Road Test: Tesla Roadster Sport

Tesla Roadster Sport, the electrified roadster. 

400 Newton Meters. At zero rpm. The figure would sparkle interest from any automotive connoisseur, furthermore when it comes packaged into a package as seductive as the Very Orange (it’s the real name of the paint jobe) Tesla Roadster Sport entrusted to us for this road test. Dressed with vast expenses of carbon fiber, from the front splitter to the hood and the numerous inserts of the Premium Executive Carbon Pack interior, the car certainly looks the part under the grey skies of this inglorious fall day. We hurry out of Geneva’s outskirts to bag some photography in dry conditions. At cruise speeds on the freeway, tire roar and wind noise dominate. Hard to say if the drone of a good old 4 cylinder engine would be more enjoyable, cruising is hardly the diet of choice for a hardcore roadster anyway. Standard equipment includes AC, an elaborate, multi-screen trip computer with touch screen, a radio and iPod interface.

Behind the wheel, the familiar binnacle shows on the left a speedo graduated till 250 by 30 kph increments – a bad habit that the Roadster shares with its Lotus cousins – with a parallel scale for engine rpms going from 0 to a 14’000rpm redline. There’s no gearbox in this car, the electric motor torque is such that it can both offer meaty acceleration and a 201 kph top speed with a fixed 8.28:1 drive ratio. Speed and rpms are therefore in direct relation. On the right hand side, a power indicator going clockwise from 0 to 200 kW (or 271 hp) for consumption, and from 0 to 40 kW for regeneration. Unlike most hybrids, the Tesla Roadster does not use a brake pressure splitter to channel energy between the battery recharge and thermal dissipation in the disc brakes. Engine braking is very pronounced when the throttle pedal is lifted, to the point where the middle pedal can be made useless in fluid driving conditions. The throttle needs to be feathered to coast normally, a follow car could otherwise be surprised by the amount of deceleration while brake lights remain off.

The battery pack is nested behind the seats in the compartment otherwise devoted to the Toyota engines that power the Lotus range. No less than 6831 Lithium cells whose thermal management is given great care, with a liquid cooling system that runs to a large front intercooler topped by two fans. Their lifespan is rated at 7 years or 160’000km and their replacement listed at 13900 CHF. At 120 km/h, the power indicator hovers around 25 kW (33 hp), so there’s around 250 hp left on tap under the right foot. Time to head for the wine country hills.

Pedal to the metal out of villages, acceleration from 50 to 80 kph (or much more at your own risks) are hilariously quick. The instant throttle response and the impressive, constant shove from the engine make for a pretty unique automotive experience. A completely different one – and much less visceral – than the rage of an Italian V8 rushing to its 9000 rpm redline, but the electric motor whine has its own charm, reminiscent from futuristic spacemobiles seen in the Fifth Element, Minority Report or i-Robot, but jet planes also come to mind. Highly likely to be more attractive geeks than hardcore fans from seventies car memorabilia, but I found it definitely attractive. Socially responsible too as the Tesla Roadster makes very little noise overall. That is when the auxiliary fans are not triggered by repeated, intensive use of maximum power, in which case the car sounds like a rolling hairdryer, inside and outside.

On a twisty road with slow corners, few sports or supercars will be able to cope with the murderous acceleration of the Roadster Sport out of hairpins. No need to worry about apex speed or gear selection to keep the engine in a favorable rev range, torque is there, all the time, instant, relentless. Whatever the corner, response is immediate, decisive, making for effective and addictively fun progress. It’s only at higher speeds, well beyond reason in realistic open road conditions, that power starts to run thinner. At 4.42 kg/hp, power to weight ratio is respectable, but remains far from the 3.42 kg/hp of the naughtiest supercharged Elises. The cocktail would probably lose some of its punch in faster, flowing roads or tracks with higher peak speeds. It’s easy to find the reason in the spec sheet: maximum torque is constant from 0 to 5100 rpm (approx. 70 kph) while the 288hp power peak is reached at 6000rpm. From there on to the 14000 rpm redline, it’s a slow downhill slope. At 10500 rpm (approx. 150 kph), there is only 230hp left. A two gear system was on the development program for the Roadster, but had to be dropped for reliability reasons in favor of this simpler, direct drive solution. Reach is there, but sustained thrust isn’t.

Un-cooperating weather made it difficult to dig deep into the Roadster’s road handling, the sparse thread of the Yokohama Advan A07 calling for caution on showered tarmac. Given the car’s sticker price, carving its pretty orange noise in a ditch was not an enticing perspective. Damping is a good surprise, there’s no needless harshness while the immediacy of reactions is well preserved. Steering is not assisted and heavy, but it bothered me a lot less than on the Elise Club Racer recently tested, most probably because the Roadster does not have to be a momentum car and scrape the last tenth of cornering speed, there’s plenty of straight line performance to make enjoyable and expedient progress. At road pace, the weight premium remains surprisingly unnoticeable. On our corner scales, the Roadster comes in at 1275kg with a pretty radical balance (65.1% rear, 34.9% front), 45% more than the lightest contemporary Elise (878kg). A benefit of the weight distribution is that, in spite of abundant torque, straight line traction is not an issue, even with the electronic nanny switched off. I found the brake pedal feel average, a bit amorphous. Interestingly, the wheel base of the Roadster is longer by a whole 51mm compared to the Elise chassis.

After a 174km test loop mixed between freeways and country roads, 77% of the battery charge are gone, which places total range at 226km (Tesla claims 340km). A range which is theoretical since there is no practical way to tap it tall and plan for a hypothetical charging station near the location where the batteries will run empty. The prospect of waiting a full 3 hours to fully recharge if said charging station is capable of dispending the 70 Amps necessary to a fast refill. As it is always the case, we land far from normalized figures, our effective power consumption netting out to 247.8 Wh/km vs a theoretical 164.7 (56 kWh/340km) and an indicated 203 Wh/km on the trip computer. At the average cost of electricity in Switzerland (0.22 CHF) or France (0.13€ without VAT), energy cost remains very low: 5.45 CHF/100km under the assumption of a 100% charging efficiency. Transposing the energy figures with the energy content of gasoline (9.7 kWH per liter) yields an equivalent gas consumption of 2.55 L/100km. A figure which does not take into account any loss in the charging process, but which provides a good indication of the range of figures in play.

A caveat though: if the figures look attractive, practical reality is otherwise. Battery gauge anxiety is a real concern. The car can be charged on any 220-240V outlet, but a high power 380V utility connection is highly desirable. With 70A, a full charge only takes 3 hours, but with a conventional 10A 220V socket, you are looking at a full 22 hours. It is nearly impossible to plan a 300km dash through alpine passes unless you schedule a lengthy lunch break in a suitable charging location. Electrical range is totally viable in a daily commute scheme, but commuting is not what an open air roadster should be primarily used for.

Other issue, the price list. The Tesla Roadster Sport lists for 142’200 CHF, and a trip down the options list may have a dizzying effect. With a handsome spec like our test car, list price fetches well over 170’000 CHF. A niche product for well healed early adopters looking to drive something distinctive, a pretty unique automotive experience and the image of an environmentally responsible sports car.

In the U.S., the whole contingent of Tesla Roasters is sold out as the focus shifts to the spring 2012 of the Model S Sedan. European countries still have cars on allocation and the Roadster is still on sale on our shores. The swiss market has responded positively, with more than 100 cars registered since the 2009 launch. Petrolheads now have a new alternative open to them: to become Electronheads.

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