If they went for PML Flightlink in wheel motors they would have a far better car, with about 700hp and 4.0 second to 60mph. An inboard electric motor is outdated and a bad design. Wheel motor/brakes are lighter more powerful and give more battery space so greater range. The Tesla design is not very good.

...then you will be required to hand over your cash in advance, with no guarantee of actually getting a Roadster. If you are lucky enough to get one, you might be driving it along one day when Tesla operatives jump out of the hedge, take it back, and leave you stranded.

Oh and if you have ANY kind of problem with the car, from flat tyre to major engine malfunction, when you try and contact Tesla, you'll get a recorded message telling you that it's your own fault.

it has gone round the top gear test track in the hands of the stig

... are supposed to be featuring it this autumn.

We know the future of the car is electric, and that means silent, heaps of torque, cheap to run and maintain and no emissions. We don't know yet how the electricity will be fed to the motors- Tesla has standard lithium-ion batteries, the British Lightning GT has far better Nanosafe batteries, and Honda and Mercedes-Benz have fuel cells. Li-ion batteries are expensive though, and Nanosafe batteries super-expensive. It will be interesting to watch how far battery costs will fall, or if fuel cells get lighter and cheaper. The reason the Lightning is so promising is because it can be charged in ten minutes, and doesn't need hydrogen fuel like fuel cell cars. A network of 3 phase chargers wouldn't be so hard to roll out, and you've got the overnight charge in the meantime. Even small electric cars will have a flat torque curve and luxury-car levels of quietness. Rear-wheel drive and 50-50 weight distribution won't be so difficult to do with electric cars. The future looks good!

I'm lucky enough to have driven the euro-spec version of the car and my god is it quick. At any (near) legal speeds there is not much that will touch it.

A few points:

1. It is not an Elise body, it is a new design and even a different material.

2. Until PML Flightlink motors have been shown to run at 100+ mph reliably - and stop a car from that speed - I will take the inboard design every time. The Roadster was design was virtually complete by 2005, not 2009. The Tesla motor is so compact that freeing up its space would not add many more batteries.

3. We will see both longer range and cheaper Tesla models in the near future that will be able to do almost any journey most people make. 300 miles is expected in their next saloon model. If you want to go on long road trips, don't buy this car. For the other 99% of the journeys people make, it is very capable, a lot of fun and will save you tens of thousands in petrol costs during its lifetime.

Doesn't anyone else think they seem to have made a lot of work out of something that should be relatively simple?

After all, the complicated bit (the chassis) is off the shelf, and they don't even have to make it.

The battery pack, motor and controller aren't exactly radical. Hard to believe there would be many problems here apart from maybe getting the battery performance to an adequate level for 'production' purposes.

What's really a surprise though is the problems with the transmission. It's not complex, and there are decades of knowledge of how to produce something to meet just about any set of requirements. All they had to do was go to one of the usual OEMs with a set of requirements & a development budget and I'm sure something suitable would have turned up very quickly - at least that's they way it works for everyone else!

What they were trying to do shouldn't have been this difficult. So the question becomes *why* has it been so difficult? And just how much money have they burned to do it?

I was expecting something to do with Tesla coils and humungus sparks, which I wonder if we'll get when something like this crashes... think massive batteries and lumps of twisted metal.... :)

Rear wheel drive is a nightmare is slippery road conditions. So living in the North of England I'd personally avoid it. They should be able to do really good 4 wheel drive though and without the weight of all those fancy limited slip diffs.

Continuous acceleration without any gear changes at all is nice too. Only had the pleasure of that with 2 wheels so far though.

Flames 'cause we all know those batteries will cause as many fires as petrol.

@Anonymous Coward

Yes it does look simple on paper doesn't it.

Unfortunately, three different transmissions from three top OEM suppliers kept breaking as they couldn't handle the instant max torque after a gear change. So Tesla's solution was to go back to their electronics engineers and remove the need for gears all together.

I'm not working for them, by the way, but I have been following the project closely and building the world's first production electric sports car was not without its ups and downs. If you can do better, call me when it is ready and I will tell you how it compares on the road :)

There are _so_ many reasons not to do what you suggest. Unsprung mass? You really want to die when you hit a small bump in a corner on a B-road because of rotten handling? (I know that yank tractors with live axles have done this for decades but that is no excuse!)

Standard diffs & centralised motor have the benefit that you don't need a complicated computer system monitoring the torque at each wheel all the time to prevent it veering off the road in the complete opposite direction to the one you are steering. Torque steer is an incredibly powerful tool for changing the yaw (and stability) of a vehicle. (+ whole host of other benefits like braking stability)

Plus I think (not 100% sure) that you need separate brakes (& not fly by wire brakes) to pass SVA or MOT.

Chris

are bad for sports cars (more unsprung weight), Colin Chapman will be turning ..

Yes you are correct. They aren't exactly doing anything special here - they are taking an existing car, tearing out all the good bits, and turning it into a golf-car. These things aren't much bigger than a smart fortwo and, other than the acceleration, perform about as well as a smart fortwo.

The only good thing about this whole mess is that it's a solid step towards electric cars for everyone - which when done correctly will far out perform internal combustion autos. It'll be fun!

But will it be able to toast and butter your breakfast muffins whilst driving it to work in the mornings , that be the critical question ?

So I plug it in to my fossil fuel powered standard plug socket? How does this help reduce my CO2 footprint? Or is it just bollox to sell another useless trinket? My £500 used Merc 190 D runs on recycled cooking oil and petrol engines can be modified to run on alcohol so why do we need electric cars?

Because there isn't enough land mass to grow the crops required to make all the cooking oil and alcohol required to run all the cars currently on the roads.

surely Direct drive would be best four wheels four motors... simple.

steering and suspesion is easy when your connections are wires...

Its just the right controller that is important...

One of the basic tenets of car suspension design, indeed a basic reason we have suspension, is to reduce the unsprung weight of the vehicle. This improves both handling and ride comfort. Adding the weight of in wheel motors compromises this and as such is not necessarily a good plan. If you look back across the history of real sports cars (i.e. not made in the US, can go round corners, have suspension not taken from a prairie wagon) you will see lots with inboard disk brakes on the rear diff and other similar efforts to move weight from the unsprung to the sprung areas.

"Rear wheel drive is a nightmare is slippery road conditions"

Not if the engine is also at the back.(as is the case here). I've owned several rear engined NSUs. Superb road holding.

Mine's the one with the mains lead sticking out of the pocket..

"Why do we need electric cars?"

1. Big combined-cycle power generators are pretty damned efficient (50%+) because they run at more or less constant load. Even taking into account the transmission losses, it's still better that achieved by a fossil-fuelled car (<30%).

2. Can you run your car on nuclear power or solar? Thought not. Using electricity allows you to use a whole variety of raw fuels. There's not enough land available to produce enough alcohol/cooking oil to power all the cars.

That's why.

Charge it here: http://teslafounders.files.wordpress.com/2008/07/slide040.gif

@Solomon Grundy

If you knew what you were talking about, you would know that the only thing it has in common with that existing car (the Elise) is the dash and the front suspention. The chassis, the body, the rear end set-up, everything else is all brand new.

Save your Smart ForTwo comments for when *you* have driven one.

The cost of these electric cars means that the majority of motorists would never be able to afford an electric car. While it is true, electric cars are the future and will aid towards reducing the Carbon Dioxide emitions. Who exactly is going to buy one.

Questions to ask:

Why should someone buy this car when they buy a different sports car for same amount of money that will out perform it?

Why would you want a car that needs hours to refuel when you can buy a petrol car and refuel it in minutes?

Only a rich show off would even buy this car so they can jump on the "enviromently friendly" band wagon waving their eco friendly, impracticle, unaffordable trinket at the rest of the world. Its a pretty neiche market to say the least.

I personally hope that the company goes bust, their patents expire and someone with half a brain, thats half more than anyone involed so far, reinvents the technology in a more pracital form.

You've clearly not got much of an understanding of this car have you? They are not taking an existing car and just putting electric gubbins in it. The chassis is different to an Elise - granted, it's based on the same technology and roughly on the Elise chassis, but it isn't the same.

RE: What Transmission? - A motor in each wheel isn't simple, it's anything but, it complicates ride and handling, not to mention the problems with controlling those wheels to manage the power (granted, they could go to someone like ProDrive to sort that).

The maths say the lightening can't be charged in 10 mins without some serious current and a cable equally serious, but we shall see.

The figures quoted for the Tesla Roadster are - literally - incredible. Here's what you do:

1) Work out how much electricity 1c buys

2) Use that to derive its claimed fuel consumption in J/mile at the wheel (assume 100% transmission efficiency if you like)

3) Using typical thermal and mechanical efficiencies for a petrol driven car, work out how much petrol would be needed to provide those joules at the wheel

4) Convert to a miles/gallon figure

And you find that they are claiming to have a sports car design which, with a standard petrol engine, would be doing something like 160mpg.

Yeah. Right. Is Moller involved in this somewhere?

I note that you posted up an edited version of a post from a hundred years ago. I've reposted the original below:

---

The cost of these new "cars" means that the majority of horse owners would never be able to afford one. While it is true, "cars" are the future and will aid towards reducing the horse crap on the roads. Who exactly is going to buy one.

Questions to ask:

Why should someone buy this "car" when they buy a horse for much less money that will out perform it?

Why would you want a "car" that needs to refuel when you can buy a horse and feed it hay?

Only a rich show off would even buy this "car" so they can jump on the "modernist" band wagon waving their oh-so-trendy, impracticle, unaffordable trinket at the rest of the world. Its a pretty neiche market to say the least.

I personally hope that the company goes bust, their patents expire and someone with half a brain, thats half more than anyone involed so far, reinvents the technology in a more pracital form.

Won't be ready for the masses for another 20+ years i expect. Get one carries four, takes me to work and back, reliable, doesn't take all day/night to charge, and costs 15-20k and i might think about it. Until then it's just a fancy piece of hardware for the ultra-rich to fool with and look like the gibbons they are.

OK, I'll bite:

[FYI, Tesla quote "around 1c/mile", assuming off-peak electricity]

1) Off-peak electricity is arounf 2.7c/kWh in the states, so 1c buys 0.37kWh

2) 0.37 kWh = 1,332,000 J/mile

3) Let's take a petrol car:

30 MPG is 9.4l/100km

1 litre of petrol contains 10 kWh per litre

So we're using 94 kWh/100km

Or 1.5 kWh/mile

Or 5,400,000 J/mile

Conversion efficiency is around 27%, so at the wheels we need

0.27 x 5,400,000 = 1,458,000 J/mile

4) Scaling that back up to get a "MPG equivalent", that makes

1,458,000/1,332,000 * 30 = 33 MPG

Sounds perfectly reasonable for a little 2-seater car.

How on earth do you get to 160 MPG??

boo. i was expecting death rays.....

'I personally hope that the company goes bust, their patents expire and someone with half a brain, thats half more than anyone involed so far, reinvents the technology in a more pracital form.'

It's the same with any new technology; early adopters pay a premium, the manufacturers work out the kinks and the mass production companies make the money.

The real star of the next generation cars has to be the Chevvy Volt due in 2010; a plug-in hybrid (think of it as an electric car with a small petrol engine, rather than the Prius' big engine with a back-up battery). It's a practical family car, can be charged from the domestic supply and is designed so that most people on most journeys won't need to engage the engine.

http://gm-volt.com/

Pity it's so bloody ugly in that uniquely American chunkier-than-thou style. Hopefully one of GM's European marques will restyle it before we get to see it on the right-hand bank of the Atlantic.

"These things aren't much bigger than a smart fortwo and, other than the acceleration, perform about as well as a smart fortwo."

How the hell did you work that out? It out accelerates a smat fortwo and will out handle it (I don't know for sure, but it probably has a lot lower center of gravity and is probably better balanced) I asume what you are saying is that it will only reach the same top speed, which as long as it will do over the speed limit is a pointless and, frankly, stupid thing to say.

>

> Or 5,400,000 J/mile

>

> Conversion efficiency is around 27%, so at the wheels we need

>

> 0.27 x 5,400,000 = 1,458,000 J/mile

>

What you should have done is

5,400,000 / 0.27 = 20,000,000

5,400,000 J/mile at the wheel requires 20,000,000 J/mile in the tank.

>

> 4) Scaling that back up to get a "MPG equivalent", that makes

>

20,000,000/1,332,000 * 30 = 450 MPG

I think your assumptions about 100% efficiency for the electical engine and costs aren't quite right.

>>>Because there isn't enough land mass to grow the crops required to make all the cooking oil and alcohol required to run all the cars currently on the roads.

Oh, and I suppose there IS enough coal, oil, etc. to generate enough electricity to recharge all the cars currently on the roads, then?

He's not referring to the efficiency of the fuel. The point he's making is that to use an electric car doesn't eliminate pollution at all - it merely shifts where the pollution is made, from your tailpipe, to the smokestack.

No, I'm following Ian Johnstone's suggested calculation.

- You've multiplied that the wrong way (as indicated by the ridiculous 450 MPG figure) - I calculated the power from burning fuel @30MPG, then multiplied that by 27% to get the power at the wheels.

- Yes, I *know* it's not 100% efficient through the drivetrain (it's more like 90%), but this assumption is enough to show that the "1c/mile" figure quoted by Tesla isn't that wide of the mark.

Yes, it assumes you can charge it on cheap electric.

Yes, it's a bit optimistic.

But it's not wrong, and it's not a lie.

The overall energy used by an electric car is *close* to that used by a fossil fuel car. Of course it is - there's not massive wasteage at any point so that's what you'd expect. Conventional cars and electric cars are both pretty good solutions.

Claiming that one is *magnitudes* better than the other is not going to fly. It's just not true. [That goes for the eco-weenies as well as the petrol-heads.]

Midwestern Canada has plenty of cheap, clean hydro power. A Tesla would be at home in a province like Manitoba.

/me still looks for his ZENN car some day

So, how many KPG does that figure out to in litres of whale oil?

Paris, because she likes getting oiled up.

If electric cars actually became common (perhaps at least 10-20% market share?) it would make a lot of sense for car parks to have electric hook ups in either all parking spaces, or at least in designated areas of the car park. Perhaps instead of single ticket machines in odd places they would put smaller devices nearer to the spaces, linked in to the electric distribution to charege you for teh electric as well? Not necessarily every space, but for a cluster of spaces.

Some uses such as long distance trips would be a problem, but it would probably be good enough for a lot of people... a lot more than otherwise. It could charge up while you are at work, do your shopping, go to the cinema or whatever else you do. Even if it's only on for half an hour or an hour it would still probably give you that bit extra mileage.

Where do you plug it in? As things are, I'd have to run a mains lead out the window and across the pavement, where people would trip over it and/or minipikeys would unplug it and squirt superglue into the socket. Assuming the bloke next door hasn't parked his van in front of Larrington Towers.

I see no sign of dedicated electric motorcar recharging infrastructure coming any time soon.

@Justin: "Rear wheel drive is a nightmare is slippery road conditions"

Nonse. It's /fun/. They really spoiled the Transit when they switched it to FWD...

Why does the thing need a transmission anyway? Just stick a separate motor on each wheel, with multiple centre-tapped windings on the stators (Why centre-tapped? You wouldn't be asking that if you'd ever designed a full-bridge driver.) Then you "change gears" by energising different combinations of stator windings -- the same way as it's already been done in washing machines for much longer than it takes for a patent to expire.

For a further refinement, do away with the steering rack! Let each wheel steer independently, and control the steering by varying the relative speeds of the motors on each side: the car will turn towards whichever side is moving more slowly.

The charging problem would be easiest solved the same way as builders manage with cordless drills: by having exchangeable batteries. Garages with the required heavy-lifting gear could swap out your batteries for a fully-charged set in minutes.

Surely this is the ideal opportunity to make some more wildly inaccurate, bigoted criticisms of the Toyota Prius. Where are they?

Please, I need to get another second-hand Prius soon and these constant criticisms help to drive the second-hand price down to something I can afford.

<<For a further refinement, do away with the steering rack! Let each wheel steer independently, and control the steering by varying the relative speeds of the motors on each side: the car will turn towards whichever side is moving more slowly.>>

That's how you control a "zero-turn" ride-on mower. Anyone who's tried driving one would understand why it's a BAD IDEA. As soon as one of the driven wheels slips, or it's transmission fails, the whole thing swerves violently and uncontrollably to that side. Even at 10MPH it's terrifying. Since buying the thing last year, I've driven it into a ditch after hitting a patch of mud, and then walloped the side of my car with it when a throttle return spring fell off while I was parking it.

Happy to oblige.:-)

The Prius is a poor performing, evil handling joke.

Last time I tried one, it struggled to beat 40mpg, acceleration was pitiful, it had dangerously poor grip (thanks to those rock-hard tyres) and cornered like it had a sack of cement in the boot.

Just awful.

Keep it up. .. but you were supposed to be insulting my Prius, not my zero-turn lawnmower! I have to admit though, you described the performance of the lawnmower pretty well!

OK, point taken. You could still do it, though -- you'd just need to get your speed information from an accelerometer array (which will pick up the speed of the vehicle) and not from the Hall-effect sensors on the wheel motors.

Like the way the best hi-fi valve amplifiers take negative feedback from the secondary windings of the loudspeaker transformers -- any non-linearities introduced by the transformer will be counteracted by the action of the feedback loop. Philips even tried to go one step further and built a loudspeaker enclosure which took negative feedback from the speaker cone, but the idea never really caught on.

It is a totally ficticious piece of nonsense that the plantet does not possess enough land to grow enough biomass for ethanol powered engines. How up to date are you with biofuel research? The technology is at a stage where almost every agricultural plot in the western world could be put to dual use i.e. food and fuel. Take for example a field of barley, all we use for consumption is the tiny grain from the tip of the entire plant. It is perfectly possible to bio-convert the rest of the plant into bioethanol. This represents just one of the MANY waste products which could be used as a substrate.

The white paper ( http://www.teslamotors.com/display_data/TeslaRoadsterBatterySystem.pdf )on the batteries of the Tesla states they contain up to 53kWh of energy or the equivalence of 8 litres (2.11 gallons) of gasoline. If you then factor in the action radius of ~220 miles you get the stated 100 MPG. Considering the cost you get 220 miles for 53kWh*2.7c/kWh = 1.43$ quoting Paul Barnfathers number.

That's 220 miles for the cost of half a gallon (? don't know the price of gas in the states) which will be 440 MPG costwise which is what MPG is an indicator for in any case. This is truly an amazing car!

Does this conform to the new regulations as mentioned at:

http://www.businesslink.gov.uk/bdotg/action/ruDetail?type=REGUPDATE&site=210&itemId=1081130778&r.s=email&tc=EA014

No, no. You don't understand how steering works in a real car. It does NOT work by the car tyres being turned to lie on the tangent of the circle of turning.

In a turning car, the tyres are always slipping. The slip-angle determines the sideways force of the road onto the car, and that is what makes the car go round the circle.

Putting more drive on one side than the other will TURN THE CAR, but leave it going in a straight line. It's called an oversteer skid. The way that the car nose points through a corner has very little in principle to do with the way its CofG actually moves. Similarly, the restoring-force on the steering-wheel (aka "feel")has no relation to the amount of grip available.

Its pretty much the whole art of car design to make all these effects feel to the driver as if they are the same, so that the car becomes driveable. Colin Chapman's book is an excellent introduction.