some evaporation

[edwardh1]

many of the cars I have owned seem to lose about 1/2 cup per year of antifreeze
I ive in a hot climate- is that normal? Can never see any leak but the overflow jug always loses just a little over a year

 

[MarkC]

Kinda normal. Might check and make sure the water pump seal isn't seeping.

 

[Ray H]

Ethylene glycol has a very high boiling point. It's the water content of the diluted mixture that slowly evaporates. If you're certain you don't have a leak, topping off with distilled water is acceptable to maintain the 50/50 ratio. 1/2 cup loss per year is probably not from leakage. If you're still concerned, invest $20.00 in a used oil analysis - if there's antifreeze present in the oil, the lab will point it out in the report.