More on How Much Power You Really Need

Posted on January 29th, 2009 in Aerodynamics,Driving Emotion,Electric vehicles,Opinion by Julian Edgar

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.

Reader Stories…

Posted on January 27th, 2009 in AutoSpeed,Driving Emotion,Opinion by Julian Edgar

I hate to sound negative but long experience has taught me that if a reader emails that they have a great story for us, the very high likelihood is that it will never happen.

About once every two weeks I get an email.

Hi, I’ve invented a new type of turbo. I am sure you’d like to cover it.


I’ve developed a breakthrough fuel – you make it yourself. You should do a story on it.

Or, even,

You haven’t done a new car test on my car – it’s a XYZ. Would you like to drive it?

On the off-chance that something will actually eventuate, I always email back a semi-polite reply.

But then the turbo man doesn’t want to send me any real-world test results, or the person who makes their own fuel suddenly goes very quiet, or the person with the new car lives in remote, outback Western Australia.

New DIY Electric Car Opportunities

Posted on January 22nd, 2009 in Driving Emotion,Electric vehicles,Honda,Hybrid Power,Opinion,Toyota by Julian Edgar

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.

Bad, bad medicine…

Posted on January 20th, 2009 in Driving Emotion,Opinion,tools by Julian Edgar

I recently bought 300 old model engineering magazines.


As a novice owner of a mill and a lathe and an oxy acetylene set, I thought I could potentially get a lot out of these magazines. Plus, when I was a kid some 30 years ago, I was a member of a 5-inch gauge live steam model railway society – I have always maintained a very high affection and regard for model engineers.


But I think I’ll have to give up on reading these magazines.


Why? Well, they are just so damn depressing!


I always knew that model engineers were talented, but these guys (and they’re almost all ‘guys’) are just so good that they make me feel utterly ineffectual, ignorant and incompetent.

Why live in a hole like Sydney? Honestly…

Posted on January 15th, 2009 in Opinion by Julian Edgar

The other day I spent a week in Sydney. I’ve never lived in Australia’s largest city, and I can’t think of any possible situation that would compel me to do so.

Given that all of Australia’s major car magazines and most web media are located there, in my job, that’s a pretty big statement.

But I just can’t stand the place.

I have always thought the Opera House and Harbour Bridge are quite fantastic, as of course is the harbour itself and the ferries that ply it.

But having spent individual weeks on and off for the better part of 15 years working there, photographing modified cars and visiting car workshops, I think that most of the working class suburbs are just dives.

I don’t like the pollution (it gives me hay fever symptoms each morning until the breezes partly clear the air); I don’t like the fundamental arrogance of the residents (if someone sends us an email and it’s from Australia but they don’t say where they live, you can be certain it’s from Sydney – after all, doesn’t everyone live here?); I don’t like the traffic (Brisbane is bad but it doesn’t frequently stop for hours at a time); and on my most recent Sydney trip (a week ago as I write this), I didn’t like the even-more-than-usual run-down appearance in the suburbs – clearly, economic times in NSW are as bad as commentators suggest.

Should Tesla sell?

Posted on January 13th, 2009 in Electric vehicles,Hybrid Power by Julian Edgar

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

I’ve driven the latest auto transmission technology – and I prefer the old!

Posted on January 13th, 2009 in Driving Emotion,Mitsubishi,Opinion,Toyota by Julian Edgar

I think that the people responsible for the design and evaluation of cars sometimes lose the wood for the trees.

I am as much as an automotive technology aficionado as anyone I’ve met. I love technology like stability control, radar cruise control, telematics and hybrid petrol/electric drivelines. I look forward to pure electric cars, to better aerodynamic technology and to exotic materials use.

But I think that all new technologies must be assessed within the paradigm of what is currently cutting edge, and not just adopted because in just one or two respects they are advantageous.

I’ve recently driven two high performance cars with transmissions that are clearly, in important aspects, inferior to what is currently available.

The twin clutch SST transmission in the Lancer Evo MR can be lumpy in urban driving, and (worsened by the over-large turbo, high mass of the car and small capacity of the engine), has terrible lag off the line.

AutoSpeed in 2009

Posted on January 9th, 2009 in AutoSpeed,Opinion,pedal power,Reviews by Julian Edgar

It’s a new year – so what do we have coming up in AutoSpeed?

In short, it looks to be a great year.

First-up, we’ll be continuing our ‘How to Electronically Modify Your Car’ series. At this stage the series has about 15 parts – it may grow a little. By reading those stories, you can be taken from knowing literally nothing about electronically modifying a car to the stage where you can confidently make changes to analog and digital signals, and understand how car systems can be altered.

In the second half of the year we expect to cover an innovative development in DIY electronics that will put the power of making major, custom electronic modification of cars into the hands of everyone. It’s a development that has been more than 12 months of work in the making, and one that I think is enormously exciting. More on this as we get closer to launch.

Books to read

Posted on January 8th, 2009 in books,Ford by Julian Edgar

It’s been said that the victors write history. It’s also the case that history tends to be written in the native language of the country – or company. Perhaps it’s for those reasons that good histories of the major Japanese car makers seem so absent – or, when they do appear, are rather lame.

Honda Motor – the Men, the Management, the Machines was written by Tetsuo Sakiya in 1982. When I came across it, the age of the book didn’t worry me – surely all the foundations of the company were in place by then – so it was a read I was looking forward to.

However, the promise isn’t fulfilled. Basically, it’s because the author feels the necessity to wander off into prolonged diversions on Japanese history, culture, labour practices, emancipation of women, trading companies, the role of government – and God knows what else.

The muffler yell test…

Posted on January 6th, 2009 in Driving Emotion,Mufflers,testing by Julian Edgar

Years ago I did a muffler comparison test for a magazine. I used about $120,000 of equipment to test the sound attenuating properties of the mufflers – including a dyno, test car and sound pressure level meter.

Since I was working from home, I ended up with a lot of mufflers (all clean and brand new, I might add) strewn around the lounge room.

And, in a moment of (drunken?) lunacy, I found a much simpler way of testing the mufflers than using a dyno and the rest of the gear. In short, I simply grabbed a muffler and yelled through it.  And then another muffler, and then another muffler…