"Gas guzzler" is a relative term, dependent upon the basic point of reference. A hybrid will guzzle gas once the battery power depletes (zero gasoline use) and then the engine starts to run to generate propulsion power (using gasoline).
A 440 6bbl 'Cuda will guzzle gas compared to a 318 Barracuda.
Can't forget the mid-'70s one-ton Duallys, Chevy 454s and Ford 460s, which did good to break 8mph, unloaded, going down hill, with a tail wind. But then they'd "work" as a Prius never can!
Back in the later '90s, I was walking across the lot at work. Almost every car that GM sold back then, with either the Chevy 60-degree V-6 (3.1L, 3.4L single cam) or the Buick 3800 V-6 had an EPA highway rating of 29+mpg (27mpg on the supercharged 3800 Regal GS and Grand Prix GT), which they'd do on a trip. I happened across a new Nissan 2-dr little 4cyl car, with an EPA highway rating of about 23mpg. Where's the gas guzzler there?
Enjoy!
CBODY67