Editing Variable valve timing (section)

==Challenges==
The main factor preventing this technology from wide use in production automobiles is the ability to produce a cost-effective means of controlling the valve timing under the conditions internal to an engine.{{citation needed|date=May 2013}} An engine operating at 3000 revolutions per minute will rotate the [[camshaft]] 25 times per second, so the valve timing events have to occur at precise times to offer performance benefits.  Electromagnetic and pneumatic [[camless]] valve actuators offer the greatest control of precise valve timing, but, in 2016, are not cost-effective for production vehicles.{{citation needed|date=December 2023}}