The Fisker Karma Showcases a Steel Fuel Tank

Fisker Karma

The 2012 Fisker Karma features a closed, pressurized steel fuel tank manufactured by Spectra Premium Industries. The tank is made from cold rolled, EDDS pre-painted zinc-nickel steel, ensuring compatibility with even the most aggressive fuels. The tank shell geometry is optimized to withstand the severe cyclic fatigue (pressure / vacuum) levels unique to EREV systems.

Fisker KarmaThe upper and lower shells of the fuel tank are 1.0 mm and 1.4 mm thick, respectively. With a fuel capacity of 10 gallons, the 14.7 kg (32.3 pound) tank assembly feeds a 260-horsepower, 2.0-liter GM Ecotec turbo engine that provides backup power to a 20-kWh lithium-ion battery which in turn powers two electric motors.

Through the use of a specially engineered blank and advanced forming analysis, Spectra Premium Industries meets the challenge of producing the deep, dual lobed shape required to package the tank in the vehicle environment. The tank also features a true 3-D weld flange. This fact, along with the considerable difference between the upper and lower shell thicknesses, requires a state of the art welding process developed by Soutec.

About the Strategic Alliance for Steel Tanks (SASFT)
The Strategic Alliance for Fuel Tanks (SASFT) is an international alliance of companies specializing in the various areas of fuel tank production, possessing a common interest in the development, optimization and application of steel fuel tanks for automobiles. SASFT was organized by the American Iron and Steel Institute in 2000 to bring together the diverse business disciplines involved in designing, manufacturing and supplying steel fuel tanks in the automotive market. For more information on SASFT, please visit