Does variable valve timing really improve gas mileage?

Question

Does variable valve timing really improve gas mileage?

Answer 1

Variable valve timing helps the engine work more efficiently over a broader rpm range.

For years camshafts were designed to work at their best in a certain rev range, that is why highly tuned high revving engines had a rough lumpy idle, and low output engines have a smooth idle and are easier to drive in traffic or in town.

Variable valve timing goes some way to getting the best of both worlds. Ignition timing has been variable for many years now, both improve the efficiency of the engine and yes that improves gas mileage.

The downside is is increased complexity and therefore cost of building such an engine, but the fuel savings offsets the initial expense over time, and the car is more pleasant to drive.

However if you take advantage of the increased performance you wont save much gas!.

Answer 2

They were originally designed to make the car more powerful (by letting it breath better).

But anytime an engine breaths better it also improves MPG.  My 94 Civic has VTEC (variable valve timing) and has plenty of power AND gets 41 mpg

Good Luck...

Answer 3

No. It makes it more powerful in the upper RPM range. If you are driving for economy, you never get that high anyway.