I seek one too. 87 carbed sube. Must be dynamical. I can go from mini dragster 20s mpg into the high 50s. all same engine, same carb same everything. Real engines do this, ECUs don't
<-as you can see its a blue serious face versus ->
I had heard or maybe even seen the old mpg computers in a gm cadillac or maybe pintiac, thay had strange gadgets... anyway, the limit was the problem indeed. they used alot of fuel back then...