Is it critical to change coolant at 100K?

[tmontague]

As i stated above, this will be fine but you will dilute your new coolant below 50/50 due to the water left in it. Make sure you test your coolant's freezing point once you swap it out

[RMcG]

Originally Posted by tmontague

As i stated above, this will be fine but you will dilute your new coolant below 50/50 due to the water left in it. Make sure you test your coolant's freezing point once you swap it out

Thanks tmontague. I did indeed read your previous post about how you run different dilutions and I am aware that the freezing and boiling points change with dilution. I was more worried, however, about the effect of dilution on the corrosion inhibitors and the lubricants.

I just bought two gallons at the local Toyota dealer, total cost with tax $50 USD. But my worries about corrosion inhibitors and lubricants may be moot, because according to the information on the coolant bottles, the 50/50 freezing point is only -34 degrees Fahrenheit. That is OK where I live now in the Pacific NW of the US, but if I go back to Montana, it is not OK. Because it can get to 40 below in Montana. I will have to call a Toyota dealership back in Montana and ask them what they sell for coolant.

Thanks,

R.

[RMcG]

Originally Posted by RMcG

... my worries about corrosion inhibitors and lubricants may be moot, because according to the information on the coolant bottles, the 50/50 freezing point is only -34 degrees Fahrenheit. That is OK where I live now in the Pacific NW of the US, but if I go back to Montana, it is not OK. Because it can get to 40 below in Montana. I will have to call a Toyota dealership back in Montana and ask them what they sell for coolant..

A busy airport in Montana recorded a temperature of 39 below zero in March of 2019, so this is not an academic consideration. I called a Toyota Dealer in Fairbanks, Alaska, and they use Toyota brand coolant 00272-LLAC01, which is undiluted. (I think this part number is off by one digit, see below.) It costs $30USD. They dilute this 60/40 with distilled water to get a freezing point of 62 below zero.

I think the actual number is Toyota 00272-1LLAC-01, see this amazon link.

I am not sure if this other part number coolant can be delivered to a local Toyota dealer here or not. But I will call tomorrow and find out.

Thanks,

R.