Ford is revamping its automatic transmission range and by 2008 more than half in North America will be new.

The company said this week that it is working on new automatic transmission architectures – including five-speeds, six-speeds and continuously variable transmissions – that have a wider ratio span between the highest and lowest gear ratios, making better use of engine power and helping to improve fuel efficiency.

At the same time, Ford is working to improve virtually all of its existing transmissions. The company, as recently announced, is also working together with General Motors to develop a high-volume, front-wheel-drive six-speed automatic transmission with an estimated 4% to 8% improvement in fuel economy over four-speed automatics.

Ford plans introduce a variety of new transmissions within the next five years, including the new TorqShift five-speed automatic transmission, set to go on sale in F-Series Super Duty trucks, a new continuously variable transmission (CVT) and new front-wheel-drive and rear-wheel-drive six-speed automatic transmissions.

These new transmissions will offer significant fuel economy benefits, as well as smoother operation and performance feel, for greater customer satisfaction.

In addition, numerous efficiency improvements – including enhanced torque converter lock-up, new electronic control systems and reduced parasitic losses – will be applied to all existing Ford transmissions to maximise the amount of engine power delivered to the vehicle and to improve their shift quality and durability.

The ratio span of an automatic transmission is calculated by dividing the highest forward gear ratio (used for launch) by the top gear ratio (used for highway cruising). Increasing the gear ratio of first gear improves a vehicle’s launch acceleration. Reducing the top gear ratio lowers engine speed during highway driving, which improves fuel economy.

The ratio between the highest and lowest gears also is important for overall vehicle performance. Vehicles with four-speed transmissions typically have a relatively narrow ratio span, between 3.5 and 4.0, and must carefully balance launch performance and highway fuel economy.

“Increasing the overall ratio span can be a ‘win-win’ situation, allowing both performance and fuel economy improvement,” said Ford automatic transmissions chief engineer Phil Yuhasz. “We are developing our transmission designs to improve this ratio span throughout our full range of products.”

Ford’s new family of continuously variable transmissions, to be offered first in the Freestyle and Five Hundred vehicles beginning in 2004, provide a very wide (6.0) overall ratio span.

Starting in the middle of the decade, Ford’s trucks, SUVs and front- and rear-drive passenger cars also will be getting increased ratio span (6.0) with a new family of six-speed automatic transmissions.

The new six-speed transmission repackages gearing and other components in a very efficient layout that enabled engineers to squeeze six forward speeds into approximately the same size housing.

The new design, with more powerful electronic controls, also eliminates some of the bands and clutches that formerly would have been needed, saving both weight and complexity.

“While new architectures offer the opportunity to increase ratio span, we are also working to continuously improve the fuel efficiency of our existing automatic transmissions and drivelines,” Yuhasz said. “Advancements in friction materials, torque-converter dampers, fluids and control strategies will contribute to overall improvements in fuel economy.”

Ford’s new TorqShift is a newly designed five-speed automatic transmission, which will be available in the US early in the 2003 calendar year on mid-2003 model year F-Series Super Duty pickups and Excursion SUV models equipped with the new six litre Power Stroke diesel engine. This transmission will replace the four-speed automatic currently offered in those vehicles.

A variant is also now on offer in Europe, enabling Ford to offer automatic versions of its most powerful diesel Mondeo.

The new five-speed automatic features improved gear ratios, higher capacity pumps for better cooling, robust components and simplified shift controls. These features contribute to fuel economy improvements, reliability, smooth shifts and quieter operation.

A new hill-descend feature will improve driver confidence, particularly while towing. The transmission controller is able to recognise when the vehicle is going downhill, and if the driver taps on the brake, it automatically downshifts to help slow the vehicle. Further braking by the driver prompts another downshift if needed. On uphill towing, transmission shift points automatically adjust to allow the engine to remain in its maximum power zone.

Super Duty and the Excursion benefit from an increased overall ratio span with the new high-torque capacity five-speed automatic. This new transmission design also will allow lower engine idle and torque converter lockup speeds for additional fuel economy benefits.

In conjunction with ZF Industries of Germany, Ford will introduce its new family of Ecotronic continuously variable transmissions (CVTs) in the US in 2004.

The first vehicles in the US to have the new CVTs will be the Freestyle “crossover” vehicle and Five Hundred sedan, both of which will be built at the Chicago Assembly Plant beginning in 2004. In Europe, this new CVT design will debut in the 2003 calendar year but Ford is not saying in which model.

CVTs allow infinite variability between the highest and lowest ratios, with no discrete steps or shifts like on a traditional step-gear automatic transmission. This allows the engine to operate at its most efficient speed more frequently and further improves fuel economy. The Ecotronic CVT family is expected to improve fuel economy by up to 8% to 10% over a traditional four-speed automatic transmission.

Continuously variable transmissions are best suited for small to mid-sized, front-wheel-drive vehicles with engines of three litres and less in displacement.

“While this fundamental technology is not new, we do expect to lead the industry in volume of CVT-equipped vehicles, our design is more advanced than previous CVT designs,” said Ford engineer Craig Renneker.

The Ecotronic is considered a “second generation” CVT design with advanced electronic controls and an integrated computer control module.

The new continuously variable transmission will be built at ZF Industries Batavia Transmission Plant near Cincinnati, Ohio. Production is to start next year for European vehicles and in 2004 for North American products.

Ford will introduce an all-new rear-wheel-drive family of six-speed automatic transmissions beginning in the 2005 calendar year. The new transmissions, made in multiple variants for both cars and trucks, will provide fuel economy improvements in the range of 6% to 8%.

These transmissions use a very efficient architecture with reduced part complexity, low parasitic losses with comparable weight to many four-speed automatics. This transmission will also have the ability to automatically shift into neutral during extended idle conditions, to reduce drag on the engine. When the driver presses the accelerator to launch, the transmission will re-engage smoothly and automatically.
Sophisticated electronic control of the new transmission will offer several new features, including shift points that better adjust to specific driving conditions, and grade braking similar to that on the new TorqShift.

Ford and General Motors will also work together to develop a high-volume, front-wheel-drive six-speed automatic transmission with improved fuel economy over today’s transmissions.

Final agreement on the deal expected this winter. Both companies have been working independently on their own front-wheel-drive six-speed transmission programmes.

The new transmission will offer an estimated 4% to 8% improvement in fuel economy over traditional four-speed automatic transmissions available in today’s front-wheel-drive cars.

Under the memorandum, Ford and GM agreed to share a common design, engineering and testing of the new transmission; jointly work with suppliers to develop and purchase components; and assemble their own transmissions at their respective manufacturing plants.

The new six-speed would be available beginning in mid- to late decade on front-wheel-drive cars and sport-utility vehicles with mid- to large-displacement engines.

Only the base transmission design will be common. Each company will have powertrains that are distinct in feel and performance, since the transmissions will be mated to different engines, and the respective vehicle programs will have unique performance dynamics and calibration. Each company is responsible for integrating the transmission into its own vehicles.

The transmissions will share significant common technology and components. The design being pursued is a new architecture that will have optimal steps between gears and a wider gear ratio span to improve fuel economy. Featuring a compact design, the new six-speed will be capable of higher torque capacity when compared to most existing front-wheel-drive transmissions such as four-speed automatics and CVTs.