Engine coolant for Honda Odyssey 2005

I have been told that only Honda coolant purchased from the dealer can be safely used in this vehicle;that aftermarket brands will damage the engine over a time period. Is this true? I would like as much feedback as I caan get on engine coolants used in our modern cars & trucks. What options do I have? Will soon be due for Manufacturers recomemded coolant change.

Yes, only use Honda coolant. Do not use coolants that say "compatible with all makes models and colors. Only use Honda coolant. Why are you hesitating to buy Honda coolant?

I am hesitating because I want to know why Honda engines are different from other manufacturer’s engines and require special coolant. Can you answer this question?

Honda is not the only car that has their own fluids.  They have chosen to use some material or design that other fluids will not work well.  Engineering is a matter of a lot of choices.  

Stick with what Honda tells you to use.

Before you move on, check the owner’s manual to make sure what you were told is correct. Sometimes dealer have a habit of not telling the whole truth in order to make a higher profit. Get out the owner’s manual and check out what it says.