Today’s AutoSpeed article on electric vehicles is, as the box in the article states, based on a seminar given by Dr Andrew Simpson.

Dr Simpson produced the paper that we used as the foundation for the Assessing the Alternatives article we ran about a year ago – it’s amongst the very best of articles you’ll find in deciding which fuels vehicles should be using.

Andrew Simpson has just returned to Australia from four years in the US, where he worked at the US Government National Renewable Energy Lab in Colorado, and then was a Senior R&D engineer at Tesla Motors.

I found his seminar quite riveting: it changed my views on a host of subjects relating to electric cars.

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Over the years I have built plenty of simple structures that I’ve wanted to be both light and strong.

Those structures vary from little brackets that might be holding something in the engine bay, to complete human-powered vehicles that I trust my life to.

In all cases, the starting point for the design is to consider the forces involved. How does the force of gravity act on the structure? What direction do braking loads act in, or short-term transient loads like suspension forces? Will this tube be placed in bending (not so good) or is it being subjected to compression (good) or extension (better)?

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Back in this blog I mused about how little power is actually needed in a car. My benchmark was not acceleration or top speed. Instead, it was the ability of a car to climb hills at the open-road speed limit (here in Australia, 110 km/h).

Based on dyno tests and the hill-climbing performance of my diesel Peugeot 405, I decided an at-the-flywheel figure of 35 kW/tonne was about the right minimum.

I applied that idea to electric cars, where for reasons of lightness, battery power consumption and cost, an electric motor that errs on the side of smallness makes sense.

A number of comments were then made that this was completely wrong, that electric motors don’t work in that way (apparently, an electric kilowatt is different to a petrol motor kilowatt!) and so on. However, I saw no evidence that suggested a power/weight ratio of about 35kW a tonne was not the minimum for a car to be competent on the open road. (And a reasonably aerodynamically slippery car, at that.)

Recently, I’ve driven three cars that have a instantaneous power output display on the dashboard. These are all Lexus hybrids – the LS600hL, the GS450h and the RX400h. The latter’s display is shown above.

With this gauge I was able to see exactly how much power was being transmitted to the wheels, irrespective of torque curves, throttle position or anything else.

The actual power going to the wheels.

The RX400h weighs-in at 2040kg – say with my body mass, 2130kg.

Typically, I used in normal driving – even sporty urban driving – an indicated 50kW or less. That’s just a little under 24kW/tonne.

Getting into it more strongly, 75kW showed on the dial – but I stress, this was now going harder than most people would drive most of the time. That’s a power/weight ratio of 35kW/tonne.

To get 100kW (or higher) showing on the gauge, you had to be clearly pushing the car hard.

And 200kW? Full throttle and with lots of revs – completely unlike 99 per cent of daily driving.

I already know from the Peugeot that, if the car is being driven well, 35 kW/tonne is enough for open road driving – and now I know that it’s also sufficient for even quite sporty urban driving.

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People who have been into modified cars here in Australia have for decades known of the incredible bargains that can be had from Japanese-importing wreckers.

Because of the speed with which Japanese drivers discard near-new cars, the drivelines – or even complete front halves of cars – can be bought amazingly cheaply. Engines and gearboxes boasting late model technology, for less than the cost of having an old clunker rebuilt. It’s simple – buy a locally-delivered car and then install a new Japanese-import driveline having much greater performance. Over the years I’ve done this twice – and both times got a tremendous car for the money.

And now there’s a whole new and exciting Japanese-import field opening up.

Because Japanese manufacturers have led the world in the creation of hybrid petrol/electric cars – the first was built over 10 years ago – and because many were sold locally in Japan, hybrid car parts can now be sourced out of Japan at the same ridiculously low prices.

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http://www.greentechmedia.com/articles/should-tesla-motors-sell-out-1084.html

An interesting opinion article, especially in the context of the global financial crash that has occurred since this piece was first published.

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As we covered in Analysing Road Car Drag, most aerodynamic drag of current vehicles is created by separation pressure drag. Put simply, this is reflected in the size of the wake – the cross-sectional area of the disturbed air dragged along behind the car.

The most slippery vehicles in the world – the solar race cars – have reduced separation pressure drag to the extent that the other types of drag (eg viscous drag, induced drag and interference drag) become more important.

But in all conventional cars, it’s separation drag that remains the big one.

Now this gives rise to a rather interesting idea. Imagine you’re standing alongside an empty road. The day is a still one – there’s not much wind blowing. A car is rocketing towards you along the road, travelling at perhaps 100 km/h. It will pass close by to you. It grows in size and then roars past.

Now – what do you feel?

Clearly, you will be able to feel the wake – the eddies and turbulent air indicative of the aerodynamic disturbance of the car. This disturbance will take into account the separation pressure drag and the frontal area of the car – the two when multiplied form the vast majority of the actual aero drag that’s experienced by the car.

And, equally clearly, the smaller the air disturbance that you can feel, the greater the slipperiness of the vehicle.

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Here in Queensland the State Government has issued a discussion paper entitled Improving Sustainable Housing in Queensland.

The paper canvases a range of requirements the government is considering implementing for the construction of new houses and units.

I think it astonishing how little government regulation has been applied to the energy efficiency of housing. Especially in the context of the media attention given to fuel-efficient cars, there seems to have been a deathly silence on what is surely the far more important area of housing.

After all, a typical house is going to be consuming energy for something in the order of five to ten times as long as a car, and will be doing so most hours of the day and night.

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I’ve always been a little scornful of those parents who proudly proclaim their children’s knowledge and interests, knowledge and interest that are only a reflection of their parents’ particular knowledge and interests.

You know: “Benjamin can name all the players in the Adelaide Football Club”, proudly says the football fan – and stuff like that.

But now in having a child of my own, I can see that it happens rather naturally – the child is interested in what the parents are interested in, and that knowledge is transferred without effort.

So the fact that my four year old, Alexander, when looking over my shoulder at a book on cars that I am reading, can identify the old Citroens, Jaguar E-Types and Porsches, is perhaps not much of a surprise.

But this familial socialisation becomes interesting when you consider change, and the future.

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http://www.smh.com.au/news/national/when-is-a-bike-not-a-bike-when-its-electric/2008/06/15/1213468240544.html

As electric bikes get more powerful, and lose their pedals, riders risk breaking the law. But what should the law be? Unlimited power? And how is that power to be measured?

At least one AutoSpeed reader is riding an electric vehicle that looks pedal powered, and looks legal in power, but is capable of at least 5 times the legal power output in short spurts…

When I heard of that reader I just laughed.

But if the law in its current form prevents people making use of efficient, low pollution and cheap transport, surely it’s in need of review?

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