Premcar turns 30 in 2026. To celebrate, we’re sharing some of our carmaking knowledge. This time, it’s about predictable linearity.
Ernest Hemingway wrote a memorable quote in his novel ‘The Sun Also Rises.’
“How did you go Bankrupt? Bill asked.
“Two ways,” Mike said. “Gradually and then suddenly.”
The expression “gradually, then suddenly” has made its way into many areas of life.
But it has no place in new-car engineering and development.
The problem with “gradually, then suddenly” is you can’t predict what happens next.
This inability to predict makes rollercoasters, gambling and blind dates exciting.
But if you apply it to carmaking, it’s the uranium bullet that sparks everything from dissatisfaction to disaster.
It’s why automakers create driving experiences underpinned by a critical characteristic:
Predictable linearity.
If you plot two variables on an X-Y graph and then connect the dots, the dots should make a straight line.
A good example is steering feel, or how steering wheel torque builds up in the driver’s hands as more steering angle is applied.
When driving around a bend, as the driver turns the wheel, the feeling of resistance should follow a linear path, not a feeling of initial lightness and then sudden increased resistance, or vice-versa.
That feeling of increased steering weight should match with the suspension’s camber gain as the loading increases on the side of the car facing the outside of the corner.
And during cornering, the lateral acceleration drivers feel should be equally linear and predictable.
Because if these elements aren’t linear and predictable, the driver will act to counter these forces.
In this case, they will start making steering adjustments. Their eyes will start darting towards different points of the road closer to the car, which in turns will trigger more steering adjustments.
All of this creates uncertainty and unnecessary driver reactions, contributing to fatigue.
For these reasons and so many more, it’s why we design and engineer predictable linearity into steering, suspension and other vehicle systems.
Predictable linearity helps create the driving experience that owners and journalists often describe as “good steering” and “great feel”, and feedback like “After driving for two hours I got out of the car feeling fresh.”
Linear relationships are predictable, and predictable vehicle operations give drivers the experiences and feelings they want.
By the way, predictable linearity also applies to most other parts of the new-car industry, including vehicle distribution, retail sales, service bookings and other business operations.
Don’t go for broke by being gradual and then sudden.
Choose predictable linearity.
Bernie Quinn, CEO of Premcar
About Premcar:
Premcar Pty Ltd is a leading Australian vehicle engineering business that specialises in the automotive, defence and aerospace industries. For 30 years, global car-makers have made Premcar their go-to partner for the complete design, engineering and manufacture of niche-model new cars, full-scale new-vehicle development programs, and electric vehicle (EV) conversions and manufacturing. Premcar’s body of work is extensive. It is the name behind more than 213,000 new cars and 55,000 new-vehicle engines. The company has delivered technical advancements and sales success for major car brands from Europe, the USA, Japan, China and Australia. Visit premcar.au.
