A few weeks ago I started tracking the MPG on my 1982 D150 with HEI and a new Weber 38. The first week I got 17 MPG, then 15, then 13.5.. This decline happened even though I was driving conservatively trying to improve mileage.

Come to find out,, the air filter that comes with the weber carb gets dirty and restricts airflow extremely fast!!! The air filter got dirty and affected performance in only one week of driving to and from work. (approx. 32 miles per day).

So,, off comes the Weber air filter,,.. (replaced with a universal 5 1/8 inch air filter)
My MPG are back!!! I don't have actual numbers yet, but so far I have driven 250 miles since my last fill up. And I still have about 1/4 tank left. (20 gallon gas tank)..

If anyone is thinking of getting a Weber, make sure to get the air filter adapter too.

_________________
Slant power!!!
At least I try...