BenK wrote:
Also why I recommend NOT going a hair past 5 years or 100K, whichever comes first
Actually flush every 2-3 years no matter American Green or OATs/HOATs.
More so if you open the cooling system...OATs and HOATs systems are
NOT meant to be opened but to flush
That $28/gallon price pales compared to an engine rebuild...
Flushing no longer helps once the clogging has started. I work in a transit fleet and know first-hand that flushing doesn't solve anything. Part of what's going on is electrolysis in the radiators causing depositions to form, mainly a problem on the brass/copper style radiators. Our aluminum radiators don't have any issues though, and we don't change the coolant on those radiators either (Coolant is around 7 years old at this point and is just the regular ethylene glycol type {non-oat}). Just adding additives to ensure that the coolant is still providing the lubrication and corrosion inhibiting properties that it should provide. Our vehicles also have coolant filters. It's just something to put up with. The engines don't seem to have any issues with clogging or buildup, only the radiators.
Personally, I'm all for OAT coolants because of their extended life with no need to really add any additive (wish we would switch at work, but we have legacy equipment that doesn't permit it yet). Truckers run their OAT equipped HD trucks for 500k miles plus before flushing. It is true though, that when the fluid is replaced, it must be done the right way or else very bad things can happen.
