Brand of Coolant

That's interesting tyarosevich,

A high efficiency coolant would be interesting in my part of the world too. I have sat in traffic when it's 46ºC (115ºF) and I was more worried about my bike than myself. Out of curiosity I had a look at the SDS to see if there was anything interesting or different.

Looking at their SDS it's a pretty standard mix of propylene glycol (PG) with some inhibitors. There are some advantages and disadvantages to PG over Ethylene Glycol (EG), the main advantage is that its specific heat capacity is higher so it can hold more heat to transfer, this is usually offset by the poor heat transfer properties of PG as it is more viscous than EG so it doesn't circulate as well and pump head losses are higher. I know the SDS only lists the hazardous ingredients but the PG is essentially 40-60% of the formulation and it's prediluted 1:1 so there isn't really a lot of capacity left for a mystery ingredient that has better performance. Particularly if you tried a different brand of PG based coolant with no change. That's what I would expect.

They also claim it to be non-toxic, it's not. PG is certainly less toxic than EG but that doesn't make the product non-toxic, particularly when it contains borate buffer and corrosion inhibitors too. I won't be drinking it any time soon, put it that way. They also say that it's biodegradable, but it's actually less biodegradable than EG. So they are pretty big on the marketing but I didn't see any performance test data on their web site that might make me more likely to accept their claims at face value. Essentially they say, our sponsored race team uses it so it must be good. Am I too cynical ?

It's quite possible that their claims are true and they have some secret IP that improves the performance, but it's equally possible that they don't.

I also wouldn't expect propylene glycol to be significantly less slippery than ethylene glycol so curious about how they get that approved for racing use.
I can't help wondering whether your engine temperatures may have dropped due to cleaning out the system and getting rid of some gunk and garbage from the radiator when you swapped over.

Did you do a coolant system flush at the same time ? I'm not doubting your observation, just curious as to whether you have accounted for all the possible factors.

 

Something else I noticed last time I bought coolant for the other half's car was that the majority of the premix car coolant was only 33% antifreeze and 66% distilled water

Only a couple of them were actually 50/50 mix maybe that is for our hot climate maybe not

Does more water content = more anti-boil properties and less freeze protection ?

I know 100% concentrate coolant does not cool very well after chasing an overheating problem for a mate , he put full concentrate in and the bike would always overheat even when moving on a hot day

When we changed it again with 50/50 mix the overheating problem vanished as fast as it appeared

 

G'day G.O.M.,

For glycol products the concentration is really more about freezing point suppression and a 33% ethylene glycol based product would protect the cooling system down to about -15ºC which should be plenty up your way. 50% product would protect down into the -20s which is more suited to US and Canadian conditions. The water is still essentially the coolant, it has a higher heat capacity and a lower viscosity than the glycols but it's also more volatile. So the glycol does improve antiboiling properties by virtue of it's reduced volatility. The pressurization of modern cooling systems has a pretty big impact too, so the formulation will mainly be about getting the freezing protection right and then the boiling point elevation is secondary. If you go to really high concentrations of glycols the boiling point will increase further as you essentially get rid of the volatile water, but then you have thick syrupy snot to circulate which automotive radiators really aren't designed to handle and you would have to increase the size of the system as the heat capacity and heat transfer properties of pure glycols are nowhere near as good as diluted mixtures.

 

"Did you do a coolant system flush at the same time ? I'm not doubting your observation, just curious as to whether you have accounted for all the possible factors."

Yes, I did do a coolant flush at that time, but the coolant wasn't that old anyway. The temperature drop could have been the result of an issue that the flush resolved, but a year later when I replaced engine ice with the cheaper Prestone propylene glycol, the engine began running noticably warmer, about as warm as it did when new. I'm due for a coolant replacement this spring, so I'll go back to engine ice and see what happens (I'm back in the Pacific NW though and it frankly never gets truly hot here).

 

I agree that the main effect of glycol addition is depression of the freezing point, so a higher glycol content does make sense for our North American cousins. Probably makes no difference at all for most of us in Oz/NZ. The higher glycol does increase the boiling point but not really by very much, 30% boils at 104C, 50% at 107C. The lower the glycol, the higher the specific heat of the liquid so the more effective it will be as a coolant. So the correct glycol level should really be the lowest that you can use and still get the required freeze protection.

Given the radiator cap is rated to 108 kPa (16psi) that will have a much bigger impact on antiboiling properties than the glycol. Water alone at that pressure would boil at about 120C, and with glycol added that would presumably push up to 125C or more. Interestingly 120C is the maximum temperature that Honda regards as "safe". Beyond that they recommend shutting the bike down and letting it cool.

 

Thanks Cadbury,

Interesting yes, at normal dilutions the glycol only increases the boiling point by a few degrees, you essentially have to go to 75% solutions for more than that, at which point it's not particularly useful in a standard system due to the viscosity increasing and heat capacity dropping off. If there were a coolant on the market that would give me better heat transfer I would use it as I've seen 120 degrees on the gauge in traffic on a hot day, dropping it down that extra 5 degrees would be worth it to me for peace of mind, but the corrosion package has to be right too. The inhibitors are a tiny fraction of the overall formulation by mass, but in our climate they're probably more important than the glycol. Didn't have so much as a frost at my place this winter but I have the coolant temperature gauge up on the display when I'm commuting in hot weather and watch it like a hawk.

 

Crikey, 120C is getting TOO hot FB. Are you sure your fan is running properly?

 

Yikes 120°C that is scary
I have never seen higher than 107° C on the gauge even when stuck in traffic on 40°C day

 

Too right mate, I have been watching it like a hawk, ever since. It will be getting checked at the first service, it was 44 degrees outside according to weatherzone so quite warm but still.

 

Couldn't agree more Cadbury, the fan does appear to be running normally and the coolant levels look OK. It was a hot day, but still, getting it checked at the first service.

 

use about 4 liters of : Pro Honda Hp coolant

Honda 08C50-C321S01 Coolant, Hp Type 2; New # 08C50-C321S02

“Prestone” regular staff or “Wurth” killed the water pump seal after about 30k KM

 

Went to pick up some Honda coolant at the local Honda dealer today. They only had one liter in stock. The parts guy filled me in on something. Honda motorcycle coolant is the exact same stuff they sell at the Honda Car dealerships probably for far less.

 

Motul Motocool Factory Line Coolant.

https://www.motul.com/us/en-US/prod...l-factory-line?f[application]=147&f[range]=21

 

Just get the Honda BLUE type 2! its premixed and under 20 a gallon! Your Honda motor was made for it:witless: