Chrysler Reveals Major Revisions to Pentastar V-6 - Car and Driver (blog)
However, the biggest single efficiency improvement, according to FCA engineers, is a revision to the engine’s variable valve timing, giving intake-side valves a two-stage lift strategy—low lift for routine power demands, high lift when the driver... Operating range of the variable-valve-timing system has been increased from 50 to 70 degrees to mitigate detonation during hot starts, improving operation of the automatic engine stop-start (ESS) function. FCA chose to continue with an upgraded port-injection system, citing added cost and weight as tradeoffs that go with direct injection. (According to FCA, the new engine will weigh 326 pounds in the Grand Cherokee, four pounds less than the current V-6. ) The engineers also looked at, and ultimately passed on, Fiat’s MultiAir induction system , for reasons of cost and U. S. market... Source: blog.caranddriver.com
