The Ford ETX-1

Bob King, of General Electric Global Research, had built his first battery car in 1972. Working with a Volkswagen chassis, a DC motor and lead-acid batteries, he built an electric car with a real-life range of 50 miles (80km). Since his daily commute to work was just 20 miles (32km) he could make it there and back with charge to spare.

In 1977, King helped create the wedge-shaped GE100, a four-passenger electric vehicle built as a technology showcase for the company’s centennial anniversary. The following year GE revealed the Electric Test Vehicle-1 (ETV1) built in collaboration with Chrysler. GE provided the traction motor/drive and Chrysler donated the body – the US Government stumped up the development cash. The ETV1 was an impressive start but it was just a warm-up for an altogether more ambitious project.

In 1981, GE teamed up with Ford to work on an advanced electric vehicle powertrain that was subsequently presented to the US Department of Energy (DOE) as an unsolicited proposal. The concept used the best of both companies’ technology and was based on the idea of a motor and transmission concentric with the drive-wheel axis. Officials at the DOE were impressed by the concept. They reasoned that the combined motor/transaxle combination would be smaller and lighter than the DC motors that were ubiquitous in electric vehicles at the time.

Beginning in 1982, DOE initiated an aggressive research effort with universities, the private sector and federal agencies, to develop technology to reduce EV maintenance costs. Subsequently, a contract for the development of a proof of concept electric vehicle was awarded to Ford on 15 April 1982, as part of the Government’s Electric and Hybrid Vehicle Program (EHVP).

The ETX-1 vehicle used a very advanced AC drive system co-developed by Ford, General Electric, Exxon Research and Engineering and Lucas Chloride EV Systems. A tubular lead-acid battery provided 200V, which drove a 50bhp two-pole induction motor.

Ford selected its most fuel-efficient car as a donor vehicle for this new drivetrain: the Mercury LN-7, a curious two-door coupé, which was somewhat loosely based on the European Mark III front-drive Escort. It removed the asthmatic 1.6-litre CVH 4-cylinder petrol engine and replaced it with the integrated motor/transaxle, which contained a two-speed automatic transmission with the oil-cooled AC motor mounted concentrically with the drive-axle axis. The power electronics and control system fitted beneath the bonnet and the battery modules sat, in a stepped arrangement, in the boot and beneath the seats.

According to the DOE, the ETX-1 was the first electric vehicle to demonstrate a useful range in excess of 100 miles (160 km). A report on the project concluded:

In comparison to earlier electric vehicles, the ETX-1 demonstrates significant technological improvements such as a 50 per cent weight reduction, a 40 per cent reduction in size and a 25 per cent improvement in acceleration, without compromising efficiency. The ETX-1 program has demonstrated that EVs can effectively compete with conventional vehicles in certain market segments. The project validated the use of the integrated system design for effective use of resources in EV research and development.

The ETX-1 advanced electric powertrain programme was officially completed in August 1985. Tests performed under the programme verified that the vehicle met its targets for energy consumption, acceleration and what the DOE called ‘automotive-industry-acceptable driveability’, although, as it was an offspring of the fairly unremarkable Escort, no one was hailing the EXT-1 as a great driver’s car.

Encouraged by this success, the DOE had already placed a second contract in March 1985 for a second-generation, single-shaft, electric-propulsion system. However, the US Government had given up on the idea of convincing North Americans to forsake their gas-guzzlers in favour of EVs. The ETX-II project was for a small commercial van application. This was a shame as, by July 1988, Ford and GE had developed the AC drive system used in the ETX-1 into a very advanced powertrain indeed, using new UK-designed sodium-sulphur batteries.

The advanced AC electric drive system used a 70 bhp motor, courtesy of GE Motors, that was claimed to be 96 per cent efficient. The maximum torque output was 81 lb ft (110 Nm), which made it perfect for commercial applications. Fitted to a Ford Aerostar minivan, the ETX-II had a range of 100 miles (160 km) and a top speed of 60 mph (96 km/h).

The ETX II-Aerostar
The ETX II-Aerostar

Unlike the ETX-1 powertrain, which was designed to replace a front-wheel drive set up, the ETX-II was designed for rear-wheel drive applications. The major powertrain differences were:

  • The ETX-II incorporated an AC interior permanent magnet traction motor, as compared to the AC induction motor used in the ETX-I.
  • The motor/transaxle was arranged as a rigid rear-wheel drive axle, eliminating the need for the constant velocity joints that were needed for front-wheel drive.
  • The ETX-II powerplant was also designed for much heavier applications, where higher power and torque were required.
  • The ETX-II incorporated new gear ratios to satisfy the requirements for performance and energy efficiency.

Although the ETX-II powertrain had been developed with a small van in mind, had it been fitted to the ETX-1, it could have given that car the performance it so dearly needed.

Worse still, the oil fields of the Middle East were working again and no one felt the need to buy an electric vehicle. It was a bitter blow to Bob King. ‘I thought that, in five years, maybe EVs would be commercially viable,’ heremembered in 2010. ‘But once the price of gas settled at a dollar a gallon, there was no shortage of gasoline. The energy crisis was over, and everyone went back to consuming gas.’

King’s hard work wasn’t all for nothing, however. GE’s research into reducing emissions paved the way for New York’s first hybrid buses in 1996 and established the emissions requirements for a new generation of environmentally friendly public transportation.

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