Losing a bit of Anti-Freeze

[Rob175]

I own a 98 Boxster with 79,000 miles. I ONLY drive it in the summer months (about 4 to 5,000 miles/yr), it never sees rain or snow. A few times during each winter, if the roads are dry and the salt has been washed off the roads I'll take it out for an hour just to run it.

Question...... Once about every two years, the "low coolant light" will blink indicating its coolant level is low. Typically I add only about 1 to 2 cups (never more than 2 cups) of 50/50 anti-freeze and the light goes off for another couple of years (8-10,000 more miles).......IS THAT NORMAL?

I have replaced the coolant cap several years ago, there are no pools or spots of coolant on the garage floor, no moisture or coolant in the trunk and the car runs great and the temps are always within the normal operating range.

Normal? Concerned? Have it looked at? Does coolant evaporate ever?......any thoughts?