Jackal, it's no BS.
In 1979, I was working for the State of Illinois in Springfield. There were a few other Brits there. Most had just got there, and were in the process of buying cars. I got a 1977 Camaro Type LT. One of the other guys, Chris, bought a large 1967 Buick. I don't recall the model name, but it was an ordinary 4-dr car - saloon, or "sedan" as you guys call them. Remember that we had been used to paying more for fuel in Britain as you read this.
Chris was bemoaning the amount of fuel his Buick went through. I remember the conversation well. It went like this.
Me: "I see you've bought one of those huge monsters - what made you buy that?"
Chris: "It was going very cheap because of the fuel crisis"
Me: "Oh - what IS the fuel consumption in one of those?"
Chris: "9mpg"
Me: "9 miles per gallon??? wow - what do you get on the highway?"
Chris: "That IS the highway mileage. In town it's around 6mpg"
I'm just reporting what I was told, Jackal. You might argue that his Buick needed a tune up, but so did thousands of other cars. Speaking of which...
A ladyfriend I met had a 1974 Ford Thunderbird. It was in such a bad state of tune that it could
idle half a tank of gas away in 2 hours. Don't ask me how I know this.
A couple of weeks later, she took me to Springfield Memorial for emergency treatment - good job she filled up with gas before setting out!