A little before 7 a.m. in a tiny town in Nevada. A handful of vehicle developers from a German car manufacturer meet at the reception desk in the nameless hotel – far from home, the final phase of prototype testing is underway. It’s being upgraded – that means after checking out, it’s straight into the underground car park, where there are a few cloaked vehicles parked in a dark corner. The gigantic overcoats are fastened with locks around aprons and wheels to protect against prying eyes, so that no one photographs the top-secret prototypes, even at night. Once the mats have been removed by the development engineers, the inexperienced observer is hardly any the wiser. The vehicles – all medium-sized electric SUV models – are wrapped in wild foils to make them unrecognizable on the road. Interior camouflage mats also mutilate the cockpit beyond recognition when shopping or reloading.
A short speech, then after a “go” by radio it starts. The small convoy is secured at the front and rear by two production vehicles. It goes towards the Mojave Desert and then on through Death Valley past Las Vegas. The main concern today is the battery load of the electric models in high heat. “We stress the batteries so hard during testing that no customer does,” explains Andreas, who has known the electric crossover inside out for more than two years. But one test a day alone has long since ceased to exist. At the same time, today’s test trip is about dust, cooling air, aerodynamics and of course the air conditioning inside. Chassis and engine do not play a significant role on the packed test day.
A few thousand kilometers further in northern Spain, Mercedes engineers are on the road with the electric G-Class, which is finally set to celebrate its long-awaited premiere in 2024. The electric G-Class, which will probably already do without the EQG designation, started near Barcelona with camouflage foil protection. But the camouflage is actually superfluous, because the Elektro-G is clearly recognizable as such. The A-pillar is a bit rounder – but that’s about it. Electric through the terrain? The G-Class will hardly be the only one there; but many will measure themselves by it. The Stromer is ideally designed for rough off-road use. It starts with the lithium-ion batteries. They are integrated into the robust ladder frame made of steel up to 3.4 mm thick and it is precisely this that is subjected to tough testing in the field.
This not only makes the body significantly more torsion-resistant, it also ensures a low center of gravity. Even at extreme angles of incline, the G-Class stays firmly on the ground. In order to protect the batteries, which come from the group shelf and are also installed in the other electric Mercedes models, the developers have developed extra robust underbody covers made of an extremely resistant material. The prototype landed hard on rock and stone half a dozen times during the off-road climbing tour – completely unscathed. The developers are happy.
Porsche is not only testing the new electric Macan, but also its Cayenne, which is getting a major facelift because it will remain in the range as a combustion engine with electric support until the end of the decade. “We received feedback from customers that the Cayenne was too tight,” says chassis specialist Martin Werner. The struggle for comfort without diluting the Porsche DNA can be felt during the test drives. The wheel diameter of the 21-inch tires, which has increased by 30 millimeters to 790 millimeters, and the associated higher rubber flank also contribute to this. “The chassis was good up to now, but now our colleagues have upped the ante,” says series manager Stefan Fegg, “we got everything out of the MLB evo architecture.” The technicians also have a hand with the basic plug-in hybrid created. Less in the drive train, which has been spiced up with 6 kW / 8 PS to 346 kW / 470 PS and a maximum torque of 650 Nm, which is 50 Nm less than before. It gets exciting when you look at the power distribution of the two drive units.
But only some of the torture tests take place during the hundreds of thousands of test kilometers. A large part of the testing is now carried out on test benches. The battery and drive technology is no exception. At General Motors, the threads come together in the battery laboratory in Warren, Michigan. “Here in Warren, the batteries are tested long before they get into our electric cars,” explains Eric Boor, Senior Operations Manager Battery Systems Lab. “We test seven days a week, 24 hours a day, 365 days a year. We disassemble the batteries and cells ourselves, put them back together, analyze and test – test again and again. That’s why we test the modules for three years before they find their way into one of our models.” The batteries are not only scrutinized in the laboratory, but also repeatedly shipped to the prototypes, which are sold under each of the GM brands gondolas in three-digit numbers all over the world to collect test kilometers. The new flagship Cadillac Lyriq, with its 104 kWh battery pack, delivers 620 watts per liter of battery power. “In the long term, 850 or even up to 1,100 watts are possible,” says Tim Grewe, Director of Electrification at General Motors, “then the batteries will be smaller and of course lighter. That is also important for the costs.”
The Rolls-Royce Specter, the Bavarian Brits’ first electric model, is also in its final testing phase. At the end of the third test phase, the electric luxury coupé had covered almost two million kilometers. But before the market launch, the torture continues; currently parallel in Germany, northern Sweden, the USA and South Africa. In South Africa, the Specter is traveling to two locations; in the northern Cape region of Augrabies and in the Franschhoek vineyards. The different climate zones offer the best opportunities for summer tests. On hot days, temperatures can exceed 50 degrees Celsius, while the southern region offers a wide variety of surfaces and terrain, including winding country roads full of gravel, dust and dirt. “The reason for our extraordinary and relentless global testing process is simple: there has never been an automobile quite like the Spectre. As the first all-electric Rolls-Royce, the Specter not only represents a new paradigm in our technology, but the entire future direction of our brand,” explains Dr. Mihiar Ayoubi, technical director at Rolls-Royce.
By the time testing of the first electric Rolls-Royce is complete and the first vehicles roll out to customers in late 2023, the Specter will have undergone extensive testing designed to simulate nearly 400 years of normal use in some of the most extreme conditions on earth . As with many other models, the tests began in winter 2021 in a special test facility in Arjeplog / Sweden near the Arctic Circle. In temperatures of minus 40 degrees Celsius, engineers refined every aspect of the Spectre’s performance and handling in snow and ice, as well as the effects of sustained extreme cold on the vehicle’s batteries and other electronic systems. When it comes to electric drives, there is still a little more work to be done.
