Porsche doesn't currently offer anything with fewer than six cylinders, but much of the German automaker's illustrious history was made with boxer-style four-cylinder engines, starting with the iconic 356. Following stories in September of a new entry-level Porsche model to slot just below the Boxster are new rumors indicating that the next-gen Boxster itself will be endowed with a new four-banger.

Four-cylinder BMWs are commonplace in Europe, but here in the States you can't buy anything Bavarian with less than six pistons. Inside Line is reporting that the German automaker may change that by adding the direct-injected 2.0L four-pot from Europe to the 3-Series. The 170-hp engine powers the 320i and 120i across the pond. The models are well-received there, and for good reason, too. The ultra-efficient powerplant averages over 38 mpg in the European combined test cycle while still providing the razor-sharp handling that is BMW's trademark.

There are some old-timers out there who think Cadillacs should have big fins and V8 engines who aren't going to like this one bit. Emerging reports suggest that the General's luxury division may launch a four-cylinder model for the American market by 2011.

According to sources speaking with Pickuptrucks.com, Ford is considering offering an EcoBoost four-cylinder engine on its F-150 pickup in 2013. The boosted mill is expected to displace around 2.5-liters, produce 260 hp and 300 lb.-ft. of torque, and would only be available on the two-door Regular Cab F-150 4x2 and 4x4.

Ford's rationale for equipping its workaday pickup with a turbo'd four is partially due to the rising cost of gasoline, but is primarily fueled by new CAFE regulations that will require light trucks to average 28.6 mpg by 2015. Ford has already decided to drop its 4.2-liter V6 for the 2009 model year, only offering the 4.6-liter V8, which produces more power and more torque, while still offering similar fuel economy.

Two separate reports out of Australia say that Holden is looking to maximize the Commodore's fuel efficiency in an effort to stoke sales. Both stories quote General Motor's Asia-Pacific vice president, Nick Reilly, but the separate reports, while sharing a common theme, come to decidedly different conclusions about how the General plans to proceed.

When the C-Class predecessor launched, it was known as the 190 and carried a four-cylinder powerplant underhood. Mercedes is now considering a return to four-pots in the U.S. market as the price of fuel continues to soar. MBZ is reportedly already testing a 1.4-liter carrying a supercharger, which is strange when you consider there's already a 1.8-liter blown four-cylinder on sale in Europe. The C180 Kompressor seems like it'd be the easy way to get fours back into the U.S. lineup, but Mercedes must have some other ideas driving the decision to develop the smaller 1.4.