But after a brief drive of the CX-7 diesel in Switzerland a couple of weeks back, we're convinced a U.S.-spec CX-7 diesel has the potential to be one of those rare vehicles that is greater than the sum of its parts. It's not just the gas mileage. It's the torque. With 295 lb-ft on tap at just 2000 rpm, the MZR-CD delivers the sort of meaty launch feel American consumers love. While the 2.3-liter gas turbo, which has 258 lb-ft available at 2500 rpm, delivers a distinct pause-two-three sensation as it spools up from idle, the diesel delivers useable grunt the moment you squeeze the accelerator pedal. The diesel CX-7 feels more alert, yet paradoxically, more relaxed, an ideal combination for a crossover.

Here's the thing: If Mazda does decide to bring the CX-7 diesel to North America, it will be faster and even more fuel-efficient than the model we drove in Europe. Under the hood would be the forthcoming Sky-D series diesel engine, a 2.0-liter four with twin-stage turbocharging that will deliver more power and torque than the 2.2-liter MZR-CD, and a 20-percent improvement in fuel economy.

The biggest hurdle Mazda faces introducing diesel motors in the U.S., says Kanai, is customer perception of the technology. "As an engineer, ideally I would want to introduce diesels, but I am not sure if it makes a business case," Kanai told Automotive News last year. He says Mazda would need minimum annual sales of 10,000 diesel vehicles in the U.S. to turn a profit.

The CX-7 alone is unlikely to account for the 10,000 units of Sky-D powertrains Kanai believes Mazda needs to make diesel viable in the U.S. -- unless the company takes the bold step of making a diesel CX-7 the premium model in the range, replacing the 2.3-liter gas-engined model in the lineup. Mazda sold just over 20,000 CX-7s in the U.S. last year, and 60 percent of those were the entry-level 2.5i model.