at highway speeds has also resulted in temperature increases.

I've just accepted this as a Defender quirk. I've had the vehicle for over 10 years!

Recently, I decided to change the coolant. I messed up the process and resulted in much more water than coolant. I ran out of time to "fix" the problem immediately. Estimate about 70% water to 30% antifreeze/coolant. It was 50:50.

This mistake - what a difference in performance! I can now push the 1995 Defender (300tdi) flat chat up the hill. Temp remains steady and power is noticeably improved - even passengers have commented on the performance up this hill.

Yes, I know there's recommendations for mixture ratios - coolant effect, antfreeze, anti-corrosion etc. However, this is an incredible power improvement for little effort.

Clearly the new mixture results in greater heat expulsion from the engine allowing it to operate cooler and more efficiently.

I will check the ratio using a meter from a local mechanic soon to ensure I have the required freezing and corrosion protection.

Who'd have thought I could power boost my Landy with some extra water!

Its a known fact that water has the highest specific heat of any common liquid. Glycol is much lower so you are on to something.

glycol is nowhere near as good as plain water when it comes to conducting heat.

if you need the 50% gycol so you dont get frozen water in the radiator you can use water wetter to get the heat conduction back to about what water on it's own will do.

otherwise forget the glycol and just use an inhibitor..

any going anywhere near the power increase bit other than to say it might be time to give the intercooler a good clean out...

We don't need anti freeze in most parts of Oz,I got a noticeable increase in performance when I took the A/C condensor out. Pat

Originally Posted by PAT303

We don't need anti freeze in most parts of Oz,I got a noticeable increase in performance when I took the A/C condensor out. Pat

Yep, my temps rose around 3-5* on average on hills with the AC condenser re-installed in winter one year. (VDO mechanical gauge)


FWIW OAT and HOAT coolants also have better heat transfer coefficients compared to regular inhibited glycols. One paper I read claimed roughly half way between straight water and a conventional glycol coolant.

yes Pat, I know what you think of OAT inhibited coolants

Originally Posted by rick130

Yep, my temps rose around 3-5* on average on hills with the AC condenser re-installed in winter one year. (VDO mechanical gauge)


FWIW OAT and HOAT coolants also have better heat transfer coefficients compared to regular inhibited glycols. One paper I read claimed roughly half way between straight water and a conventional glycol coolant.

yes Pat, I know what you think of OAT inhibited coolants

Good one Rick,you made me laugh.I think destilled water and water wetter would be a good hot temp mix. Pat

This is very true. There used to be a product called Water Wetter that was way better than modern coolants. The best I've found on the current market is Penrite SIN Racing coolant. We use it in all our old Brittish cars, very cool

Cheers,

Originally Posted by PAT303

Good one Rick,you made me laugh.I think destilled water and water wetter would be a good hot temp mix. Pat

Tim Slako (the Redline Importer) told me once that that is what they did to get around the overheating problem with GQ/Y61 TD42T Patrols, but I've never been game to try it, using OAT instead (and the thing still got hot.....)

As with many things in car design, coolant is a compromise - of course, its main purpose is to cool the engine, and as this thread has pointed out, there is nothing better than water! But it is also necessary to stop the stuff freezing - and fortunately, in most parts of Australia, this is not a concern, at least for most of the year.

But since the common use of non-ferrous metals in the cooling system (i.e. for Landrovers since the V-8 came in), corrosion properties have become much more important, and are probably the most critical factor today. This is compounded by the fact that, like almost all cars today, they are designed by engineers who live in a cold climate, and do not really have sufficient spare cooling capacity to cope with prolonged full throttle operation at low speeds in 40+ temperatures, as you can get just about anywhere in Australia if towing or operating on steep hills. Add a bit of sludge and a few insects in the radiator fins (why is a chaff guard not standard?) and even if the temperature does not reach the red, it can easily climb above normal. And particularly with turbodiesels, this invariably means the incoming charge temperature is above normal, reducing performance noticeably, at a time when you are using all you have.

There is no simple solution - using more water in the mix helps the performance, but risks serious engine corrosion, although I am not sure to what extent.

John