Tesla Model 3's Aero Innovations
 |
Special To The Auto Channel
From Ales Alajbegovic
Exa Corporation
27 April 2016; Tesla's public launch of its first "affordable" electric car has revealed a number of clever approaches to making it as streamlined as possible.
Tesla CEO, Elon Musk, has said his drag target for the Model 3 is an incredibly low 0.21 Cd, lower even than the 0.24 value for the Model S. That slipperiness will be crucial to achieve Musk's goal of a minimum 215-mile range in a car that must, by necessity, limit the size of its battery pack in order to meet the stated base price of $35,000, before incentives.
Tesla uses Exa's PowerFLOW digital simulation software in-house to design its cars. We don't see the process, but by analyzing the cars that Musk unveiled at the end of March, we can see where Tesla has innovated.
Model 3's multiple wheel designs, for example, all appear to be very aerodynamic. The differing turbine-blade styling not only comes across as fresh and appealing, but it also directs the flow of the air under the body of the car to reduce drag.
That's smart. Tesla could have used an active aero solution that closed the vanes on the wheels at speed, but they chose not to. In fact, it appears there are no active aero devices on the Model 3, which reduces the cost of making it.
Most noticeably, Tesla has removed the grille graphic from the Model S. An electric car has of course no need for cooling that high up, and the company had already reduced the presence of a grille significantly on the Model X and facelifted Model S.
Here only the shape remains. A more wedged front end, such as used by rear-engined Porsches, might well be more desirable aerodynamically, but Tesla could be using the grille shape with its rounded edges to control the air flow over the top or round the sides of the car.
The Model 3 also employs air curtains in the lower fender that exit ahead of the front tires to provide a drag-reducing air stream over the wheels, while helping the flow transition smoothly around the sides of the vehicle. The underbody is likely to be flat and smooth, ending with a rear diffuser to control the air coming from under the car.
Some predicted Tesla would use cameras instead of wing mirrors, but maybe the company is not confident of persuading regulators to switch to cameras by the time the car arrives at the end of next year. Instead it has thinned the mirror mounts to improve aerodynamic performance and has paid careful attention to reduce the drag of the mirror body.
The effects of all this will be seen by the drivers. Reducing the Model S drag figure from 0.32 to 0.24 increased range on a single charge by around 50 miles and this further reduction could free up another 10-20 miles.
The incredible launch buzz around the Model 3 has persuaded nearly 400,000 people to put down $1,000 deposits for the car. As that buzz reduces, the extra range created by careful attention to aerodynamics could be just enough to persuade more skeptical customers to make the switch to electric.
