What's Your Sine?

Years ago, I was working at the office when I felt I was coming down with something. By the time I decided to leave, I had a throbbing headache and probably a fever. It was an uncomfortable drive home but it also gave me great insight into how to evaluate the way a car rides.

Every time my head moved, I felt the throbbing increase. And I became acutely aware of how my head was rising and falling as I drove over every heave and dip in the pavement. If it rose and came back down smoothly it didn’t bother me much. But if my head moved abruptly or jiggled, the pain came in waves and left my ears ringing.

That’s when it occurred to me that you could illustrate a car’s movement driving down the road using a sine wave to describe the motion. A nice, soft, undulating sine wave is comfortable for the vast majority of people. A jagged sine wave is not.

Up through the 1970s, the traditional American sedan would produce a soft, undulating sine wave as it drove down the highway. It was called the “boulevard ride” and most car buyers loved the way it felt. But that comfortable ride was the result of soft springs, a not-so-rigid frame and seats with a lot of give. Unfortunately, it also was the antithesis of what automotive aficionados wanted in their cars.

The enthusiast press excoriated the boulevard ride and the cars that produced it. “Barge-mobiles” they were called derisively, with unacceptable “mushy rides.” And while it was true that American sedans did not handle well (or steer or brake well, for that matter), they sure were comfortable.

But the damage was done. The new enthusiast-driven ideal favored cars with stiff suspensions and firm seats, producing the coveted “European-style handling.” Ever since then we’ve had cars that let you feel the road. But you know what? I don’t want to feel the road when it means driving over broken pavement, potholes or impact strips.

The good news is today’s technology produces the best of both worlds. Adaptive dampers, with either adjustable shock valves or magneto-rheological technology, can provide a boulevard ride for straight-line cruising, or firm up to provide good cornering the instant you turn the steering wheel.

For example, one of the most impressive aspects of the ’14 Corvette Stingray is how smooth it rides, yet how precisely it corners. While the Corvette, with its MR shocks, doesn’t exactly offer a boulevard ride, it is hands down the most comfortable-riding high-performance sports car I have ever driven.

Even hardcore car buffs can appreciate a comfortable ride. Everyday motorists, who just want to get from point A to point B as comfortably as possible, will appreciate it even more.

There’s an opportunity for some automaker to revive the boulevard ride as a core characteristic of its brand. The public would be intrigued with invitations to take test drives of the cars that offer “the most comfortable ride you can buy.” And, as any dealer will tell you, getting car buyers to come in and take a test drive is a sure-fire way to close a sale. It could become a key selling point.

So I invite all of you in Product Development Land to pay close attention to the way your car rides. You won’t even need to run a fever to do the evaluation. All you’ll need to do is answer the question, “what’s your sine?”

John McElroy is editorial director of Blue Sky Productions and producer of the “Autoline” PBS television show and “Autoline Daily,” the online video newscast.