Mazda's renowned zoom-zoom driving enjoyment comes with this refined Mazda6. Purists might complain about the lack of availability of a manual transmission with the V6 engine, but the sequential automatic does have a manual mode. And besides, there's nothing wrong with the four-cylinder Mazda 6i Sport.
Automatic and manual transmissions have well-spaced gears to make the best of the four-cylinder's output. The shift and clutch action on the close-ratio 6-speed manual show Mazda's sports car abilities without any sports car compromises.
The 2.5-liter four-cylinder engine, with 170 horsepower, gets the job done just fine, with the best coming on as the rev counter swings through the 4500-4800 rpm range and keeps pulling to near redline. It's plenty to get the Mazda6 around town or up a hill and cruises on the highway effortlessly at less than 3000 rpm, regardless of transmission. We never wish we had another hundred horsepower when driving it.
The 3.7-liter V6, with 272 horsepower, has loads of mid-range torque and delivers better acceleration than the 2.5. In fact this engine is larger and more powerful than its competitors. And it delivers good, if not class-leading fuel economy: 18/27 mpg for the 2011 Mazda6, increased from 17/25 for the 2010 model.
Each Mazda6 model has its own calibrations for the same suspension system, and they tend to feel more buttoned down as price and engine size increase. But a lot of this can be traced to tires, and a four-cylinder car with the 17-inch wheels is arguably the most fun on a winding road because it's a couple of hundred pounds lighter than the V6 models. But the standard 17-inch wheels only come with the automatic transmission; if you want the full sporty effect, with the 6-speed gearbox, you'd have to order the i sport and then get aftermarket wheels and tires, because the 17-inch alloy wheels aren't a stand-alone option.
At the top extreme, a V6 on 18-inch wheels has plenty of grip and surprisingly good sharp-impact rejection (think lane-divider dots) but it is on the firm side, not recommended for lousy infrastructure, and some road noise seeps in to the cabin. All the models have stability control, but it doesn't engage easily, suggesting there's a lot of stability inherent in the handling.
The closest competitors in the grip and ride components would be the Malibu V6 for ride, Altima V6 for fun, four-cylinder Accord for fun, Camry for commuting comfort, and Jetta for interior design. The Mazda6 leans toward the fun end of the spectrum, while maintaining a good ride quality.