> Larger displacement engines are almost invariably in larger, heavier, vehicles. This isn't even a good approximation because turbochargers (which nearly all

> Larger displacement engines are almost invariably in larger, heavier, vehicles. This isn't even a good approximation because turbochargers (which nearly all heavy, diesel vehicles have) significantly increase power at the same displacement. The 5 liter Mustang weighs less than 4000 pounds. Here's a >10,000 pound bus with a 3.2L diesel engine: https://www.tescobus.com/bus-for-sale/collins/school/ https://www.tescobus.com/bus-for-sale/collins/school/