Following a heads-up given by CEO Elon Musk last week on Twitter, the company has now shared some details of a new upgrade it will be making available for its electric sports coupe sometime in 2015. For a yet-to-be-disclosed price, owners can opt to have their cars upgraded with a 70-kWh battery, some aerodynamically-optimized body bits and low-rolling resistance tires. Together, the enhancements should offer a 40-50 percent range improvement and give Roadsters a 400-mile range under certain conditions. Originally, it came with a 56-kWh unit and was rated for 245 miles on a charge.
Tesla tells us that "this is a retrofit package currently in its prototype phase", and so it still isn't clear whether the changes will allow Roadsters to be compatible with the Supercharger network, or whether the body kit will affect the outward appearance. We do know that this automotive augmentation does not also apply to the Model S, though it does give hope that those cars will also be on the receiving end of similar upgrades in the future.
The California company plans to put its 3.0 package to the test sometime early in the new year, with a road trip from San Francisco to Los Angeles. Interestingly, it says that this will not be the last time it offers improvements for its original model. You can get more details on the update below.
The Roadster 3.0 package applies what we've learned in Model S to Roadster. No new Model S battery pack or major range upgrade is expected in the near term.
Battery technology has continued a steady improvement in recent years, as has our experience in optimizing total vehicle efficiency through Model S development. We have long been excited to apply our learning back to our first vehicle, and are thrilled to do just that with the prototype Roadster 3.0 package. It consists of three main improvement areas.
The original Roadster battery was the very first lithium ion battery put into production in any vehicle. It was state of the art in 2008, but cell technology has improved substantially since then. We have identified a new cell that has 31% more energy than the original Roadster cell. Using this new cell we have created a battery pack that delivers roughly 70kWh in the same package as the original battery.
The original Roadster had a drag coefficient (Cd) of 0.36. Using modern computational methods we expect to make a 15% improvement, dropping the total Cd down to 0.31 with a retrofit aero kit.
3. Rolling Resistance
The original Roadster tires have a rolling resistance coefficient (Crr) of 11.0 kg/ton. New tires that we will use on the Roadster 3.0 have a Crr of roughly 8.9 kg/ton, about a 20% improvement. We are also making improvements in the wheel bearings and residual brake drag that further reduce overall rolling resistance of the car.
Combining all of these improvements we can achieve a predicted 40-50% improvement on range between the original Roadster and Roadster 3.0. There is a set of speeds and driving conditions where we can confidently drive the Roadster 3.0 over 400 miles. We will be demonstrating this in the real world during a non-stop drive from San Francisco to Los Angeles in the early weeks of 2015.
We are confident that this will not be the last update the Roadster will receive in the many years to come.