Gauging Interest

A closer look at Lexus’s supercar-inspired speedometer

1/8/2014—Inspired by the design of the Lexus LFA digital gauge, the Lexus IS F SPORT meter is a graphical feat achieved through a successful combination of cutting edge technology and old-school mechanics. Consisting of an eight-inch thin film transistor liquid-crystal display (TFT-LCD) framed by a ring-shaped element mounted over the screen, it measures 4.7 inches in diameter and sits at the center of the monitor, with the digital elements of the gauge displayed at each side.

The motor-powered ring acts as the gauge’s outer rim and slides to the side when the driver uses the switch on the steering wheel to call up information such as mileage or music playlists.

“Installing a digital tachometer makes logical sense for high-performance models such as the LFA and IS F SPORT range,” explains Naoki Kobayashi, chief engineer at Lexus, “because the graphic hand of the electronic meter can track and display the engine’s capability to rev from idle to its 6,600 rpm red zone far more accurately than its analog counterpart.

But no one has tried to combine that with analog physical parts to build an instrument cluster with engineering excellence. You would be forgiven for assuming that the tachometer is nothing but digital, though, because it’s so well put together.” The benefits of opting for a digital gauge are notable. The graphics of the gauge change according to the vehicle’s mode.

For example, when the Sport/Sport S and Sport S+ modes are selected, the tachometer turns white and illuminates the rev gauge, a clever design nod to the gauge on the Lexus LFA. (Not coincidentally, the rev gauge itself has the same reading system as the LFA’s, with the spacing between gauge numbers slightly different—each gap between 0 and 5 is set narrower than those between 5 and 7, so the driver can visually recognize dynamic acceleration and feel more connected to the vehicle.)

It’s no secret the engineers went to great lengths fine-tuning the workings of the tachometer. The rim’s surface features complex hairline carvings to accentuate its metallic texture, while its interior wall is polished to mirror the graphics of the tachometer, an engineering treatment that allows the two-dimensional digital meter to appear almost three dimensional inside the rim.

“When it comes to meters nowadays, everyone has gone digital,” says Kobayashi with a smile. “That is handy because it has freed engineers from the burden of having to deal with physical objects, but it’s not interesting in terms of engineering.”

So what’s next? “I think our latest F SPORT meter has opened up a lot of possibilities for the development of the instrument cluster,” Kobayashi concludes. “In that sense, you could say that this is only the first of more interesting elements to come.”