13. Cadillac 8-6-4 Engine
Back in the early ’80s when fuel efficiency and cost savings were the most desirable features in the car sales game, most manufacturers were experimenting with various engine and drivetrain options. Oldsmobile went the diesel route by introducing the notoriously bad 4.3-liter V8 and then the slightly better 5.7-liter V8. However, Cadillac decided to install a fancy electronic cylinder deactivation system on their gasoline V8s. When cruising around town with the new deactivation system, the car would only use four cylinders.
The rest would deactivate electronically, stopping the fuel delivery and shutting down the spark plugs. When the driver needed more power, two more cylinders would activate, making the engine a V6. However, when the driver pushed the throttle to the end, all eight would fire up to deliver full V8 power. However, as soon they delivered the first examples, problems started. Simply, the electronic system was terribly unreliable, so the engine tended to get stuck in one mode, most often as a four-cylinder. After a few years on the market, Cadillac discontinued this option, but it took a long time to recover from the damage to its reputation.