Yes, it’s in the title of a Phyllis Diller book. But this is not about the grand old girl.
I have never before heard this phrase - the only use I found was a review of a Mercedes gas guzzler, referring to its “smart” fuel economy during start/stop.
That would seem to be “nice touch, but REALLY besides the point”
I’m 63 and raised in OH and IN - have been in CA since age 30. If you know the term, where/when did you pick it up?