DETROIT — It is either a visionary approach to fuel systems, or a case of Chicken Little talking about the sky falling.
In either case, Walbro Corp. unveiled its plastic fuel system of the future, the 2000x Smart Tank, at SAE '99, held March 1-4 in Detroit. The tank, which is designed to limit evaporative emissions, sparked debate among fuel-system suppliers.
Fuel and vapor emissions already are tightly controlled by U.S. Environmental Protection Agency regulations. Those rules could soon grow even stricter, said Thomas Mathues, vice president of North American engineering for the Cass City, Mich.-based company.
The state of California's air regulations board, or CARB, is considering regulations that would require no more than 0.15 grams of evaporative emissions in a 24-hour period.
That amount — less than the amount of air inside a pingpong ball — would trigger the makers of plastic fuel tanks to redesign their products, Mathues said.
``The [emissions] requirements are way down already,'' Mathues said. ``Now, we expect more reductions on today's numbers by 2004.''
Walbro wants to respond now, he said.
The supplier's new fuel system eliminates many of the holes and joints in today's coextruded tanks where emissions can escape. Instead, many of the outer fuel-system parts will move to the interior of the tank.
Walbro's new fuel tank has an in-tank computer to provide fuel needed on demand. The six-layer tank, made from high density polyethylene, also includes fuel-pressure controls and devices, a high-pressure sensor to measure fuel volume, a vapor-collection system and a fuel reservoir and filter.
The entire integrated system could be ready as soon as mid-2000, Mathues said. And it would meet the new requirements.
Yet, while Walbro is touting its fuel system as a standard-bearer, other suppliers were not sold on the need to remake plastic tanks.
Sources at both Dearborn, Mich.-based Visteon Automotive Systems and Troy, Mich.-based Solvay Automotive said current tanks work just fine to meet more-stringent emission requirements.
Current blow molded tanks went through wholesale changes to meet strict permeability standards in the early 1990s, said John Thorn, fuel-systems technical specialist with Visteon. That was in response to the Clean Air Act of 1990.
``[Tanks] are the only component in the fuel system that has ever been tested with detailed data,'' Thorn said. ``With any new laws, there might be subtle changes in the sealing areas connected to the tanks. But the tanks themselves should be fine.''
If new regulations come into play, fuel-tank suppliers might also be forced to look at new barrier layers to protect against permeation, said Boney Mathew, president of consulting firm Mathson Industries Inc.
Current tanks are made with a barrier layer of ethylene vinyl alcohol. That layer might be replaced with fluoropolymers, Mathew said. Existing coextusion equipment would have to be adapted, and a surface treatment or tie layer would be needed for the material to mix with HDPE, he said.
Many manufacturers also are considering integrated fuel tanks, incorporating fuel and vapor lines, fuel rails, throttle bodies and filler caps. While those would not provide lower emissions, they would take out weight and save costs, Thorn said.
At Walbro, the move toward a Smart Tank might be part of the company's push to build its reputation after troubling times. In 1997, the fuel-system supplier recorded $36 million in annual losses and more than $40 million in write-downs to increase efficiency.
Walbro Chief Executive Officer Lambert Althaver resigned, sparking some analysts to question whether the company would be sold.
But a shift to ``leaner thinking'' is now paying off, said Walbro North American President Thomas DeJong. Sales were up by 9 percent in 1998, to $678 million, and the firm recorded $40 million in profit.
The company also has about $80 million to $100 million a year in new contracts on its books for the next three years, added Walbro Chief Financial Officer Michael Shope.