Shell starts selling 'premium-plus' gas

Mark Phelan | Detroit Free Press

A new, more expensive grade of premium-plus gasoline that goes on sale at Shell stations nationwide could signal a new round of competition as oil companies add new features to their fuels.

Shell's claims include longer engine life and improved performance.

No independent analysis is available of Shell's claims for the fuel, Shell V-Power Nitro+. However, two independent fuel and engine experts say new additives to gasoline could reduce engine wear and improve efficiency.

"Nitro+ adds protection against wear and corrosion to the detergents our gasoline already contains," said Shell researcher Ed Nelson. "Fuel comes in contact with moving metal parts in pumps, cylinder rings and injectors. Nitro+ reduces wear" by adhering to those parts. It also keeps water in gasoline from adhering to the metal parts to reduce corrosion.

Shell demonstrated reduced wear and corrosion with standard industry lab tests, Nelson said. The fuel also has more detergent properties to prevent waste buildup in the engine. There's no need to use premium unless your vehicle's manufacturer recommends or requires it. Check your owner's manual or the label inside the fuel door if you're not sure.​

t's best when a company provides data to substantiate claims for a new product, of course, but Shell's claims look plausible until there's independent evidence to support or disprove them, independent experts say.

"Shell is taking their premium fuel and moving it up," GM fuel specialist Bill Studzinski said. "Reducing wear can help maintain optimal performance through the vehicle's life," which will be increasingly important as tougher fuel economy and emissions standards come into play.

Lower internal friction could make vehicles more efficient, said Harold Schock, mechanical engineering professor and director of the energy and automotive research lab at Michigan State University.

"Half the friction in an engine comes from the cylinders and piston rings," Schock said. "Reformulated fuel could make a difference" there and in high-pressure fuel injection systems.

Shell isn't saying how much more V-Power Nitro+ will cost compared to other grades. Other grades of Shell gasoline will have lower amounts of the new chemicals. Shell hasn't made any claims about their impact on engine wear and corrosion, or said anything about price changes for its regular and mid-grade gasolines. There's no change to any of the fuels' octane level.

Shell hired hyper-miler and blogger Wayne Gerdes to drive a Dodge Charger modified to run Nitro+ on one side of its V-6 engine and competitive premium gasolines on the other. Gerdes will drive 5,000 miles on a winding cross-country route that will hook up with a convoy of celebrity drivers in BMW M3s in New York City before setting off for Los Angeles.