Transmission specialist Antonov reports that exhaustive testing of an electric vehicle equipped with the firm's multi-speed transmission over eight different drive cycles has proven that its multi-speed unit delivers approximately a 10-percent improvement in electric motor efficiency compared to a single-speed solution.
Antonov's business development manager, David Paul, says the transmission firm's analysis, shows that with a single speed gearbox, there is significant variation in drive-cycle efficiency, whereas a multi-speed unit tends to be more consistent. Additionally, Paul claims:
The UK's Technology Strategy Board asked Antonov to present detailed findings at the Cenex Low Carbon Vehicle Event 2011 at the Rockingham Motor Speedway in the UK, so keep your eyes peeled for more info on this potential plug-in breakthrough.Inevitably, there is a compromise with a single speed gearbox particularly in terms of low speed acceleration, hill climbing and high speed cruising. The 10 percent step change improvement in efficiency can be achieved with just two ratios, but technical compromises remain in other areas. Three or more ratios are better, delivering additional improvements in performance and refinement as well as efficiency, with each additional ratio providing small incremental gains in cycle efficiency.