MPG 1974 L48 350?

[74 stingray]

I have about 400 miles on my recently purchased 1974 L48 4-speed manual, and am averaging about 13 mpg. Is this what the rest of you with that powertrain are seeing? The car seems to idle and run very well, but I was expecting something in the 15-16 mpg range. Any comments and ideas are most appreciated.

 

[6880 Mike]

My '74 L-48 with TH400 would get about 18 mpg (city, highway, and interstate combined) when she was tuned. 14-16 was common on my daily commute at the time (no interstate travel).

 

[petes74ttop]

Hi 74 stingray and welcome to the forum. I get about 14 mpg too so I feel the same pain at the pump. Just aired up the tires to 32 psi from 26 and changed the motor oil to 10W30 from 30W. PG.

 

[milo30]

It's probably your gearing that is keeping you from geting the mileage you expected. I get about 12 to 14 in mine. I'm considering going to an OD tranny to help out mileage and wear on engine.

 

[Bill75]

Welcome to the forum.

That's about what mine used to get. Mine has 3:36 rear gears and it would run pretty high revs at highway speeds. I've changed my motor and installed a 5 speed and it gets 22 or so at 70mph with the air on.