According to Halonen, it’s a unique time for lightweighting. In the past few years, the topic has become front of mind in the automotive industry.
Each manufacturer is trying to figure out where to save weight based on each vehicles’ mission and price point. Halonen cites one interesting example. A GM pickup will hit showrooms this Fall with a carbon fiber composite bed. The material cuts about 65 pounds from the weight of the vehicle.
But he’s quick to correct a misperception. Lightweighting is a big deal … even though vehicles aren’t always getting lighter. Instead, producers are looking to cut weight so they can add more features. Better seats might come at the expense of cutting a few pounds from the frame.
As far as brakes go, lightweighting is still more theoretical than actual. Given the importance of brakes, some reluctance to change makes sense.
There’s also the problem of friction. Discs are iron, so brake pads are engineered to work with iron as a friction couple. If discs are made from aluminum or a carbon composite, then a whole new generation of brake pads has to follow. And making sure that repair shops — or consumers changing brakes at home — match the right pad to the right disc becomes imperative from a safety standpoint.
From Halonen’s perspective, the reward is worth the risk. “Motivated suppliers are always looking for something new because they can command a higher margin and have fewer competitors,” he says. He points out Hella’s bi-metal brake discs, which blend iron and aluminum and weigh up to 20% less than typical iron discs. These discs don’t require any reengineering of brake pads. The wear surface is still iron. This is a low risk change.
Halonen points to electrified vehicles as a possible catalyst for change in the brake industry. Most of the work of slowing down a hybrid or full electric vehicle is done by the electric motor, referred as regenerative or “regen” braking. In this case, are heavy iron discs really necessary? “A change in powertrain, from full IC engine to some level of electrification, will enable lightweight brakes,” Halonen says. “Electrification, hand-in-hand with lightweight brakes, makes complete sense.”
Cutting the weight of the four corners of a car creates a cascade. Control arms can be less robust. “Reduce the weight on the wheel-end and pretty soon the suspension parts can be lower weight, a mass decoupling effect,” Halonen says. The impact spreads through the entire vehicle.
“Change will happen through conversation. People need to get comfortable with the idea,” Halonen says. “You’ve got to start the conversation.”
Earlier in The Brake Report: When Will There Be a Focus on Lightweight Brakes?