9. Cadillac 8-6-4 Engine
Back in the early ’80s when fuel efficiency and cost savings were imperatives in the car game, most manufacturers were experimenting with various different engine and drivetrain options. Oldsmobile went the diesel route by introducing the notoriously poor-performing 4.3-liter V8 and then the improved 5.7-liter V8. However, Cadillac decided to install a fancy electronic cylinder deactivation system in its gasoline V8s.
When cruising around town, the car would only use four cylinders and the rest would deactivate, stopping fuel delivery and shutting down the spark plugs. When the driver needed more power, two more cylinders would activate, making the engine a V6. But when the driver pushed the throttle to the end, all eight would fire up to deliver full power. Unfortunately, as soon as the first examples arrived, problems started because the electronic system was unreliable. The engine tended to get stuck in one mode, usually four-cylinder. After a few years on the market, Cadillac discontinued this option, but it took even longer for the company to recover from its lost reputation.