I’m Impressed- Fuel Economy


Well-Known Member
Dec 26, 2021
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Gurnee, IL
So today I drove my new to me 1973 Imperial back from Wisconsin, it was a 190 mile trip for the car. It was amazing to drive but when I stopped to fill up, I was shocked. 14.59mpg on the highway from a 5000lb car and going 70-75mph the whole way.
IF you could have driven it at 55mph with the cruise on, you might be even more impressed.

Don't remember seeing it. Edit: just spotted your comment on the other thread.
When the national speed limiit was 55mph, Fenner Tubbs Chry-Ply in Lubbock, TX took each one of their demo fleet to do some highway mpg checks. The '74 New Yorker 440 TQ did 20.66mpg and the '74 Newport 400 2bbl did 20.33mpg. They filled them up at the Shell station across from the dealership and then drove them south, out of town, toward the edge of the Caprock, turned around and headed back to the Shell station for a re-fill. Using the factory cruise controls on the highway at 55mph posted speeds. That is what I was referring to, not that you should obstruct traffic.

Take care,
Back in the day, that is when it was new, my father’s ’70 NYer with OEM 440 would do 14 mpg all day running at 62 mph (100 km/h, it had a kph speedo). I once tiptoed with it just to find out how low it would go. 16.8 mpg was the best I could get, but then you had to keep it at 50 mph at the tops.
This is with everything stock 1973, EGR, OSAC, and the evap system. I will be bypassing the OSAC and be doing a tune up. I will see if it increases.
Yup, I'd say your Imperial is dialed in...my 74 used to get 15 mpg at 70-75 mph.
You would spend less buying my TB then restoring your 72. Sorry just thinking out loud. I will go away now.
My old '78 NYBS got 22 mpg on a 110-mile trip on the I-44 turnpike from OKC to Tulsa and back. That was at 70-75 mph. It was a wonderful road car.

I've got over 20 with the Imperial convertible, as well. People think these are all 7 mpg gas hogs, and obviously they're not.