"Rich256" wrote in message
Or you can say you are paying about $5.50 an hour to drive 70 instead of
60
( or earning $5.50, tax free, driving at 60).

That is for the saved 29 hours. For the full time it is more like 91¢ per
hour.


The "Myth Busters" did a segment on driving with AC or windows open. It
was
not very conclusive I thought. I think the windows open won but the guy
with the AC on was freezing. They were not diving at 70 mph either.

I think speed and car design would make a difference. On a smaller engine,
the AC would take more power as a percentage than a larger engine. Years
ago, I'd shut the AC off to pass another car or to struggle up a hill. On my
car, I cannot feel any difference. Compressors have improved.