What is the Tesla Roadster?
From as early as 2015, Tesla CEO Elon Musk has been hinting at a new Tesla Roadster to replace the company’s first-ever vehicle. The original roadster was a Lotus Elise retrofit with batteries and motors rather than an engine. It was Tesla’s first car, and they learned a lot from it.
For example, the battery management system that was developed for the Roadster back in 2008 to prevent it from overheating and catching fire is not too dissimilar to the BMS found in modern day Tesla vehicles.
Given that the Roadster is now quite outdated, Musk decided it was time for a new one. Tesla has been working on the original roadster occasionally, for example giving it an aero kit in 2014 which reduced its drag coefficient down from 0.36 to 0.31.
The new Roadster has some killer specs. As it so happens, that’s exactly its purpose. The Roadster’s slogan on Tesla’s website says just that:
“The quickest car in the world, with record-setting acceleration, range and performance.”
During the launch event, Musk stated his intentions with the Roadster:
“The point of doing this is to give a hardcore smackdown to gasoline cars,”Elon Musk, Tesla Semi Launch Event 2017
“Driving a gasoline sports car is going to feel like a steam engine with a side of quiche.”Elon Musk, Tesla Semi Launch Event 2017
It’s not just rhetoric either, the figures that Tesla claims to be achieving with the prototypes fully justify these claims.
Those specs really capture the purpose of this car. It’s to show that ICE cars are completely obsolete, and that they are just collectibles. People will drive them for fun, and that’s fine, but Tesla is trying to make a car which is even more fun that doesn’t run on fossil fuels.
When will the new Roadster be produced?
When it was announced at the end of the Tesla Semi launch event in November 2017, Musk set out a target release date of 2020. Potential owners could reserve the base model for a hefty deposit of $50,000, or 25% of the $200,000 price tag of the Roadster.
Now it’s 2020, it has become apparent that the Roadster is not coming this year, partly due to the Coronavirus outbreak, partly due to other internal delays.
Moreover, the hypercar is not high on the list of Tesla’s priority list at the moment. Recently, Musk went on the Joe Rogan podcast (again), and, when quizzed about the Roadster, he said the following.
“Roadster is kind of like dessert, we gotta get the meat and potatoes and greens and stuff.”Elon Musk, Joe Rogan Podcast 2020
There are several things that Tesla aims to achieve before moving on to the Roadster, says Musk.
- Ramp up Model Y production
- Expanding Tesla Gigafactory Shanghai
- Build Gigafactory Berlin and start production
- Get the Tesla Semi to production
- Get the Cybertruck to production
Yes, that’s quite a list of monumental tasks. However, at Tesla’s pace of innovation, they’ll most likely get all of that polished off within the next few years.
Based on this information, we can predict that the new Roadster will be ready to start production in 2022 or 2023. It really is dessert.
Despite this unfortunate news for prospective owners, Musk made sure to reassure them that it will be worth the wait.
“Everyone who has been waiting, they won’t be sorry.”
How does the base model accelerate so quickly?
According to Musk, the 1.9 second 0-60 mph time is just the base model, which lacks the futuristic rocket technology of the founders edition.
There are several key technological improvements that will help it to accelerate so rapidly.
As you may know, the powertrain of an automobile comprises the main components that generate power and deliver that power to the road. Some parts of the powertrain include the transmission, driveshaft and motors.
To get such mind bogglingly quick acceleration, Tesla had to make something dramatically better than their current offerings. Beating the P100D is no easy feat, the saloon can polish off the 0-60 mph time in just 2.3 seconds. Getting down to 1.9 seconds sounds like a small reduction, but at these speeds, that’s an enormous increase in performance.
In order to pull it off, Tesla will be using the upcoming Plaid Powertrain. Plaid is a reference to Spaceballs, where Plaid is the only thing faster than ludicrous.
The new powertrain is likely to be used first in the Model S, creating a variant of it that is fully performance-oriented. This is set to be released later this year.
Total Battery Capacity /kW
Model S P100D
Model 3 Performance
Porsche Taycan Turbo
Porsche Taycan Turbo S
Tesla Roadster 2.0
Tesla Model S Plaid
The specs above demonstrate that the plaid powertrain means business. The motors in the Roadster are estimated to be almost twice as powerful as those in the Porsche Taycan Turbo, or for that matter, the Model S P100D.
Furthermore, the battery capacity of the Roadster is twice that of the P100D. It’s no surprise that Tesla say this thing can go up to 620 miles. It’s extremely aerodynamic, as well as being lighter than the P100D, and has a larger battery.
However, what’s most interesting is the motor configuration. Both vehicles with the Plaid Powertrain feature three motors; one in the front and two in the back.
Combined, the motors will produce an estimated 920 kWh of power, or about 1200 horsepower. That’s just a little less than the 1200 horsepower that the $3 million Bugatti Chiron produces.
We’ll get a preview of the Plaid Powertrain later this year when the new Model S refresh is released, but we won’t truly see its full potential until the Roadster a few years after.
We’ve already covered the battery size, but that’s not really an ‘upgrade’ as such, it’s just adding more cells. However, we know that the Roadster won’t be sticking with the older, less energy dense Panasonic 18650 cells. It will either move on to the Panasonic 2170 cells that can be found in the Model 3, or move on to a completely different new type of cell. This is something that Tesla could be working on with one of their acquired companies, Maxwell Technologies.
All that sounds great, but there’s one more update which would be very important to the success of the new Roadster; the battery management system.
When the Porsche Taycan was released last year, one of its main selling points was its ability to perform repeated accelerations without overheating. This is something that the Model S P100D lacks. Owners report it taking over 30 minutes to precondition the battery, only to find that it needs cooling after a few accelerations.
To improve upon this, Tesla is expected to integrate a new cooling system into the Plaid powertrain. It’s effectiveness has been estimated here:
Ability to remove heat (Watts / ˚K)
Plaid Battery Cooling
Model S P100D
Old Original Model S
But it doesn’t stop at the BMS, the 200 kWh battery pack should allow the Roadster to travel 620 miles at highway speeds. For the purposes of comparison, a Lamborghini Aventador can travel around 400 miles on a single charge, based on Lamborghini’s fuel efficiency figures.
With this new battery system, the Roadster should be fully capable of repeated accelerations, with peak performance from the battery always being available. It should show similar characteristics of a ICE powered track car.
Forces and Aerodynamics
Tesla usually makes a big thing about the drag coefficient of their vehicles, making sure to announce it in the cars release presentation. Of course, it’s a highly important statistic, especially for an electric car. However, a statistic was omitted from the Roadsters launch ceremony.
It may be that Tesla simply wasn’t close enough to the final production model of the vehicle to accurately predict the drag coefficient. We do know that the prototype model of the Roadster didn’t have any wing mirrors. The lack of wing mirrors is something that Tesla was aiming to incorporate into the final design once it had passed government regulations.
Either way, its obvious that the new Roadster must be pretty slippery in order to accelerate so quickly and reach such a blistering top speed. Additionally, battery powered nature of it means that there is no need for an air intake unlike say, a Bugatti Chiron.
We can predict the Roadsters drag coefficient based on the figures for the other cars in Tesla’s lineup, as well as other cars from different manufacturers. Here’s a table of drag coefficients for different vehicles:
Tesla Model S
Tesla Model 3
Original Tesla Roadster (2008)
Original Tesla Roadster with Aero Kit (2014)
Second Generation Roadster (est)
One notable exception here is the Volkswagen XL1. Volkswagen specifically designed it to have the lowest drag coefficient possible. Consequently, they made it electric, removing the need for air intakes. Moreover, the rear wheels are covered to stop vortices of air being formed. This is a similar design approach to Tesla with the Model 3, it just doesn’t look as nice.
When accelerating from 0-60 as quick as possible, grip with the surface is even more important than aerodynamics. Fortunately, the new Roadster doesn’t disappoint here.
The prototype version of the Roadster that Tesla was using for demo rides with spectators was using Michelin Pilot Sport Cup 2 tires. Despite being performance oriented, these are fully road legal, and don’t come with a hefty price tag of tens of thousands of dollars like the tires on many other hypercars.
In fact, a set of 4 of the tires currently retails at $2000 on tire rack. Hardly unreasonable for a $200,000 car.
Without developing their own tires in house, which, wouldn’t surprise me given Musk’s ideas about vertical integration, Tesla seems to be using the best tires they can find for the Roadster here. They’re not too expensive, great on the track, whilst still being good on the road.
What does the SpaceX options package bring?
The new Tesla Roadster is not the first time Musk’s companies, Tesla and SpaceX, have collaborated. In the past, they’ve worked together on several projects including partnering to create new materials for use on earth and in space.
According to Musk, the SpaceX options package will feature ’10 small rocket thrusters arranged seamlessly’ around the car. These would be embedded into the design, such as in the rear bumper, and most likely won’t be easily visible.
He later went on to state that the rocket thrusters would be cold gas thrusters.
Cold gas thrusters have been used on many experimental vehicles in the past. They’ve even been trialed on motorbikes to allow them to travel round corners faster without slipping off the track. As you can probably imagine, the turning effect of a rocket thruster is only dependent on the kind of stresses the material can handle and the thrust that the thruster can produce.
The Roadsters internal computer could apply this concept top improve handling around corners. For example, when the car sensed that it was skidding, it could fire some of the rockets outwards to provide some force in the opposing direction to the cars movement. For example, if the car was trying to skid off a corner, the thrusters would force is back into he corner.
Consequently, the velocity the the Roadster could take corners at would no longer be limited by its grip to the road. Really, it would simply just be down to the force that the thrusters can provide, as well as the stresses that the materials it is attached to can handle.
In terms of acceleration in a straight line, the Roadster could essentially go as quick a Tesla wanted it to. Musk even stated that it would be possible for the Roadster to do short hops, though he wasn’t sure if the Roadster could do that legally.
Another use case of the thrusters would be to replace a spoiler. At high speeds, the airflow around the spoiler produces a force down towards the ground. This force results in more grip on the road. The thrusters could replace this by pointing upwards when the car needed more grip.
In addition to all that, the Roadsters will simply just be run on an electric pump which is powered by the battery, making them eco-friendly.
Conclusion: Are Rockets Even a Good Idea?
It’s fair to say that small cold gas thrusters spread around a car seems to have huge potential. If anyone is going to innovate, it’s usually Tesla, so we may be witnessing the start of a trend.
Despite this, it doesn’t seem to be something that would be useful for the average person. Hence why Tesla is selling it as an option on an already expensive and niche car.
Alone, the Roadster is likely to live up to its goal of being a ‘hardcore smack down to gasoline powered cars’. Even without the SpaceX options package. With the package, however, Tesla is aiming to smack gasoline powered cars so far into the ground that they become obsolete and useless. To use Musk’s words, “Driving a gasoline sports car is going to feel like a steam engine with a side of quiche.”
The acceleration that the rockets would provide is just the tip of the iceberg. All the potential improvements in handling are so unimaginably large that we could see the Roadster setting speed records that nobody thought possible.
If this is the case, it’s very likely that other manufacturers will immediately jump at the opportunity to use this technology, especially since Tesla will probably make all the patents free to use.
One things for certain, the new Roadster is going to be a very exciting vehicle to look out for. Even if we have to wait till 2022.