Cheryl Simpson, an employee at Ford's Van Dyke Transmission Plant, builds a six-speed transmission. Ford filed a patent for an 11-speed transmission.

You can never be too thin, too rich…or have too many gears, it seems.

Even as it moves ahead on a joint venture developing a 10-speed automatic transmission, Ford has been granted a patent for a new design that would use 11 gears.

That might come as a shock to older motorists who remember the long-running debate over the need to upgrade to four- or five-speed gearboxes. But carmakers are racing to add ever more gears to their transmissions as they struggle to meet tough new fuel economy and emissions standards.

Chrysler only a couple years ago became the first major maker to put a nine-speed into production with the Dodge Dart and Jeep Cherokee models. Problems with that transmission delayed the launch of the SUV and have been hurting the maker’s quality scores, however, underscoring some of the challenges manufacturers face.

Outlining three possible approaches, Ford said its gearbox “produces 11 forward speed ratios and one reverse speed ratio by selective engagement of three shift elements in various combinations.”

That’s significant in that manufacturers no longer use a single set of gears for each of the individual ratios in a transmission. They mix and match to come up with different combinations. As a result, some of the newer multi-gear boxes are smaller and lighter than the less advanced transmissions they replace.

Why so many gears? Internal combustion engines may operate across a broad RPM spectrum but they typically are most efficient when running in a narrow band. The goal is to shift gears to maintain optimum performance.

The challenge, however, is to do that smoothly and imperceptibly so as not to disturb customers. Some early seven-, eight- and nine-speed gearboxes have had problems with so-called hunting-and-seeking, constantly shifting to remain in the sweet spot, but creating an uncomfortable ride for passengers.

For decades, three, four and five-speed automatic transmissions dominated the auto industry, with manual gearboxes reserved either for those seeking maximum fuel economy or top performance. More than 80% of all new vehicles produced in model-year 1999 were equipped with so-called L4 transmissions, according to the EPA.

The push to six speeds and began got underway in earnest as the new millennium began, and accelerated as federal lawmakers approved tough new mileage standards for 2016 and then for 2025, with the Corporate Average Fuel Economy mandate set to reach 54.5 mpg a decade from now.

(VW creates a 10-speed DSG transmission. For more, Click Here.)

Six-speed transmissions are expected to account for about two-thirds of the industry this year, but unlike the four-speed, which dominated for nearly 20 years, changes are now expected to come quickly.

Seven- and eight-speed automatics are in increasingly common use, from mid-range to luxury models. New nine-speed transmissions are available in a number of vehicles, as well. And Ford has been working on a 10-speed with General Motors expected to debut within another year.

But the smaller of the two apparently thinks there are opportunities to go one higher. The challenge will be holding down costs while maintaining high quality and comfort standards, industry observers stress.

(Click Here for details about more gears equates to better fuel economy.)

There are other big changes in the transmission world.

Manual gearboxes continue to lose ground, partially due to a lack of training among your drivers, but also because of increased competition. Where sticks were long able to deliver both better mileage and performance, new automatics — such as the 8-speed added to the Chevrolet Corvette Stingray line in 2015 — are often faster, more fuel-efficient and less likely to suffer emissions spikes.

Manuals also face challenges from new electrically shifted double-clutch gearboxes that combine the best of manuals and automatics. Known variously by such acronyms as PDK and DCT, they are the fastest packages on such sports car models as the Porsche 911 and the new Ferrari 488.

(Buttons, dials, paddles: this isn’t your father’s transmission. Click Here to see more.)

Then there’s the CVT, or Continuously Variable Transmission, a system that essentially offers endless gear ratios to always keep an engine running in its sweet spot. But early CVTs faced reliability issues, as well as consumer complaints about the so-called “rubber band effect,” where the car seemed to lag behind the engine as it accelerated.

New CVTs have improved performance significantly and are widely used by makers such as Nissan. But some analysts warn that new versions of traditional step-gear automatics could reduce the advantage of CVTs.