Since the advent of hybrids and electric cars, debate has raged about their efficiency over a full lifecycle. Sure, they use less fuel when strapped to a government test rig, but do they create fewer CO2 emissions throughout their entire manufacture-to-recycle life? Mercedes handed an E350e to the German Technical Inspection Authority (TÜV Süd) to prove hybrid power is cleaner than gas in the long run.
The E350e absolutely blows a regular E-Class away on the testing rig, returning 2.1 l/100 km (112 mpg) on the New European Drive Cycle (NEDC). That's close to half the 3.9 l/100km (60 mpg) used by the base model E220d on the same test, while the hybrid's 49 g/km of CO2 is also significantly lower than the diesel can manage. The E350e can run on battery power for 33 km (21 mi) as well, which means it can run smoothly and silently through the city with no local emissions.
With a 65 kW (88 hp) electric motor hooked up to a miserly four-cylinder petrol engine, the car punches out a useful 210 kW (286 hp) of power and 550 Nm of torque. Unlike old hybrids – or current hybrids: we're looking at you, Prius – that means the E350e should also drive like a normal car, rather than a glacial science experiment.
But one of the biggest criticisms of hybrid cars has been the fact they aren't usually able to back up the claimed fuel efficiency figures in the real world. There's also the question of how much CO2 is emitted in the production of electricity used to charge the battery.
According to the lifecycle analysis conducted by TÜV, building, owning and recycling the new E350e emits around 44 percent less C02 than the outgoing E350 CGI, which offered similar performance to the new hybrid, but ran with a conventional petrol engine instead. The testing assumes the car has been charged using a conventional European plug, but also says using renewable energy to charge the battery could improve that figure to 63 percent over the course of 250,000 km (155,343 mi).
"The Plug-in Hybrid is a good example of how a transparent analysis of the entire life cycle is required to show and evaluate the environmental impact in its entirety," says Anke Kleinschmit, Head of Research and Chief Environmental Officer at Daimler. "With these analyses, we go way beyond the statutory requirements. They also enable us to prove that the naturally higher use of resources in production is more than compensated for by the significantly better ecological balance when driving, meaning that the overall Life Cycle Assessment is improved, too."
This isn't the first time Mercedes has published a lifecycle analysis of one of its cars. In 2015, it released a breakdown of how much CO2 the GLE350e four-wheel drive uses over its manufacture-to-recycle lifetime. That car emitted about 37 percent less CO2 using a normal European energy mix, with savings jumping to around 58 percent if the car is charged with renewable energy.