Driverless cars are giving engineers a fuel economy headache

New York

JUDGING from General Motors Co's test cars and Elon Musk's predictions, the world is headed toward a future that's both driverless and all-electric. In reality, autonomy and battery power could end up being at odds.

That's because self-driving technology is a huge power drain. Some of today's prototypes for fully autonomous systems consume two to four kilowatts of electricity - the equivalent of having 50 to 100 laptops continuously running in the trunk, according to BorgWarner Inc.

The supplier of vehicle propulsion systems expects the first autonomous cars - likely robotaxis that are constantly on the road - will be too energy-hungry to run on battery power alone.

In an industry where the number of LEDs in a brake light are scrutinised for their impact on gas mileage, processing data from laser, radar and camera sensors will be an enormous challenge - not just for coders working on machine learning, but for engineers trying to power v…