Coolant Recommendations

[Dr_Snooz]

I watched a few videos on YouTube recently that discuss the 17,000 different types of coolant available now. Which left me confused. Green coolant is supposed to be replaced every 2 years. I hate replacing coolant. The stuff is poisonous, makes a gigantic mess and is almost impossible to dispose of here in my area. I want a 5-year formulation. I used to buy a 5-year green coolant from Kragen (before they turned into O'Reilly) and assumed that all the green coolant I've bought since is also 5-year coolant. Looking at my latest bottle, however, I see that is not the case.

TLDR:

• What is the right 5-year coolant (or 10-year, if that's possible) to use in my Suburban?
• How carefully do I need to purge my system before switching?

Thanks!

[VileZambonie]

Use what's recommended and rather than changing it in a prescribed timeline, change it when it's needed. Buy some quality test strips and check it.

[werewolfx13]

Be careful with long life coolants in our trucks. None of the modern formulations protect copper & brass radiators and heater cores from corrosion. Conventional green is the only consistently silicated coolant you’ll find, and its corrosion inhibitors break down relatively quickly. As Vile said, pick up some test strips and test regularly. If you don’t want to deal with a whole changeover, you can extract a portion of your coolant and replace it with fresh. In regards to disposal, if you’re on city sewer, check with your municipality, some wastewater treatment plants already remove glycols, and in those cases they may tell you to dump it down a household drain. Worth asking.