Eight (Cylinders) is Enough? Too Many, Nowadays

(MoneyWatch)  Chasing better fuel economy, U.S. consumers are downsizing engines, as well as vehicles.

I recalled here the other day that "Mr. Turbo" at Sweden's Saab Automobiles was pushing smaller, fuel-efficient, four-cylinder turbocharged engines back in the late 1970s, long before anybody imagined U.S. prices hitting $4 a gallon. Back then, $1 per gallon was shocking enough.

Today, several automakers, including Ford, are getting on the turbo bandwagon, for both four- and six-cylinder engines. Volkswagen and BMW have also added turbo models.

That's making America's favorite engine, the red-white-and-blue V-8, look a little old-fashioned. V-8 engines, which made up 28 percent of the car and light-truck engines produced in North America in 2007, will shrink to 17 percent by 2014, according to consulting firm CSM Worldwide, and internal forecasts from auto supplier Borg Warner.

Six-cylinders will shrink in the short run, but grow overall, from 38 percent of the market in 2007 to 43 percent in 2014. The big gainers will be miserly four-cylinder engines, which will grow from a 31-percent share to 39 percent, an increase of more than 1 million units a year, according to Borg Warner's presentation at the 2008 Credit Suisse Global Automotive Conference in New York on Sept. 4.

Besides becoming more common, four-cylinder engines will also get smaller, according to Borg Warner. Some global markets offer tax breaks based on engine size, especially for engines of 2.0 liters of displacement or smaller. The unintended consequence is a nice variety of 2.0-liter, four-cylinder engines, some of which are turbocharged. Volkswagen has 2.0-liter turbos in a bunch of Volkswagen and Audi models, for instance. Borg Warner expects growth in the number of four-cylinders smaller than 2.0 liters.

Turbocharging produces more horsepower, without using as much gas as a bigger engine with more cylinders. My friend John "The Car Buzzard" Matras picked up on my reference to Mr. Turbo recently, and wrote a better technical explanation than I would have done, of turbocharging and its pros and cons.

All those new four-cylinder engines won't be turbos, but a lot of them will be. That's good news for Borg Warner, which makes turbochargers.