Jaguar Land Rover is introducing a new powertrain classification as it prepares for the rollout of electric cars.

Automakers have traditionally relied on engine displacement for powertrain classification. However, things become difficult when the powertrain consists of electric motors and batteries.

Starting with the 2018 Jaguar E-Pace, Jaguar Land Rover has decided to classify its powertrains with a letter defining the fuel source and a number defining the power, as measured in metric horsepower.

For example, a Jaguar E-Pace on display during the recent 2017 Frankfurt Motor Show had a “D180” badge on its tailgate. The “D” signifies that this is a diesel model and the “180” signifies that there’s 180 horsepower available. Under Jaguar Land Rover’s former classification, the E-Pace would have sported a 20d badge, where the “20” signifies the 2.0-liter engine displacement.

Gasoline-powered models will use a “P” to denote the fuel source, with the letter presumably signifying petroleum. For Jaguar Land Rover’s electric cars, we should see a letter “E” used. The first electric car will be the I-Pace due on sale in 2018.

Audi in August introduced its own new powertrain classification. It picked arbitrary numbers ranging from 30 to 70 to represent power, with values increasing by measures of five. For example, a “30” on the trunk or tailgate will mean there’s 109 to 129 hp available. If it’s a “70,” you’ve got 536 hp or more on tap. As for the classification of powertrain type, Audi uses TFSI, TDI and e-tron to define gasoline, diesel and electrified powertrains, respectively.