BMW To Sell Us 4-Cylinder Diesels

WOODCLIFF LAKE, New Jersey — BMW has plans to bring a four-cylinder diesel engine to the United States, said Tom Baloga, vice president of engineering for BMW of North America.

"You're going to see it of course in the 3 Series," he said, speaking Tuesday to journalists at BMW's North American headquarters, "and the 5 Series is a good possibility. If the performance [of such an engine] is sufficient in the X3, U.S. customers would likely accept it in the X5 as well." Although Inside Line reported earlier that all future U.S. diesels would be all-wheel-drive , Baloga said this won't necessarily be the case, although the take rate on all-wheel drive is indeed high across the U.S. fleet.

Eventually, he added, BMW hopes to achieve 10-20 percent market penetration for diesels in its U.S.-market cars — still a drop in the bucket compared to the 70 percent penetration in diesel-subsidized Europe.

This turbocharged diesel four-cylinder would be a 2.0-liter (as in the European-market BMW 320d), but BMW wouldn't target Volkswagen's TDI power plant in fuel economy or market positioning.

"We would be focusing to make sure we get the performance that people expect without squeezing every last mile per gallon out of it," Baloga said. "I don't think we would ever consciously look at [the VW Jetta TDI's] numbers and say 'we have to beat that.'

"This engine needs to match the acoustic qualities of a 6-cylinder, and it needs to match the performance, as well as performing better in terms of fuel economy and emissions. The target is to produce enough horsepower to be comparable [in performance] to our N54/N55 six-cylinder turbos."

Meeting this performance threshold won't be easy, and Baloga acknowledged a reduction in vehicle weight will be necessary. But he's convinced it's doable. "Our four-cylinder diesel will be so good that people will readily accept it as a replacement for six-cylinders," he said.

Baloga wouldn't get specific on timing, but he expressed optimism that looming California plans to tighten emissions standards further after 2016 won't impede BMW's ability to offer diesels in the U.S.

"It's important to note that Europe is catching up with California regulations," he said.

Baloga wouldn't say whether BMWs with the four-cylinder diesel would use selective catalytic reduction (SCR) treatment (a refillable on-board urea tank, that is) as in the BMW 335d and BMW X5 xDrive35d, or just a diesel particulate filter (DPF) as in the Jetta TDI.

But he hinted at the latter, noting, "The strategy for after-treatment is to make it less expensive and less trouble." Generally speaking, he said, smaller-displacement diesel engines with less horsepower can get by with just a DPF.

Inside Line says: Good news for anyone who doubted the future of diesel in Ultimate Driving Machines. — Erin Riches, Senior Editor