Well I drove 485 miles on a round trip this weekend, and still have 3 bars left to my tank!!!!!

Used the a/c all the way up to my cabin(210 miles) and noticed my tires seemeed low, they were only 24psi!!

Filled tires to 32psi and did not need the a/c on the trip back.

Had about 50 miles of city before I even left for my cabin.

I am very happy about this mileage I'm seeing.

My car uses the last 3 bars fairly quick so I'm just going to fill up and be kind to my fuel pump lol. But 500 would be easy.

Speed was 60-70, avg about 67. cruise most of the time.

I believe over 550 is very possible with no city and no stopping.

:thumbsup:

That kind of economy and power makes it impossible to bash the small block Chebby. Your car is about 10% heavier than an 8/6/4 car and easily beats it mileage wise and kills it in a drag race. Makes me want to finish my project using a Cadillac engine with a well calibrated fuel system and overdrive. I still think a Cadillac engine has the potential for great mileage AND power unless you start adding stuff that shifts the torque curve upwards in RPM.
Also wonder what the later powertrain in an earlier, lighter Fleetwood would yield.
I used to regularly get 400 and change miles from a tank with my '77 CDV and I thought that was hot stuff.

Wow, very nice! On the trip back from Ames IA this weekend, I got 206 miles to 1/2 of my 18 gallon tank. Which is 22.8 mpg if anyone cares....not really that good. If I can get 24-25 mpg on the highway, I should see between 432 and 450 miles to a tank.

That's great ! I think my FWB can manage to do your MPG . Actually, I haven't calculated used fuel yet . I have to say the car is impressing and if you are not lead footed and whatnot in other words should you not floor the car , you can really have an amazing MPG .