When auto writers talk about cars, they often mention vehicle “platforms.” It actually refers to a number of aspects of auto construction, and includes design and engineering along with the actual metal.

“The platform is the underpinnings of the car,” says Paul Hewitt, product manager, global Delta for General Motors of Canada.

“It’s the floor pan and suspension of the vehicle.”

In the past, most cars consisted of a heavy frame with the body bolted on top. This body-on-frame construction is still used for pickup trucks and some large SUVs, since it provides the brute strength needed for towing and hauling, but its heavy weight affects fuel economy.


Today, most vehicles are “unibody” construction, where the body itself provides the structural strength through its floor, roof, pillars and firewall.

By making alterations to the basic design — stretching the wheelbase, adjusting the suspension, or modifying the passenger cabin — automakers can use the same basic platform to produce several models, which may look nothing alike.

This reduces costs and also allows the companies to make more than one vehicle on the same assembly line.

“If your platforms are drastically different, you need very different tooling in the (auto plant) bodyshop to accommodate vehicles of different platforms,” Hewitt says.

“The closer a vehicle is dimensionally in terms of wheelbase length and width, the easier it is for the manufacturers.”

Like most automakers, General Motors uses each platform for several vehicles.

For example, the Chevrolet Orlando crossover uses the same basic underpinnings as the Cruze compact sedan and Volt electric car.

“They share a similar width,” Hewitt says.

“The Orlando has a longer wheelbase to accommodate the third row, but it isn’t just a Cruze with a different back end. Vehicles can be drastically different visually, but share some commonality in suspension and width.”

Designing a new vehicle platform from scratch can take years of development and testing, Hewitt says.

“Then you start looking at the variants needed around the world. What we’re seeing globally is that vehicles of all different body styles are being built off the same platform, which in economy of scale reduces the manufacturer’s cost.

“You build one platform to cover a wide variety of vehicles. The days are gone where one platform was one car.”

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