BUICK VERANO'S REFINED RIDE STARTS WHERE THE RUBBER MEETS THE ROAD

October 13, 2014 by Buick

• Careful tuning of tire design and materials helps reduce noise, improve comfort

DETROIT – The refined ride quality and quiet cabin in the 2015 Buick Verano start closer to the ground than extensive insulation and a well-tuned chassis. Down where the rubber meets the road, engineers tuned and refined the Verano's tires for reduced noise and a comfortable ride.

'Far from being little more than a chunk of rubber, tires are a complex machines, made up of dozens of components, chemicals and compounds that must perform perfectly to deliver the traction, braking safety, fuel economy, tread life and road manners today's drivers expect,' said Jim Smith, editor of Tire Review magazine.

'The tweaking and tuning that goes on behind the scenes, the heavy lifting by auto and tire engineers working in unison, produces tires that quietly perform flawlessly in the background, and a car that delights owners.'

According to Chris Arabian, a tire development engineer within General Motors' Tire-Wheel Systems group, the process of selecting and refining a tire is a balancing act.

'For the Verano, we needed to ensure we provided ride comfort, while also balancing fuel economy and rolling resistance, and delivering an engaging driving experience.'

Arabian's team worked closely with tire manufacturer Continental Tire to develop two distinct tire packages for the Verano. The 17-inch P225/50R17 tire, standard on the base Verano, focuses on delivering low rolling resistance, which helps improve fuel economy. The 18-inch, P235/45R18 tire, which is standard on the Verano Turbo, was designed to provide crisp handling and a sportier feel.

Tire tuning isn't always a straightforward process – in fact, pursuing one attribute often conflicts with another. For instance, tires with low rolling resistance commonly use rubber compounds that don't lose much energy as they roll along the road. However, compounds that do the exact opposite also excel at reducing noise and soaking up bumps in the road.

But the conflict can be resolved by modifying other elements of the tire. For example:

◾Tuning certain peak frequencies generated by the tire can reduce the chance that vibrations are amplified throughout the entire car.

◾Adjusting the steel belt package, which includes selecting the materials used and the angle at which the two steel belts are aligned. These variables influence ride quality by changing the tire's ability to flex and absorb imperfections in the road.

◾Adding a subtread, a layer of rubber beneath the outer tread layer, also works wonders. 'It's a great way to isolate a tire,' says Arabian. 'Adding a few hundred grams of low hysteretic material in the subtread of each tire can deliver the same noise reduction as several kilograms of insulation within the car.'

◾Modifying the tire's tread pattern can combat the high-frequency airborne noise emitted when a tire rolls down the road. Adjustments can include revisions to the tread block's shape or the depth and angle of the fine cuts made within tread blocks, which are known as sipes.

◾Altering the tire's footprint can also reduce road noise. While a tire's fundamental footprint on the ground is square, engineers may tune the tire so that footprint's leading and trailing are rounded. This allows the tread block to ease into the pavement instead of all edges striking simultaneously.

'There are so many variables we can adjust in the tire's construction,' said Arabian. 'Ultimately, when we optimize a tire, it means we can potentially reduce some cost, complexity, or weight elsewhere within the vehicle and still deliver the targeted level of refinement.

Buick is an international modern luxury brand offering vehicles with sculpted designs, luxurious interiors and thoughtful personal technologies, along with responsive-yet-efficient performance. Buick is attracting new customers with its portfolio of award-winning luxury models in North America and China. Learn more about Buick cars and crossovers at www.buick.com, on Twitter @buick, on Pinterest or at www.facebook.com/buick

Photo credit: Buick
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