Hello and welcome. Start a post in sport cruisers tiltled "Fuel burn "92 290 twin 4.3s"?
I will give you a pretty good idea....about 12-14 gph at 3500rpm ( 6-7 gallons per engine per hour).
I will give you a pretty good idea....about 12-14 gph at 3500rpm ( 6-7 gallons per engine per hour).