As helpful as they are, there is no substitute for an element of human fine-tuning, or putting butts in seats.
General Motors’ human factors engineers who understand biomechanics, psychology, quantitative research and ergonomics, applied all these disciplines to help make the seats comfortable in the 2014 Chevrolet Impala.
Customers for each car segment want more or less support and rigidity in their car seats. What the car will be used for – such as commuting, city driving or track racing – helps engineers establish precise parameters of comfort. Finding the “sweet spot” for each vehicle doesn’t come easy.
For the new Impala, volunteer seat testers ranging from 5th percentile females (5 feet tall, 110 lbs.) to 95th percentile males (6 feet tall or taller, 223 lbs.) spent hundreds of hours and logged thousands of miles in prototypes of the redesigned flagship sedan to evaluate seat comfort.
Seat testers typically drive or ride in prototype vehicles for several 60-minute intervals at a time recording initial feedback after the first 10 minutes. At each 60-minute interval, they numerically rate every aspect of the seat: cushion, backrest, lumbar support, headrest and side bolsters.
But tester feedback is subjective and design changes are often subtle because seat designs evolve from past programs and reams of data collected with precision instruments.
“Developing comfortable seats is both an art and a science,” said Jill Green, GM seat comfort lab manager. “Knowing how to translate a physiological impression into tangible design elements is the art, and knowing how to execute the design is the science.”
Seat tester evaluations alone would have been insufficient to achieve such results. That’s where tools like Oscar come in hand. The mannequin-like tool made of steel, plastic and aluminum is assembled in 18 removable parts weighing up to 170 pounds. Early in the Impala’s development, Oscar helped determine the overall dimensional layout of the interior, allowing engineers to make the best use of space.
State-of-the-art digital pressure-mapping technology was used to scan the rear-end impressions of people of all shapes and sizes over the seat surface, creating a map with more than 4,600 data points. A laptop computer used the data to generate graphics illustrating how occupants sit in the seat statically or while driving.
The Impala’s front seats are heated and ventilated, and bolstered for greater support. The seat cushions are designed to provide a firm, premium feel. LS models feature cloth seats, while LT comes standard with cloth/vinyl seats. Sueded microfiber-trimmed seats are available on LT and LTZ models, which feature standard perforated leather seating. Standard on LT and LTZ models, rear-seat headrests fold to improve rear visibility when there are no back-seat passengers.
Car reviewers have noticed the attention paid to Impala’s seats.
“After hours in the driver seat, we found ourselves just as fresh as we were before we set out,” wrote Mark Takahashi, automotive editor, Edmunds.com. “The outboard rear seats have enough head- and legroom for the average adult male to remain comfortable for extended trips as well.”