THERMOPLASTIC tanks have grabbed nearly half of the North American market for fuel tanks and appear to be on their way to at least three-quarters of the business within the next several years.
In Europe, penetration is already at that level and is expected to reach 90 percent within five years.
Kautex Werke Reinold Hagen AG of Germany and Belgian rival Solvay SA are making big gains in North America. Each claims to be the global-market leader in plastic fuel tanks.
Plastic tanks have seized all of Chrysler Corp.'s business and about 40 percent of new General Motors vehicles.
'We're pretty much moving toward plastic on all our new designs,' says Phil Yaccarino, fuels systems manager at the GM chassis center. 'The trend over the past 10 years, industry-wide, will continue.'
The flight to plastic in North America is dramatic. In 1996, steel tanks had 63 percent of North American volume, says Jane Warner, president of the North American arm of Kautex Werke Reinold Hagen. The plastic-tank giant was acquired by Textron Automotive Co., a unit of Textron Inc., early last year.
By 2002, Kautex says that plastic will account for 74 percent of the North American tank market.
Solvay believes it may take until 2004 for plastic to get three-fourths of the North American market.
In Europe, high density polyethylene emerged as an alternative to steel about 25 years ago. Now 75 to 80 percent of the European market is plastic. Within five years it will be 90 percent, according to Kautex Textron projections.
Because of higher gasoline prices and smaller cars, European carmakers long have had a greater need for plastic tanks. They reduce weight and can be shaped to fit into tight spaces.
In North America, Solvay says, it has a market-leading 29 percent share; Kautex has 23 percent; Ford's Visteon Automotive Systems, 21 percent; and Walbro, 18 percent. Plastic Omnium SA of France has a smaller but growing market share.
US acceptance of the tanks took off several years ago after plastics suppliers developed multilayer tanks of high-density polyethylene that prevented fumes from escaping, unlike earlier, single-layer tanks, and met toughening emissions standards.
Besides being impermeable, plastic tanks are also durable and light, and offer much greater design flexibility than steel.
For the new version of a GM rear-wheel-drive model, Solvay is providing 'a tank that's almost shaped like a butterfly,' to fit around the drive shaft, says Francois van der Wielen, engineering director for Solvay Automotive Inc. 'You couldn't do that with steel.'
And with Chrysler, Solvay is 'able to maximize the tank envelope by matching our CAD software with theirs,' says David Westgate, Solvay Automotive's chief executive.
While high-density polyethylene is more expensive weight-for-weight than steel, the two types of tanks cost about the same on a fully expensed basis - in part because dies for steel tank stampings are much more expensive than plastic tank molds, says Frank Fodale, supervisor of minivan platform fuel systems for Chrysler.
Plastic tanks weigh 20 percent to 30 percent less than comparable steel tanks. 'On a mid-sized car, that can be five to seven pounds (11.0kg to 15.4kg) of weight savings,' says Michael Shope, Walbro's chief financial officer.
The ability to integrate tanks into a complete modular system is increasingly proving to be essential, says Solvay's Westgate.
Besides the tank itself, such systems typically must include the fuel pump and sender, filler neck, evaporative-emissions canister and 'any plumbing in the rear of the vehicle,' GM's Yaccarino says. 'That's a minimum package.'
Some technological issues still plague plastic tanks, such as how the seepage of fuel into inner layers fouls the recyclability of tanks, according to Chrysler's Fodale.
Ian Morton contributed