Deciding that four is better three, GM announced that production versions of its upcoming Volt plug-in Electric will use a new naturally-aspirated 1.4-liter inline four gasoline engine as a "range extender" in place of the turbocharged 1.0-liter three-cylinder that had previously been shown in the prototype.
In confirming the switch, Larry Nitz, GM's Executive Director of Hybrid Power Engineering, pointed out several reasons why this new 1.4-liter, which is part of GM's global Family Zero engine range, was simply a better fit for the Volt application. For openers, despite the additional displacement, it will deliver better fuel economy numbers in a steady-state operating mode and offer greater output. Beyond that, this new super-clean and efficient four-cylinder is inherently quieter, smoother, better balanced and will provide more seamless transitions when the Volt does changeover from pure electric to extender-enhanced modes. If that's not enough, the engine is also lighter and less expensive to build than the turbo three-cylinder.
The move to this new global 1.4-liter for the Volt should also yield significant economies of scale for GM, as a turbocharged version will power the 2011 Chevy Cruze, a subcompact sedan that will slot in between the Aveo and the Cobalt in the division's lineup. The engine will also be used in number of other future products, and all production will come from a new assembly plant that's currently under construction in Flint, Michigan.