I have a 2009 Civic with 27K miles. At what mileage should I expect the maintenance minder indication for the coolant replacement?

 

Honda Genuine coolant is good up to ~60,000 miles as stated on the bottle. Assuming that is what is being used, you should be fine for a little while longer.

 

Do the newer Honda's use that orange crap. The same crap GM uses, (DEX-COOL). Or is it Green. I never change coolant unless I blow a hose or change a thermostat or something like that. If they use Dex-Cool then good luck. Air contaminates it, & if you mix regular anti freeze with it it will mud up everything in the cooling system, plug heater cores etc.
Just Great stuff.

 

Coolant doesn't last forever. Old coolant will corrode your engine because the corrosion inhibitors become depleted and ethylene glycol (the anti-freezing ingredient that is the major component of coolant) slowly oxidizes to form glycolic acid. Drain and replace it every 5 years if you haven't by attrition.