F1's changes
Weight
The new engines, extra electrical power and larger batteries mean cars are significantly heavier - a minimum of 691kg, rather than 642kg. It takes more energy to stop that on the brakes.
Front wing and nose
The front wing is 150mm narrower and the tip of the nose is lowered to 185mm, to try to improve safety in collisions.
Exhaust
In the past, teams directed exhaust gases on to the rear diffuser to improve downforce. Now a single exhaust pipe has fixed dimensions.
Engine
The change from 2.4-litre V8s to 1.6-litre V6 turbos produces 600bhp with an rpm limit of 15,000 compared to 18,000.
Fuel
The teams are allowed only 100kg of fuel as opposed to around 160kg in 2013. The rate at which they can use the fuel has gone down to 100kg an hour from around 170kg an hour.