Time was that the most gears you could get in an automatic transmission was three or four.

Then came five- and six-speed automatics, which are now pretty much the standard (along with increasingly prevalent continuously variable transmissions, or CVTs).

But the transmission wars have continued to escalate.

DON'T MISS: Auto Industry Doing Fine In Meeting Gas-Mileage Goals, It Turns Out (Aug 2014)

Today, seven-, eight-, and nine-speed automatics are offered in everything from large European luxury sedans to the Jeep Renegade subcompact SUV.

Now Autoguide has reported on a patent filing by Ford for an 11-speed automatic transmission, in three different variants with different combinations of gears, clutches, and brakes.

Ford patent documents for 11-speed automatic transmission

Ford patent documents for 11-speed automatic transmission

The application was apparently filed in October 2013; the U.S. Patent Office published the actual patent last week.

Ford has already confirmed plans to launch an all-new 10-speed automatic transmission in its aluminum F-150 pickup truck sometime next year.

ALSO SEE: Fuel-Efficient 9- And 10-Speed Auto Transmissions Coming From GM, Ford (Apr 2013)

Thus far, the new automatic has only been confirmed for the 2017 Ford F-150 Raptor high-performance model, but it is expected to spread widely across the sprawling F-150 lineup over time.

But the new transmission it may be envisioning could conceivably be used in front-wheel-drive cars with transverse engines, just as today's ZF-derived nine-speed automatic appears in a variety of cars from Fiat Chrysler and Jaguar Land Rover, among other makers.

ZF 9-speed automatic transmission for transverse engines

ZF 9-speed automatic transmission for transverse engines

A report last year credited multi-gear transmissions as one of the main technologies that have let automakers meet increasingly stringent corporate average fuel economy (CAFE) standards.

The advanced transmissions, along with direct injection, lightweighting, and downsized engines, have kept makers in compliance with the stiffer CAFE standards without having to electrify vehicles with hybrid-electric powertrains.

MORE: Pickup Truck Gas Mileage, 2015 And Beyond: 30 MPG Highway Is Next Hurdle (Feb 2014)

As fuel-economy rules continue to escalate, it will be interesting to see how many gears can be packed into an automatic transmission at a cost that makers are willing to pay.

At some point, the incremental gains will dwindle and a CVT would seem to make more sense.

Ford patent documents for 11-speed automatic transmission

Ford patent documents for 11-speed automatic transmission

This is especially true as new control software has allowed CVTs to mimic the behavior of conventional automatics, reducing the "CVT whine" that drivers dislike as engines run up to their most efficient speed and stay there, decoupling engine sound from road speed.

But clearly Ford feels that 11 gears are at least possible--despite statements by Stefan Sommer, CEO of ZF, that nine speeds are the "natural limit" for number of gears in an automatic.

So this may simply be Ford protecting reseach it's conducted, with no immediate plans for putting such a transmission into production.

Let's see what kind of fuel-efficiency boosts that 10-speed automatic provides first.


Follow GreenCarReports on Facebook, Twitter, and Google+.