Wheelies: The Bifuel Edition - NYTimes.com General Motors announced Wednesday its plan to offer a bifuel version of the Chevrolet Impala beginning in the 2015 model year. The car will be able to run on gasoline or natural gas, Daniel F. Akerson, chief executive of G.M., said at an energy conference in Washington. Mr. Akerson said that having the option to choose between two fuels would give motorists greater range - the bifuel Impala is supposed to travel 500 miles before needing a fill-up. Mr. Akerson hopes to woo environmentalists with claims that natural gas burns much cleaner than gasoline or diesel. General Motors A dockworker strike at the Port of Baltimore has delayed deliveries from automakers, like BMW, Mazda and Fiat, according to a report from Bloomberg News. About 2,000 longshoremen - members of the local union affiliate - held a walkout, citing a contract dispute between Local 333 of the International Longshoremen's Association and the Steamship Trade Association of Baltimore. Local 333 claims the association has refused to negotiate in good faith over a new contract. Meanwhile, automakers have expressed hope that the matter will be resolved quickly. Joel Ewanick, the former global marketing chief at General Motors, is speaking up after being dismissed last year. G.M. said at the time that Mr. Ewanick "failed to meet the expectations the company has of an employee." Automotive News reported that sources said that he mishandled a sponsorship deal with Manchester United, the British soccer team. Mr. Ewanick said this week that the deal was "a no-brainer," adding that he holds no grudges against G.M. (Automotive News) Ford's police interceptors are known for being quick, but as it turns out, even the ones not rated for pursuit missions are fast off the line. In an acceleration test by the Michigan State Police, the EcoBoost V-6-powered, all-wheel-drive Ford police interceptor - based on the Taurus sedan - beat the V-8-equipped Chevrolet Caprice and Dodge Charger interceptors, Ford said. The sedan went from 0 to 60 miles per hour in 5.66 seconds, compared with the Caprice's 6.01 and the Charger's 6.04. The all-wheel-drive Explorer-based EcoBoost interceptor variant made quick work of its competition as well, reaching 60 in 6.28 seconds, compared with the V-8 Chevrolet Tahoe's more sedate 8.22 seconds. With cars like the Cadillac CTS-Vsport and Chevrolet Camaro ZL1, General Motors has indicated that its head is firmly in the performance game. This week, Adam Dean drove a Camaro Z/28 around the Nürburgring in Germany, the 13-mile circuit that gives manufacturers bragging rights if their machines perform admirably. The modern muscle car posted a 7 minute, 37.4 second run, and despite wet weather, had a faster time than the 991 Porsche 911 Carrera S, the Lamborghini Murciélago LP640, the Lexus LFA and the Ford GT.