That ol' four-banger has some life left in it yet: Automakers are tinkering with internal-combustion engines to try to get just a little more performance and fuel economy out of them.
That might not seem surprising until you consider how long they've been around -- basically, since the dawn of the automotive age -- and how many improvements they've already had made to them in the past few years, from variable valve timing to direct injection.
Now, Automotive News says automakers are going further, trying out such ideas as using excess heat to warm engine lubricants more quickly to reduce friction. Every little change adds up.
Source
USA Today