honda type 2 coolant is formulated specificially for all aluminum engines. some antifreeze, although labeled as safe for aluminum engines, is not compatible with hondas aluminum alloy. this is especially prevalent in the elements with clogging heater cores(it's only about 1500 vehicles). the coolant used in certain vin specific elements was contaminated from the factory (although honda does not admit it is at fault) and caused massive corrosion build up in the heater core and radiator. (replacing that heater core means removing the entire dash assembly btw)
most domestic coolants have abrasive silicates and borates which adhere to the water pump seal causing premature seal failure and leakage down the road. this silicate tends to settle and collect in the coolest parts of the cooling system. this causes crud to build up and eventually block coolant passages blocking coolant flow and reducing cooling capability.
borates tend to cause pitting in the cylinder head.
keep in mind silicate inhibitors are difficult to stabilize - this reduces coolant shelf life. silicate was added to coolant for it's aluminum protection characteristics, but long term durability was never tested. other coolants simply don't contain the combination of additives needed for long engine life and water pump seal lubrication.
honda coolant does not use silicate because of the reasons listed above. although it has aluminum corrosion protection characteristics, it is not heathly for coolant seals and breaks down and collects too readily. honda uses an organic corrosion inhibitor instead of silicate. corrosion simply does not occur in the cooling system with honda coolant.
i have first hand proof of this by doing countless t-belt/water pumps and loving the lack of problems with the cooling system. however, when vehicles on their 2nd timing belt come in(after having the first t-belt/water pump done aftermarket) i find leakage from the water pump seal and corrosion build up int he radiator tubing.
if you insist on using aftermarket coolant be sure it does not contain silicate or borates and that it claims it's specifically for all aluminum engines if not honda/acura or import engines only. that will be your best shot at prolonged protection.
Anti-Freeze - Honda-Tech