Coolant question for extreme temp

Right. And this was for a 1983 Land Cruiser which already had a tendency to overheat even when it was working at 100%.

 

OP lot of good information here but why don’t you ask your questions on the Alaska forum. Get your answers from Alaskans who should know well of all you ask.

 

my original question was is it ok to mix Toyota red coolant with pink coolant. Seems specific enough for a Toyota forum and not my Alaska forums…

 

I’m talking about the Alaska forum here on TW not what ever other Alaska forums you are involved with. Pretty sure the TW Alaska guys would have all the answers to your questions. It was just a helpful suggestion. Post where ever you want.

 

I have done it on accident. They are considered to be compatible.

 

Just went and bought a cheap tester, because I was interested to see. It seems as tho the pink coolant is good to roughly -50. No clue to accuracy of these tests, but it is most certainly maxed out.

 

You can "calibrate" those cheap testers with a 50/50 mix. Put 2 ounces of coolant and 2 ounces of water in a disposable cup. Or whatever. Just make it half and half. Mix it up. Test. You should get ~-35F. My ancient Prestone tester was off, so I marked the gauge with a sharpie. If you want 60/40, whatever your goal, then do that and mark accordingly.

In Alaska it won't matter, but coolant has a lower specific heat, transfers heat less effectively, than water. If it didn't, we'd all just use 100% coolant and zero water.

 

It’s not just about the cooling ability, 100% coolant freezes much lower, ethylene glycol at about 10°F

 

there are charts that say what dilution to run based on temperature.

 

Yes, i was just curious to what a tester actually said, @Bishop84 had said earlier that premix was good to -50 via testers, which that seems to back up, but you are saying that the testers are not calibrated equally and some will show higher numbers even though 50/50 is rated for -34?

Either way i am going to be changing the concentration to 65/35 to make sure i have no issues with the cold during the stay. Id prefer to just drain 2.5 qts of pink and add 2.5 qts of red to achieve that without having to flush the whole system as the coolant in it is only a few months old, but answers around doing that seem to be mixed.

 

The topic of coolant compatibility keeps coming up, and there is a LOT of misinformation about it.

Here are FACTS about the coolants used by Toyota:
Up to 2005: Toyota Long Life Antifreeze Coolant p/n 00272-1LLAC(-01) in RED sold as concentrate** for 2 years -or- 30,000 miles (whichever first) and must be mixed with distilled water

2005 on: Toyota Super Long Life Coolant p/n 00272-SLLC2 in PINK sold as pre-mixed 50/50 for 5 years -or- 150,000 miles (whichever first)

Toyota issued a TSB on the color change from red to pink coolant in 2002;

 

In Canada the pre-mix is 55/45 for the colder weather. American stuff (maybe except Alaska) is 50/50. I don't have a jug on hand for the exact number but Bishop is probably right.

At the least I can say that down to -43*C my truck does start without being plugged in

 

I know Alaska winters can be on a whole other level, but I will throw in that I lived in northern MN for 8 years and it would routinely hit -30 and occasionally -50 in the winter. My truck sat outside 24/7 (no garage). I never used anything other than pre-mixed OEM coolant. I also did not use a block heater. Only issues I ever had were with the battery. I kept a jump pack in my apartment so I could start my truck if the battery was too cold. Otherwise, she never let me down. I'm still rolling at 257k.