Not entirely. Ford owns 15% to 25% of stock in Cummins. You can
get the Cummins diesel in the Ford F-650 and F-750.
No, Ford Motor Company (FMC) at one time held less than 10% of
Cummins shares but at the present time does not own any part of
Cummins inc.
From my research, Cummins is an independent company with
publicly traded stock.