I've used the phrase "runs like a dog" to mean that my car is on its last legs and can't, sometimes, run anywhere near as fast as a dog can.
Can anyone shed light on where this meaning of the phrase came from?
The Google NGram viewer says that "work like a dog" is much more common.
According to the Online Slang Dictionary, one slang definition of dog is "something of poor quality or a poor performer."
It's sometimes used to refer specifically to a car of poor quality, as in The Dog and Lemon Guide. So to say a car runs like a dog means it runs like a bad car, in the same vein as "My car runs like a lemon" or "My car runs like a clunker."
I'm also familiar with the phrase, "She's a dog," to describe a car or truck that has lost it's 'get up and go'. I don't think it refers so much to running speed, (some dogs are known for speed) as the fact that it doesn't always respond when you expect it to, i.e., when you step on the gas. Like when you say, "Here, doggie," and the doggie glances over at you and then goes back to his sniffing, or napping, or whatever.
“Dog” is derived from “doggie” that is a 1880s Western cowboy parlance used to describe calves as they get herded down the trail.
Calves tend to be slower in the herd so these subpopulation of the herd runs slower much to the exasperation of the backline cowboys into saying “git along doggies”.
Hence, the morphology of “Runs like a dog” began around the beginning of automobile era which typically then had a maximum speed of 8mph.
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