Response

Front Spoilers

I was very impressed by the great level of science displayed in your Real World Spoiler Development article. As a matter of interest, before I read this article I had done some experiments of my own on my old 89 Honda Accord. My first Air Dam was made of a thick rubber. I tested vertical and at an angle with the bottom further forward. I was testing for down force by handling feel (very crude) and for drag measured in coasting distances and MPG. I found very similar data. I could feel no difference and estimated about 4% less drag. However, I then tried bending the rubber into a rounded shape as the front of a bubble. Once that was accomplished I boosted MPG up to an average of 13% via creating less drag. You may want to try bending your aluminum air dam to help guild the air by giving it somewhere to go. I believe your data would support my theory.

Brett

United States

NSU Ro 80

NSU Ro80 - I used to own one in the UK!

I still like the look of the Ro80. It is elegant. But when you get up close to them now (there are always a few at car shows in Canberra each year), all the peripheral stuff looks very old fashioned (which of course it is!). The wing mirrors, the windscreen wipers, the dashboard (a big slab of a thing), the steering wheel (huge, with a rim about as thick as a wire coat hanger!), and lots more.

The engine was run under all manner of conditions for very long amounts of time by the NSU engineers prior to the car being launched, and they were genuinely caught-out (as I understand it) by the almost immediate engine failures displayed in the cars sold to the public. The mistakes that the engineers made were (a) not giving enough consideration to cold starts - the time of maximum wear and (b) not employing a rev limiting device (not even the buzzer that Mazda used), and people really rather stupidly just treated the engines as though they were indestructible.

The first cars were released in 1967. My car was a 1969, I looked after it, drove it in a sympathetic way when it was cold, and rarely felt the need to rev the nuts off of it. It still had the contact breaker and two spark plug engine, going to electronic ignition and one plug was NSU's first major change, but despite being one of the "duds" my car had done 70,000+ miles when I left for Australia in 1979, and such was the car's reputation that I had to almost give it away.

It did have starting problems in winter, the spark timing was absolutely crucial. You could not rely on the NSU dealerships to get anything right, and of course nobody else wanted to open the bonnet. I very soon learned how to look after it myself.

For me the very worst thing was the gearbox. Three forward speeds, through a torque converter, no clutch pedal, and a clutch operated via a micro switch under a wobbly gear lever knob. This gave the driver no control whatever over the clutch, the electric switch meant the clutch was in or out. And the penalty of a torque converter when the car didn't change gears for itself. The very last year of production (1977) saw it fitted with the automatic gearbox it should have always had.

It did chew up petrol around town (about 17 litres / 100 kms - ouch). It did roll a lot in corners (like a boat!), and yet it felt very secure to the driver. It was slow off the line, but on a motorway it was wonderful - effortless, quiet, comfortable, while returning not at all bad fuel consumption. I once went from Ramsgate in Kent to Newcastle-on-Tyne (very close to Scotland) and back in a day (don't ask!). According to Google, this is 453 kms each way as the crow flies, so presumably a good deal further by road. Motorway very nearly all the way. I got 33 MPG (that's 8.56 litres/100 kms!) that day. And that included 60 minutes at (a highly illegal) 100 MPH. I was bored, it seemed like a good idea. Coming back to the speed limit of 70 MPH after an hour was the downer!

The Wankel rotary is dubious in a car, and should never have been put in a motorbike. In an application where the engine is started, then a throttle opening is set and left (aircraft, boats, snowmobiles, chain saws, etc), the poor fuel economy, poor torque and poor emissions can be engineered-out, and since the rotor tip wear was long ago fixed, all the small and light and smooth and few moving parts benefits are allowed to come to the fore.

The Ro80 was certainly a car before its time. Hindsight probably says that NSU were wrong in not offering the brilliant car with a conventional engine as an each-way bet - Mazda had that covered with considerably less than brilliant car designs, and they are still around, and still persevering with the Wankel design too.

Barry dal Herbert

Australia

Well to Wheel of Electric Cars

I was just reading an old article called Alternative Cars, Part 1 Electric. The article was generally good, but I've found a few omissions which, unfortunately, means that electric cars aren't as good as the writer thought.

The writer states that electricity generation is very efficient. Unfortunately, this isn't quite correct... A CSIRO paper states that brown coal (ie: Victorian power generation) conversion efficiency is 27% (http://users.bigpond.net.au/Bioenergyaustralia/Reports/csiroc02.htm).

In addition to this, the power distribution network is generally around 35% efficient. When the efficiency of the car's batteries, electric motor, etc is taken into account (totalling approximately 50%), electric cars (from the power station to the wheel) is around 4.7% efficient. Adding in the effect of mining and transporting the brown coal, this comes down to around 4.6% efficient. Adding in regenerative braking will increase the efficiency to around 6.9%. Brown coal emits around 93000 tonnes of CO2 per Petajoule of heat, leading to 1.35 kg of total CO2 emission per Megajoule of energy at an electric car's wheels.

A typical small car is around 10% to 15% efficient. The CO2 emissions prior to petrol going into a car's fuel tank is around 15% - 20% of that of the fuel's lifecycle emissions (http://www.nrc.nl/redactie/Europa/milieudefensie.pdf).

Without going into the theory, this means that the energy used in producing petrol (from the well to the fuel pump) is approximately 20% of the energy value of the fuel - ie: extraction, refining, and transportation of petroleum fuel is 80% to 85% efficient. This means that the "well to wheel" efficiency of a small car is around 8.0% to 12.7% efficient (more for hybrids). The information in the above link states that the CO2 emisson of liquid petroleum fuel (petrol, diesel, kerosene, oil) is approximately 2.5 kg per litre. The actual value (from detailed chemical and thermodynamic analysis) for petrol is 2.285 kg of CO2 per litre of petrol, which equates to 0.066 kg of CO2 per Megajoule. When the above efficiencies are put into the equation, this results in 0.52 kg to 0.825 kg of CO2 per Megajoule of energy at the car's wheels.

All up, this means that where the electricity supply comes from non-renewable sources, using an electric car will result in up to 2.5 times the CO2 emission of a similarly sized petrol car.

However, in defence of the electric car, once we have high enough percentage renewable energy, the use of an electric car will result in up to 100% reduction of CO2 emissions. In other words, the electric car is only as good as the electricity generation system that provides its energy.

I trust that this information proves to be informative.

Danny Barrett

Australia

As you have said, the energy efficiency of an electric car primarily depends on how the electricity is generated. Assessing the Alternatives is - we think - the definitive article on the topic.

Lighter Commodore

They're making the Commodore lighter: http://www.drive.com.au/Editorial/ArticleDetail.aspx?ArticleID=56210&vf=2&IsPgd=0

About bloody time.

Ash

Australia

Water Injection

With energy on (what appears to be a never ending) increase and as the owner of a VW turbo diesel automobile and an "over the road" Volvo powered tractor trailer vehicle, I found it interesting to read your article about water injection systems. In an never ending quest to improve my fuel mileage, I too have wondered if water injection would be feasable. May I refer you to a couple of websites I've discovered that made clear any doubts that I had. They are; Aquamist.com located in the UK and the other is Snowperformance.com located here in the USA. Horefully they will answer questions and doubts that you have. I purchased a (damnably expensive) Snow kit and am in the process of acquiring a suitable tank to be mounted a midship behind the cab of my Volvo truck. Because of the corrosive nature of the water/methanol mix I will be using, I need a tank made of stainless steel with a capacity of 60 to 70 gallons. Again, very expensive. To affirm to what you made have heard (or read) about the weather here on the desert floor in Phoenix,Arizona..........it is hot, oh boy is it hot here!

Ray

United States

We’re interested to see how you get on with the truck.

Did you enjoy this article?

Please consider supporting AutoSpeed with a small contribution. More Info...

Share this Article:

Tweet