Years ago I saw a Caddy with weird looking valve covers, and on the side it said V4 6 8.
The owner explained it was some (at the time) new fangled method of increasing fuel economy.. the engine would run as a V4 for around town driving, as a V6 when you needed a little more power, and as a V8 when you really put your foot into it.
Most people i've talked to about it said the engine wasn't used but in just a few model years, and the idea was eventually scrapped due to numerous reliability issues.
Flash forward to present day.. on a commercial for the new Chevy Impala, I saw that a simular idea was being used in the SS models, now called "DOD" or Displacement On Demand technology.
From the chevy website:
A 303-hp small block V8 is standard in SS and features Displacement on Demand (DOD) technology that uses eight cylinders when you want more power, four cylinders when you need better mileage — delivering an EPA estimated, petrol-pinching 28 MPG highway.
What do you think?
