There's been alot of debate on why the ford driveline. The only real reason that I can determine is that the cost must be lower than using GMs crate engines. Some have theorized that it's about emissions of the feul efficiency hurting GMs ratings. However this would not be the case, as the final manufacturer (Southern) would take the resposibility of emissions, feul economy, and safety concerns, not the component supplier. Case in point-Honda supplies the v6 option for the Saturn Vue. Honda is not responsible for the emissions or feul economy, GM is.
