[kach22i]

Back in 1983 I put a large chin spoiler on my shortbox 1976 Ford Econline van.

I don't recall it improving gas mileage, but clearly remember it helping in crosswinds.

The van used to wander like crazy in the wind while on the highway. After installation of the massive chin spoiler I could take my hands off the wheel and it would drive straight.

The truck had a lot of miles on it, the whole front end was terribly loose. I even got a ticket after I hit a pothole and it launched me into the curb.

The three on the tree shifter was always binding up too, I had to crawl under it and move the leavers after it jambed up (more than once).

My conclusion, less air moving under the van was a good thing, despite it looking like a brick.