1985 454 mpg

[Dragonfly85]

1985 454 pulling 28' Fleetwood Pace Arrow. 100 gallon fuel tank, from San Diego to Sacramento via I-5. Anyone know how many miles I can expect from those 100gal. Of Lucas Treated Unleaded gasoline? Projections for untreated gas are still helpful. MAHALO! 

[peterara]

You'll probably get anywhere from 7 to 10 miles to the gallon

[Truckzilla]

I had a '88 C30 crew cab dually with TBI and I'd be darn lucky to get 9 MPG going down hill empty and not pulling a thing!

[ehjorten]

I say close to 7 mpg.  You should make it just fine without filling-up.

[Takilma]

Flat land freeway, you might even make 9 mpg. I have a 454 that gets 9 whether it's pulling a load or loafing, that's with a Holley spreadbore with the secondary vacuum spring set to delay the secondarys as long as possible....( which incidently was NO improvement over the stock Q-jet that leaked out the plugs on the bottom, making easy starts with a bunch of fuel in the manifold every A.M.)

[timthescarrd]

The engine and what you're hauling alone don't determine MPGs, there are so many factors that go into it.  Tire size, gear ratio, transmission, how fast you drive, ambient temp, humidity, altitude, condition of the engine, wind... But 7 MPG is a pretty good guess