Here is a car I did not expect to ever see on the road; a Tesla Roadster! After initially thinking I was looking at a Lotus Elise, the black tail light surround triggered a light bulb moment that this car was rather more unusual. There is quite the story behind the Roadster, as both Martin Eberhard and Elon Musk have revealed in some remarkable transparency over the last few years.
The story of Tesla with its expansion with a wider range of vehicles and beyond into battery production and household battery banks is reasonably well-known, and I am not going to explore those within this article, but what I did find interesting is that some aspects of the development story has been revealed by Eberhard and Musk in interviews, shareholder meetings and presentations.
The Tesla Roadster is quite a landmark vehicle really, as the first of a new wave of electric vehicles after the few late-nineties CARB-inspired EV conversions of regular production models from Ford, Honda, Nissan and Toyota – and not to forget the GM EV1.
You may already know that electric vehicles go right back to the early days of the automobile, when they provided a viable alternative to what were then cantankerous mechanical contraptions, whether internal-combustion powered or external – in other words, steam – particularly before the electric starter was introduced from 1912 and gasoline vehicles became dominant.
This (largely unchanged) 1931 Detroit Electric is one from the latter end of the early electric car period, although Detroit Electric persisted until 1939. It is interesting that it took the best part of a century to make a significant improvement in commercially-available electric range. But as well as the wooden artillery wheels, another notable anachronism is the tiller steering.
But back to Tesla, which was founded by Martin Eberhard and Marc Tarpenning in 2003, after a drive of the AC Propulsion tzero which demonstrated via its AC induction motor that an electric car could accelerate faster than most sports cars on the market. They recognized that there was the opportunity to get in on the ground floor of the ‘proper’ electric vehicle resurgence.
Tesla was incorporated in July 2003, with the name chosen to honour the inventor Nikola Tesla and established their premises in Menlo Park, just south of San Francisco. Apart from some lofty goals relating to the ability of the new car, their initial business plan also mentions the other key which enabled the whole idea to proceed, which is the increased level of outsourcing of the automobile industry to supplier technology and components, so that a start-up car manufacturer would not have to develop every nut, bolt and sub-system themselves.
Early on many principal decisions were taken, such as not wanting to franchise dealerships so as to have a more direct relationship with the end customer, and that they had to base the car on an existing model because they were not in a position to do everything in-house. A key proposition was to target a high-end car which could support the cost of the cutting-edge technology involved. Lotus was quickly identified as the ideal partner, due to their engineering consultancy as well as having the small Elise sportscar that had the small size and light weight necessary not to overwhelm the capacity of the batteries.
At the same time as the a deal was struck with AC Propulsion to license to licensing their EV Power System and Reductive Charging patent that integrated the charging electronics with the inverter. On the other hand, the control system was analogue, which in clearly had to change in order to achieve optimal efficiency, so this was had to be completely redeveloped.
A key issue AC Propulsion lead-acid absorbed glass matt (AGM) battery pack was air-cooled, which was not adequate for the high performance (and thus heat production) required by the Roadster’s performance goals. I’d say this would turn out to be an advantage for Tesla in the longer term, as their liquid-cooled lithium-ion battery array of basic individual cells became a key aspect for their later production cars and other applications.
The first prototype, essentially an electrically-converted Elise, ran in November 2004 and was successfully tested, and in July 2005 an agreement with Lotus was signed to supply an Elise-based chassis. Due to the size of the chosen battery pack, the wheelbase was stretched by 2 inches, and Musk also insisted that the door sills had to be lowered to ease entry and egress. Due to the structural body changes, new crash testing was required. The suspension and braking systems were both redesigned, and new carbon fibre outer bodyshell panels were designed based on a styling concept by Barney Hatt of the Lotus Design Studio.
Musk has said that, again with hindsight, they would not have started with a Lotus because of the degree of change, but one has to wonder how much longer the process would have taken and now much more it would have cost to have done in-house? Musk also drove many design changes, such as upgrading interior trim quality and insisting on bespoke headlights rather than an existing component. While these issues added cost, they also added value for what was going to be an expensive car.
The Roadster was launched to the public at Santa Monica Airport on 19 July 2006, taking orders for a mid-2007 release. Musk revealed that the cars’ drivetrains were badly damaged by overheating when demonstrating the performance despite pumping ice water through the liquid cooling systems, and each car had broken one of the motor mounts.
But the cars had impressed many people and changed a lot of minds about electric cars and there was also a lot of press coverage. Very shortly over a hundred orders were placed. Subsequently ten engineering prototypes were used to finalise the cars’ specifications, and then a series of pre-production prototypes were produced from March 2007, for activities from validation, evaluation and endurance driving to crash testing.
After many developmental delays, rounds of additional investment and growing pains from a company perspective, including Eberhard being replaced as CEO, the first production vehicle was finally delivered to Elon Musk in February 2008. Production got off to a slow start, and not due to the US$109,000 price tag, taking approximately 6 months to reach 20 deliveries, while 200 vehicles delivered after the first 12 months. There were also some problems with the initial two-speed gearboxes being unable to handle changing gear, which led to their replacement by a single-speed Borg Warner unit.
The Tesla Roadster was the first production car to be powered by a Lithium ion battery, and the first to be rated with over 200 miles of range – in addition to the 3.9 sec 0-60 time this was the most significant aspect of the Roadster’s performance. This was due to the 53 kWh battery pack which consisted of 6831 laptop-type battery cells, which could be recharged in 3.5 hours on a 240V, 70A fast charger, or a whopping 48 hours if all you had was a 15A 110V outlet. A replacement battery would cost US$40,000 after its expected lifespan of 100,000 miles.
While media response was almost overwhelmingly positive, and test drive reports glowing, one fly in the ointment was an infamous review on Top Gear. Despite praising the car’s performance, Jeremy Clarkson was not as impressed by the handling and stated that range when driven on the track was just 55 miles; ok so far because any car experiences range reduction of that nature on track, but then he went on to claim the car suffered brake failure before footage showed the Roadster being pushed off the track. This was despite the car never having its battery go flat or having brake failure; in other words typical “entertainment” spicing-up from Top Gear. Eventually Tesla sued, and appealed after losing the initial case, but their libel claim was eventually rejected in the British High Court.
In July 2009 the 2010 model year Roadster was introduced, with an upgraded interior including a new display screen that could display performance data, adjustable suspension, improved NVH suppression, upgraded HVAC and a more efficient motor. A Sport version (above) was also introduced that featured an additional 40 bhp and cut the 0-60 acceleration time by an oh-so-important 0.2 sec.
On 27 October 2009 Aussie Simon Hackett set an electric car distance record when he drove 501 km (311 miles) south from Alice Springs in Global Green Challenge, at a speed of 50 km/h, crossing the NT/SA border and another 214 km before stopping with about 5 km range remaining, whereupon the car was recharged (with a diesel generator) before completing the trip to Coober Pedy.
Right-hand drive production began in January 2010; these along with all cars destined for markets outside North America were assembled at Wymondham, not far from Lotus’ Hethel factory, instead of the factory at Menlo Park in California. Also that month marked production of the 1,000th Roadster
Tesla launched its IPO on 29 June 2010, and shortly after the Roadster version 2.5, which featured new styling as well as further incremental improvements. Despite the update, and the car being launched in many more markets, available information on production indicates that 2010 saw a decline with only around 400 Roadsters being produced for the year.
The Roadster was launched in Australia in January 2011, costing AUD$209k, and somewhere between 12 and 20 were sold here; no wonder I was so surprised to see one on the road! 2500 were built in total before the Roadster went out of production when the contract with Lotus expired at the end of 2011, with the last cars sold outside of the US in 2012. Mind you, the model was doomed anyway because this also coincided with the expiration of Tesla’s exemption from having to fit smart airbags, an issue that also applied to Lotus. Around 1800 Roadsters were sold in the US, and about 575 in Europe.
Apparently the story has not reached its conclusion yet, as Tesla have stated they will bring out a new Roadster in 2019 (above is a speculative rendering done by Jan Peisert, and last year released a 3.0 package for owners to upgrade to an 80 kWh battery for US$29,000.
Postscript – I’m not sure if the production-vehicle EV distance record has been beaten, although last November a Japanese team drove a Suzuki Every van (that must have been filled with batteries) 813 miles / 1300 km around Ogata village at 30 km/h or so (18 mph). There has also been an electric Brighsun bus that did 623 mile / 1018 km trip on a single charge.