Yes and no. The fastest car you've ever driven is (and should always be) a rental car.
When I got married, we rented a Chebby HHR. Got 31mpg by the end...I was conservative but not quite hypermiling. Bachelor parties and all. I was far from the only one driving (sorry, Enterprise!). It was also brand new and tight with 7 miles on the odo when I grabbed the wheel.
Last year my company rented me a Ford Escape. Fairly nice machine, had a 2.0 EcoBoost. I did little other than put a few lbs in the tires and use CC at 65ish and got 36mpg. And that's including making it one of the fastest cars I'd ever driven
But back when I worked rental cars...I had a route and it was quite an interesting comparison for FE.
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'97 Honda Civic DX Coupe 5MT - dead 2/23
'00 Echo - dead 2/17
'14 Chrysler Town + Country - My DD, for now
'67 Mustang Convertible - gone 1/17