Actually when I'm on empty on my 52 GMC 3/4 ton, it'll swallow about 15 gallons. But unless you're on a long drive to burn a little of it off, it'll leak back out with heat expansion. So you might be safer sticking to 13 gallons or so.


52 GMC 3/4 ton pickup
68 Big Block Vette
68 455 Firebird