Well, the simple answer is... if it doesn't get into the red and the warning light doesn't go on... the car isn't overheating. :rolleyes: It's simply venting coolant for some other reason, which has been heard of before with these cars. If the system wasn't properly bled and has air in it, or if the pressure cap is bad, it could be boiling somewhere and building pressure that the cap will let off out the vent tube, hence loosing coolant. Try replacing the cap on the overflow tank and make sure the system is free of air.

As for why they run so hot, as was stated it's for a cleaner burn to get better gas mileage and less emissions. Every new car is like that.

The difference between the dex cool and the old style green coolant is only in the anti-corrosion and lubricant additives. The actual cooling and anti-freeze components are the same (ethylene glycol). Dex cool is actually different now (new formula) and really it's just a long life coolant that lasts for 5 years or 100,000 miles. There are several brands on the market and any of them can be used. Red, green, yellow... doesn't matter as long as is says "long life".

You actually CAN mix the long life coolants with the old stuff also... it's just that if you put the old stuff in a system that came with long life coolant, it's not long life any more and has to be changed every 2-3 years. The corrosion inhibitors in long life coolant are organic acid based. The old coolants were silicone based and that stuff sticks to the wall in the coolant passages, so once you fill it with that, there's no getting it out unless you empty the whole system and chemically flush it, and take the engine out and hot tank it. lol Not an easy job! The only real important thing with the long life coolants is to make sure they are properly filled and bled and free of air. They tend to build up gunk when they get hot and are exposed to air.

Is the engine coolant system holding pressure ?

If it is "boiling" over at 200°F/93°C: it sounds like there is a leak in the coolant system.
(Remember water boils at 100°C/212°F under normal atmosphere pressure.)
Most commonly the Engine coolant reservoir cap is not holding the 15 psi needed; & a new cap is needed.

agree with aaron on the pressure cap. if it reaches 220, it will begin to boil out if it is not under pressure, the pressure raises the boiling point, no pressure, lower boiling point, 220, whitch is not high enough to turn on your fans.

I bought a new cap and put in the Dexcool and it solved the problem. Thanks for the replies.