Improving EV efficiency through the use of a continuously variable transmission

"There's a growing consensus among powertrain experts that EVs need to evolve multi-speed transmissions if

they are to realize their full potential" This is the tagline from a recent article in "Transmission Technology

International" which reports that industry has recognised the need for a transmission within an electric vehicle.

This project is to investigate the overall efficiency gains that can be achieved by including a variable

transmission into an electric vehicle instead of the normal single speed transmission. A variable speed

transmission would overcome drawbacks such as energy loss during shifting and passenger discomfort. This will

allow significant improvements in energy efficiency to be made as well as potentially allowing the electric

motor to be downsized. Initial modelling studies have indicated that improvements of 16% could be achieved.

The improvements will be quantified during the project to prove the increase in EV range The project will utilise

a Mazaro Variator transmission fitted to an electric Nissan Cabstar. The Mazaro transmission has a novel

approach, which produces a very high mechanical efficiency at all speed ratios and so is ideal for this project.