4. Conclusion

In the century since the spark-ignition engine was first developed, performance has improved thanks to advances in ignition and carburetion. These two systems are now fully automated, and still offer scope for further progress.

Variable distribution is another avenue for development.

Many technologies have been developed and are now widely used.

The desire to control valve timing parameters naturally led to valve lift control. Switchable systems were developed, but are now increasingly being replaced by systems offering continuous lift control.

Lift control offers substantial fuel savings, but this potential is only fully realized when combined with a variable timing system. This is what automakers are now offering.

In the energy and environmental context of the beginning...