Search Copying and distributing are prohibited without permission of the publisher
Email a friend
  • To include more than one recipient, please separate each email address with a semi-colon ';', to a maximum of 5

  • By submitting this article to a friend we reserve the right to contact them regarding AMM subscriptions. Please ensure you have their consent before giving us their details.

The consumer has spoken . . . curbweight is critical


Remember the old ad slogan, "Where's the beef?" The question of tomorrow in a more health-conscious environment might well be, "How much fat can you cut?"

Automakers will continue to tinker with different materials to slim down vehicle weight in an attempt to boost fuel economy, some analysts said.

"Weight is one of the biggest areas to be addressed. Everybody's vehicles need to go on a diet," said Jeffrey Jowett, manager of North American powertrain forecasts at CSM Worldwide Inc., Northville, Mich. That's especially true in the face of stricter fuel economy standards and consumers concerned about fuel economy.

That means more aluminum engine blocks and cylinder heads and even more magnesium cam covers. While composites remain expensive, automakers likely will use more of them—especially in body panels as suppliers get up to speed and volumes increase, bringing costs down, he said.

But in some respects, the more things change the more they stay the same. "You are going to have more electric powertrains, which means additional motors and batteries," Jowett said. "But I don't see the internal combustion engine going away for a while."

Automakers are doing anything and everything to get an extra half mile per gallon, according to Richard A. Schultz, project consultant at Ducker Worldwide LLC, Troy, Mich. "If you would have told the industry they had to do this a few years ago, they would have said, 'Oh, we can't.' But the consumer has spoken."

Switching from the body-on-frame design of a traditional truck or sport utility vehicle (SUV) to the unibody design of a car or crossover vehicle can shed as much as 800 pounds, lowering fleet curb weight by as much as 300 pounds, he said.

And the "watershed" moment likely will also see at least 95 percent of engine cylinder heads and 65 percent of engine blocks made from aluminum within the next year, he said. But it's not all roses for aluminum. Engine exhaust intake manifolds, 35 to 40 percent of which are made from aluminum currently, could see inroads from magnesium and plastics. But most are moving toward reinforced nylon, and alternative materials could make gains on engine covers as well. "All this is being worked on, and it's hot on everyone's plate because of fuel prices," Schultz said.

Like others in the industry, he said there has been an interest in a more-magnesium-intensive engine. But with the price of magnesium where it is, "it's not ready for prime time," he said. "(But) down the road, I think it will be a way to lightweight the internal combustion engine."

That's especially true because automakers need to offset weight elsewhere in hybrids to account for the increased weight of batteries. The battery on GM's first electric car weighed a whopping 900 pounds, he said, and even the Toyota Prius is not a lightweight car.

"The powertrain weighs more in the Prius than it would if it were just a conventional engine because the battery weighs so much, so you have to take weight out of the rest of the vehicle," Schultz said.

In the Prius, that means a small aluminum engine, an aluminum hood and an aluminum deck lid. The hybrid versions of the GMC Yukon and Chevrolet Tahoe SUVs also use aluminum hoods, tailgates and other parts to make up for the increased weight of the battery, he said.

But Schultz doesn't think the demise of the internal combustion engine is at hand. By 2014, only about 900,000 of the roughly 16 million vehicles produced in North America will be hybrids, he said. In the meantime, automakers will push to optimize the internal combustion engine with turbo charging, friction reduction, cylinder deactivation and other methods largely unrelated to material composition.

"They are going to keep perfecting the internal combustion engine because the majority of the vehicles in my lifetime are going to be internal combustion, either diesel or gasoline—not electric," Schultz said.

Kim Korth, president of IRN Inc., Grand Rapids, Mich., agreed that for the short term, anyway, the combustion engine will still rule the road. "I really don't think we'll be off the combustion engine any time soon. What we're seeing is more conversions to a combination of power sources. But I believe we'll see some breakthroughs on how automobiles will be propelled over the next four or five years. It's a fast-moving industry."

Brian Dunn, Montreal, contributed to this story.


Have your say
  • All comments are subject to editorial review.
    All fields are compulsory.