The new Mazda6 is available with one of two engines, and both offer capable performance for what they are. The base engine is a 2.5-liter four-cylinder that produces 170 horsepower (a cleaner version that makes 168 hp is sold in California and other more-restrictive states). The optional 3.7-liter V-6 makes a healthy 272 hp.

Mazda expects the four-cylinder to account for 70 percent of sales. It's a smooth engine, albeit one that doesn't make the greatest sounds. It offers decent but not overwhelming power, and it didn't have trouble maintaining a 70-75 mph cruising speed on the highway.

The four-cylinder teams with a standard six-speed manual transmission — which replaces the five-speed used in the previous version of the car — or a five-speed automatic.

The manual transmission offers an enjoyable shifting experience. The gear selector moves between gears with a solid yet slick feel, and the short-throw shifter allows you to make quick shifts. Overall, it's a very precise gearbox.

The clutch is also worth highlighting because it's very easy to get used to it; you'll be modulating the gas and clutch pedals to hold the car on inclines before you know it. The pedal doesn't require an excessive amount of pressure to depress, but in heavy stop-and-go traffic my left leg started to tire nonetheless.

A manual typically makes a lightly powered engine perform better than it would with an automatic, but with the Mazda6 the manual does more to expose the four-cylinder's lack of low-end power than it does to hide it. Accelerating in first gear from a standstill yields modest response unless the engine is revved very hard. It's not until you get some momentum and shift into second gear that the four-cylinder begins to pull with more authority.

I also drove an automatic-equipped four-cylinder sedan. The transmission didn't make any unpleasant shifts, but I was even more impressed with its clutchless-manual mode; nudging the console gear selector forward for downshifts and backward for upshifts elicited a nearly immediate response from the transmission without any delay in shifting — a big turnoff that's often associated with these things.

I drove the V-6 model, too, which is only offered with a six-speed automatic transmission (a manual was available with the V-6 in the previous-generation Mazda6). The extra power of the V-6 is most appreciated when accelerating at highway speeds, around 60 mph; the sedan lunges forward with an urgency that's just not there with the four-cylinder. Interestingly, the six-speed automatic's clutchless-manual mode doesn't offer the quick response of the five-speed automatic that's teamed with the four-cylinder — there's a delay between when you nudge the gear selector and when the transmission shifts.

As with its steering system, the Mazda6 doesn't demand much effort from the driver when braking — pressing the pedal lightly brings strong, natural response.