Anyone have a good understanding that can explain the whats & whys of the new vehicle anti-freezes? I think they're commonly referred to as colored products. Orange-Red-Yelow-etc, depending on vehicle. I believe they are also referred to as extended life products.

However, we've gotten along just fine for many yrs w/the cheapest Farm & Fleet stuff which is green ethylene glycol (aka anti-freeze). However, now you are not supposed to mix any of the colored (usually from vehicle factory) w/the the old plain-jane a.f.....why?

I asked our trusted friend @ local radiator shop his opinion. He feels if vehicle is still under warranty, you'd better use their colored product. Otherwise, he recommends periodic flushing & he replaces w/plain old anti-freeze. That sounds fine w/me. However, he warned, do NOT mix the colored product in the radiator w/any of the old plain stuff unless it's an emergency. Now, he also suggested that you can buy a grade of anti-freeze that WILL mix with anything. I did buy that from F&F on Sat @ $10/gal. You mix it @ 50%.

My question....why? What's the difference? Why won't they mix, or what happens that could be bad? Be advised, the answer of BECAUSE! is never acceptable to me.

So-anyone know for sure? Or-do you feel it's all just marketing ploys?