[Tom, F&L GoR]

The Evans system uses 100% glycol (forgot if propylene or ethylene). Glycol is a poorer heat transfer agent than water. However, it has a higher boiling point and I think part of the Evans system is controlled boiling. A phase change provides a very high heat transfer rate.

I would want to ask the Evans people what they say about corrosion protection.

Regarding future fluid changes - there are now "lifetime" coolants that don't need changing. Even so, the more typical modern coolant is 5 years/150,000 miles.

I admit to not having studied it enough to provide a real technical opinion, but be aware that some tracks do not allow glycol in the cooling system. If spilled in an accident or engine failure, glycol is slippery and difficult to clean up. You will want to call around to any track events to see what their policy is before deciding what to do.