The Race to 100 mpg

I just read the article on the race to 100miles per gallon. It is just to bad that you are reporting on engineers and car companies that think they can produce high millage cars ten or fifteen years down the road.That is the same song and dance we heard ten or fifteen years ago. Instead you should be out there beating the bushes looking for the shade tree mechanics that are doing the high milage thing now. The problem as I see it is untill government and the oil companies are made to stand down and let people design, publish,pattent, and market equipment and or systems to get the high milage without burning oil we will never see much better milage than we have now. For God's, sake we had a 1980 VW Rabbit diesel that got 60 miles per gallon religeously. Where is the improvement since then? There hasn't been any thats where. I have in front of me the plans for a hydrogen generaterthat si claimed to run a Caddy V8 useing water as the fluid to seperate to get the hydrogen. The problem he ran into came from the pattent office. He was told by government agents that he would be in more trouble than he could emagine if he tried to produce the system. Other inventers/designers have either been bought out, burned out, or killed to keep their equipment off the market. I know I sound like a conspearicy nut but a guy can only hear just so many cases before you begin to believe there might be some truth to them.

The problem with conspiracy theories and urban legends, is that they feed on themselves and lend themselves apparent credibility, when told often enough or added together.

Myth Busters recently recreated the hydrogen patent you described, and it was summarily busted. Patented devices don't necessarily work, just because they are patented. Patents only last so long, and are all public record, so who is going to stop you or anyone else from recreating them? You think the Russians (in their day) or the Chinese would be intimidated by "Big Oil", and prevented from developing any of these patents, especially once they expire, if they had any real potential? Please. More likely, these stories are concocted by the "inventors" themselves, because the patent is worthless, they can't find any suckers to invest in it, they can't (or more likely won't) invest in it themselves, the period of public disclosure has or will run out, and they wan't to salvage some kind of credibility (yeah, I'm the visionary who invented and holds the patent on the Super Widget, but...).

Why has there been no significant improvement in mileage since your Rabbit? Because there was no perceived need. Fuel costs were considered acceptable by the marketplace. In fact, that's what made the SUV boom economically viable. What there has been is significant improvement in emissions, as mandated by government regulation, spearheaded in California (think L.A. smog, the perceived need).

Now things have changed (fuel prices and CO2), and as a result, so will the marketplace. It's called free enterprise (you know, supply and demand, etc.).

Patience. And give your head a shake.

Munky, How I agree with your views.

Conspiracy theories are not credible when your major manufacturers and ours are spending billions on developments of newer technologies - hydrogen included, although my favourite for the short term is the diesel mild hybrid fuelled with CTL fuel.

It would help however if the US could follow the EU lead and mandate an ever rising "Corporate Fuel econony standard" say 30 mpg next year and rising by 3 mpg per year every year. Just to make it clear that is US gallons since our English gallons are smaller. For comparison my VW Passat 1998 diesel model does 52 mpg (UK) on average including town driving and motorway driving at 75 mph.

That would soon get the unnecessary 4 X 4 and pickups off the road and get us on to proper sized saloons which are much safer for the pedestrians they hit.

Now there is an idea, we could insist that the new EU pedestrian impact regulations apply to all privately owned new vehicles in the US too - How abot that for a challenge to the US image of life.

Hugh Mattos

Chartered Engineer

It should be noted, auto companies with significant domestic(USA) market presence ... Ford, GM, Honda, Hyundai, Kia, Nissan, Suzuki, Toyota, VW, et. al. (and their partners) have 48 (or more) vehicles that achieve better than 44 mpg(US) combined average in Europe. While in the USA, they have only 47 that have a combined average above 30 mpg(US) combined average ... only the Prius, Civic Hybrid, and 2 Yaris get over 35 mpg(US) average. The major difference seems to be the Euro Step IV diesel engines (and Step V and VI are on the way).
Sources:
http://www.40mpg.org/pdfs/021407_fuel_efficient_vehicle_gap.xls
http://www.vcacarfueldata.org.uk/search/
http://www.fueleconomy.gov/feg/byMPG.htm

This appears to translate to almost a 20 mpg or greater mpg advantage for the European models compared to those in the USA. That is a 50%, or higher, mpg availability in their European models. This achievement results in approximately a 120 g/km reduction in CO2 emissions over the currently available "domestic" product. There are a number of these vehicles that are approaching the 60 mpg(US) combined average range (example: Toyota Aygo is rated at about 58 mpg(US) average and 69 mpg(US) highway in the UK with CO₂ emissions at 108 g/km).

Since the designs and production already exist, the only issue is "domestic" emissions management and the solutions ARE being developed and implemented by these very same companies in Europe and Asia TODAY ... ooooh ... yes they (the European portion of these same companies) are complaining ... but they are doing it just the same! That includes emissions, fuel economy, materials, designs ...the whole thing. Keep in mind that Euro Step V and VI emissions standards are on the way, as well as 140 g/km CO₂ in 2008.

Just my observations ....

Any info on car sizes - the general understanding in Europe is that American cars for US market are BIG.

My current vehicle is big by UK standards at 5m long and the 2.5l turbo diesel is above the average engine size. Still does ~37mpg average, and is no slouch.

Am I correct assuming you are using Imperial gallons, ie, ?~ 30 mpg(US) for your vehicle?

In the US "light" vehicles range from about 2,500 to over 8,000 pounds. I would guess the typical machine is in the 3 to 6 thousand pound bracket. If you are in the UK (or Europe), I suspect you laugh when you hear the folks from the USA complain about expensive gasoline at $3/gallon(US). It is just "new" to US ... particularly when a significant number chose (in the past) vehicles that are in the 12 mpg(US) combined average range. Many have opted for large (about 5 m long) SUVs, vans, and pichup trucks for personal use ... ego (or safety fears?) I guess.

My personal vehicles are in the 24 and 38 mpg(US) combined average range. The higher mpg vehicle is a Honda CIVIC 1.5 liter gasoline ... so a 1.5 turbo diesel in a moderately larger 4-6 passenger vehicle would make me very happy. I speculate that would result in about 45 mpg(US) average [54 mpg(Imperial)]. Particularly with the higher low end torque. I just wish we had a vehicle like that here in the USA.

Now, 2 questions ... how do you like the diesel and are there any good websites to study the diesels (and diesel autos) that you can suggest?

Hi,

Good to hear that a US resident is keen to learn about DIESEL. My view is that a diesel car is great, and when CTL technology allows use to use synthetic diesel fuel then all the emissions issues will make diesel the first choice for all users.

I have been in the auto industry all my working life and I would not think of buying a petrol car. I ran a vehicle rental business and ran diesel Peugeot cars to 250000 miles routinely and Mercedes diesel vans to 400000 miles. Just keep changing the oils.

The modern diesels are so much more fun to drive and all the new models with exhaust particulate filters - yes they need a "major service every 72000 miles" emit so much less CO2 than a petrol and in most European cities - I would not presume to claim this for US cities - the exhaust emits less particulates - small dust particles - than it takes in through the intake so the city air ends up cleaner as it passes.

I drive a 4 cylinder 2.0 litre VW Passat - great car and still achieveing an average over the last 3000 miles in excess of 52 miles per Imperial gallon - in town traffic and driving fast. You cannot hear the engine when driving above the noise of the tyres on the road

Our best magazine in England is called DIESEL CAR and they have a website at www.dieselcar.com which gives road tests and data - among softer things.

Hugh Mattos

Thanks for the link to Diesel Cars.

Regarding bio diesel, I am trying to learn about algae agriculture (algaeculture?) as as feed stock sources for bio diesel. Apparently it can scub about 80% of the CO₂ from industrial combustion during day light hours ... in effect removing and recycling it into bio fuel feed. That equates to about 40% CO₂ removal on an annual basis.

It is claimed that a 1 megawatt gas fired facility can generate 32,000 gallon(US) of bio diesel and of 20,000 gallon(US) ethanol per year on less than 6 acres. A coal fired facitity is expected to be able to generate about three (3) times that amount (due to greater CO₂ output) per year but requires about 18 acres.

These numbers are significantly better (approximately X10) than traditional palm oil at 700 to 900 gallons per acre year.

This one's the first multi-valve TD - excellent performance, sometimes too fast! (Lots of speed cameras about, so need to be very gentle with the right foot). Acceleration is about the same as a 2.5l petrol (without turbo).

I have driven 1.4l diesels, but noted that they did not have the same power advantage of the 1.7l+ diesels. This may be due to their recent development, as larger diesels have been around for much longer.

The 1.4l car weighed in at 795kg, the 2.5's at ~1400kg.

Considering the payload difference - 450kg/1.4l & 1000kg/2.5l - and the fact that the smaller car drank lots more when full while the larger ones do not seem to notice the weight, I would not reccommend using a car with an engine smaller than 1.7l if it is filled regularly.

GM1964,

It is all " Horses for courses" We have a Peugeot 1500cc non turbo diesel and it is still fast, but acceleration is slower and it does notice the load if we have four aboard, however it is great for my learner driver son and the fuel economy is over 60 miles per imperial gallon

On the other hand the GM Vauxhall Omega we had was a real luxury automatic cruiser. Big - by European standards - and comfortable and still over 40 miles per Imperial Gallon

I think it is noticeable that all our police forces use diesl cars and even the fast response cars are moving to diesel. -

All you sceptics out there should drive one for a week and be converted. Hence diesel cars account for 30% of all new cars in England and 50% over the whole of Europe where the green parties have more influence on policy.

Hugh Mattos

Chartered Engineer

Hugh,

The US gallon is approx 3.7 litres and the Imperial gallon 4.5 litres.

America is suffering from the high cost of gas ? I am (almost) speechless.

At least the Terminator has converted both his Hummers , so progress is happening.

a few years ago i had an employee who had a brother working for gm and his brother told us that some guy had invented a carburator that could get 200 MILES A GALLON.

thats right you guessed it right, the oil companies bought it and all the paper work he had on it. i guess if he had not sold out he would either be filty rich or just dead.

" those that say it can`t be done, should get out of the way of those doing it."

This sounds a bit anecdotal to me !

We use fuel injection now as carburettors cannot deliver fuel accurately enough for fuel economy or emissions.

Hugh Mattos

Chartered Engineer

Toolman521 has a point , where's the motivation for major car manufacturers. Cars don't sell on a green image. One of my brothers (fairly high flying social psychologist ) was engaged by a leading US maker to help look at the effect of 'greening-up' their image. It was more an exercise in damage limitation.The sound of a gutsy engine outweighs social issues.

How many injections/power stroke is considered best production practice these days ... if you know?

HughMattos quotes the use of fuel injection - but a more recent addition to the kit of parts giving the very good economy from European Diesel cars is the new generation of variable geometry turbochargers. For each load and speed demanded by the vehicle, only the correct airflow is delivered, and this means good fuel economy and very low emissions.

The "Big Three" all came out with concept cars in 2000 that averaged over 70 mpg....What's the problem you ask...They were diesels...Opel has a race car that can do 155 mph and get 125 mpg doing it....Over half of the cars now sold in Europe are diesel...Diesel is definitely the way to go, we just have to reduce the particulate emissions...This can be done, in part, with cleaner burning biofuels....Be sure to check out the new Humvee diesel hybrid the US armed forces are developing...The Shadow...

The Toyota Aygo 1.4 D-4D 3 & 5 door diesel is about 55 mpg(US) combined average with CO2 at 108 g/km. This vehicle is Euro Step IV emission, but I don't know if it includes a particle filter.

Here is a reliable source: http://www.vcacarfueldata.org.uk/search/

Another interest prototype is the DiamlerBenz "Bionic Car" also called the "Box FISH" that is a 140 hp diesel that is suppose to get 70 mpg(US) combined average, If I remember correctly, 0-60 mph was under 8.6 seconds.

I have been interested in cars since I was a kid. Now at 77 I have seen a lot of stories. I remember my Dad saying when he bought a new 100HP Ford that it would go up Red Rock hill in 3rd, who would ever need more that. But back to the chase, we have a local car agency lauding the Corvette 24 mpg and a top speed of 178 mph. just what I need on NC roads with the State Police watching over you. As an engineer I know the stories of the 200 mpg carburetors are not true the laws of thermodynamics won't bend that far. Our problem is the weight of the tanks now being sold as cars and the exhorbitant engines being installed that at road speed of 70 mph just idle along at 2500 RPM. Back in the old days around 1945 a couple of URI electrical engineers designed a car that was small, a 2 seater that you would drive to work 40/50 miles, when you get there, either start the small generator or plug into 110V power (see the smoke from the power plant). It utilized the braking of the motor to charge the batteries also. I owned a Mazda diesel pickup, I had to have a pickup, I live in NC, I loved it and it ran like a top, I sold it after 250,000 miles. I have made a lot of mistakes in my life.

Finally, look at Bombadier (Canada) and what they did with the Evenvrude and Johnson outboard engines, from a failed design they reengineered the finest outboards on the market with a warranty twice what most give. The US goverment has given the auto industry millions of dollars for research and we have seen little from it.

Good to hear that you too think that Evinrude Direct piezzoelectric injection two strokes are the finest engines.

We use them on our boats - see www.explorermarine.co.uk - and I really enjoy them.

Hugh Mattos

Chartered engineer

The main problem with 2 cycles in the past was the positioning of the valves (ports), they had be positioned artbitrarily to cover low and high rpm.

Evinrude (sorry for the misspelling) overcame this with the control of the injection by piezzoelectric injection.

I worked for a number of years for Homelite, Division of Textron they manufactured 2 cycle driven pumps, generators and chain saws. During WWII they made thousands of generators to start the engines of the bombers flying from England to Germany. On the way home and shot up the first thing jetisoned to lighten the plane was the generator.

Unfortunately they went into the outboard engine business just when HP was going up. we had a 35HP 4 cycle which was upgraded to 55HP, after 16 million dollars it was dropped.

The reference to Evinrude and Johnson is quite interesting as their injection technology comes from Orbital Engine Company of Perth Western Australia. Aprilia also use the technology and many other engine manufacturers took up preliminary licencing but haven't followed through. The Australian subsidiary of GM spent millions trying to defeat the Sarich (now Orbital) patents, when they couldn't use it for free GM did everything possible to prevent adoption, (they are used to getting Australian technology for nix). This one isn't an urban legend, Evinrude and Aprilia and several Indian manufacturers are doing well with Ralph Sarich's inventions. The problem was although the Sarich patents allowed 2006 California emission standards to be easily met in 1990, using the technology would have precluded the application of massive subsidies and would have alienated their oil company interests.

The failure to adopt known European and Japanese diesel technology is driven by the same motives.

Engineers can always come up with ways to meet legislation, its the company accountants who want everything done one small step at a time - the "disposable" cars of the 70s with little or no rust protection have been rejected by the masses as they want a return on their investment, so other methods are now used to stimulate the desire for a new vehicle. Gradually increasing spec. has resulted in every conceivable device being "standard" in top of the range models - the only way left to go is "green", so this will be done as gradually as possible so that the customers keep coming.

Yes it all must be a very gradual process otherwise the employees at the factory making the "older" technology are all out of a job rather unexpectedly. And further afield far worse consequences arise.

Car designs have a rolling lifecycle of updates and replacements, but there are good signs that even the big boys in America are slowly moving towards diesel and even some better hybrid technologies are on the move into the showrooms.

Think what would have happened if some EU or US politicians had mandated the green solution of ethanol based fuels? The price of US Maize this year is already double the price last year. None will be surplus for gift Aid to Africa, so millions will starve because they are too poor to buy at the higher world price.

What percentage of US fuel is ethanol or methanol based?

All engineering solutions have consequences.

Hugh Mattos

Chartered engineer

Ethanol in the USA is a frustrating infuriating puzzling mess.

Demand (and price) for corn/maze is out of sight and we have millions of ethanol capable cars on the road. We have E85 (85% ethanol and 15% gasoline) plus some special low percentage ethanol "blends" for regional seasonable pollution management ... sounds impressive!

Guess what ... E85 is sold at less than 2,000 service stations (retail distribution facilities) in the ENTIRE COUNTY!!!

The story gets better.

The ethanol flex fuel vehicles were built and sold (with no known E85 fuel supply available) to circumvent Federally mandated increases in fuel economy. You can guess how it is with some business types, lawyers, and politicians when there is a possibility of legal loopholes.

AS an engineer, American, and human being, I am embarrassed. Sorry WORLD ... sometimes we don't used common sense and good judgement!

By the way, this started under Bush senior.

Oh dear,

I thought Jack Boot Johnny (little john howard) was completely behind your mob refusing to mandate 5% ethanol (E85 and all that), turns out another case of Bush, Shrub and Bonsai in lock step. Effing terriffic.

Hugh,

Pull out your "Odds and Sods" album and select "Now I'm a Farmer". Pete Townsend (the genius) will capably explain why there is no shortage crisis, just another political one.

So so well put GM1964.

GM1964 and Emjay4119, would you agree that the auto industry strategy of "a little bit at a time" and the awareness of the consumer of that strategy may be a significant part of the auto industry down turn (particulary in the USA)?

US and US subsidiaries definitely yes! The Australian car industry was taken over by the US in 1948 when the 48_215 was released (1948 / 2.15 litres) by General Motors who took over their Australian body builder Holdens body works.

I have a saying, that maybe you'd like to think about. The motor car was invented by the Germans (Benz), the mass produced car was produced by the Americans (Ford), the Quality mass produced car was produced by Japan (Toyota).

US interests have relied on cheap energy, wages, and cheap piracy of foriegn patents to fool their gullible public. Lets face it most SUV owners (known here as SOFTROADERS) think Henry Ford somehow invented and produced and marketed transportation without the need for venture capital or the existance of an established business model.

Definitely true!

In the UK, our car/truck manufacturing in the 70s basically tried to stem the flow of imports - both from Japan and the Eastern Bloc (Lada) - by the "Buy British" campaign (including British built Fords & Vauxhalls[GM]). This involved burying their heads in the sand where progress was concerned.

In the mid 80s, I was driving a Ford Cargo (built over 2 years before it saw the road), which could hold 3½ tonnes of load, and took 100l of diesel for the 350mile daily round trip. This was replaced by a Volvo, with Turbo (and full winter gear), 8 tonne payload and used just 5l more on the journey.

The EU has a rolling program of engine improvements, and Volvo continually announces their vehicles to be compliant with the NEXT standard, as soon as one comes into force. Needless to say, many more Volvos on our roads compared with home produced.

GM1964,

Yes I too have watched the demise of the British Commercial Vehicle industry. Having worked for Bedford trucks, and then briefly for IVECO / FIAT when they bought Ford Trucks.

It all makes me too grumpy, and has little to do with a 100 mpg vehicle, so I will let that issue sleep!

Hugh Mattos

Chartered engineer

I hope it wasn't you who designed the power steering for them!

The earlier versions without had a reasonable turning circle - even if it did take Charles Atlas. Once power steering was introduced, three-point turns were mandatory at almost every junction in town.

That is something Leyland DAF were good at - the "roadrunner" (latterly DAF45) could be turned lock-to-lock with only one finger!

GM1964,

Did you have experience on the Bedford Truck steering or the Ford Cargo (?) steering..?

HM

I've driven them all!

The point I was trying to make was that where the company perceives no problem, no solution is sought. The first power steering in Bedfords was obviously an afterthought - probably sales turned round and said "we can sell 50 trucks next week, but they must have power steering" - no time to design it in, just add it on.

The whole of the UK motor industry - with the occasional exception - has been this way, and I guess the US is at best the same.

In one night I drove two vehicles the same age - outward trip was a Scania with a 12speed gearbox and preselect on the planetary. It drove like a racing car, with very slick changes.

The return trip was a nightmare - a Ford Cargo with an "eight" speed box. This took so long to change ratios - double-declutching in between - that 4th and 5th gears were the same ratio!

No doubt Ford thought that no-one would buy strange foreign trucks.

The 100mpg car will only appear (mass produced) when either the public demand this, or legislation is introduced to make it happen.

As it happens I was responsible for Bedford Truck steering for a while from 1983 to 1987, however that was as a reliability engineer not a design engineer.

At that time we used Bendix Iberia steering boxes which were settable by the dealer, but few dealers had the confidence to touch them.

As ever, the accountants were the problem as they would save £5 per truck whenever possible even if it reduced the perceived value to th customer. Also Bedford was always the budget brand - the basic solid easy fix truck - whereas Volvo and Scania were the premium brands.

As today, I can pay a lot extra for the Mercedes or BMW car, but I may be satisfied with the Ford or Citroen at 60% of the price.

HM

"save £5 per truck whenever possible even if it reduced the perceived value to the customer"

Spot on! This "perceived value" is where the problems lie - can the company anticipate what the customer will accept, and will they wait until improvements are demanded - or the industry norm - before introducing added value. Obviously there is a risk of taking early introduction too fast - look what mass producing fwd in 1934 did to Citroen (bought over by Michelin).

With Bedford, the components were reliable, but did not work together efficiently to improve the driving experience - When drivers take longer to negotiate obstacles, this is noticed in their productivity - at least 20% less with a TL than a roadrunner on multidrop.

Primary cost and maintenance are only part of the equation.

I believe you both have described the environment as perceived by the primary auto makers very well (including here in the US) ... "as long as they will buy it why improve it [but maybe we can cost reduce it], besides look how many potential consumers watch racing every week".

Here in the US, it seems that the purpose of a car is no longer transport with reasonable economy and comfort ... it seems to be ALL EGO and how much electronic "entertainment stuff" can we get the buyer to pay for.

We have digressed from "The Race to 100 mpg", the point of the thread.

It occurred to me that to achieve "100 mpg" requires about (or less than) 200 W-hr/mile or 2 litres/100km. It appears that this rate of energy consumption would put the engine power in the range of 9 hp.

Does that sound correct?

If it is correct, then, this will play hobbs with accelleration without a mild hybrid at minimum. I would guess this brings us back to either the electric or hydraulic hybrid ... unless someone knows another option. Any ideas?

Fiat have a "new" idea:

http://www.autoexpress.co.uk/news/autoexpressnews/203783/fiat_500.html

Back to basics with just 2 cylinders - but you CAN have a turbo!

I wonder what the figures will be for this.

The original Citroen 2CV had 9hp from a 400ish cc engine (flat twin air cooled) and got 55mpg - in 1948. Applying modern techniques - vvt, turbo... - could be the way ahead - if the powers that be had not deemed air cooled as too niosy.

http://www.conceptcarz.com/vehicle/z7530/Citroen_2CV/default.aspx

The only other way they will arrive, will be if the Japanese (or Continental)manufacturers decide to steal a march on the hidebound opposition, again.

A clear and recent illustration of this way of thinking is easy to see in Australia where two of the local manufacturers are Japanese owned (Toyota and Mitsubishi) anfd the locally made 6 cylinders from these factories are a joy to drive. The Ford Falcon is reasonable, but course by comparison, and the Holden (GM) is an absolute dog. The American companies use motor racing to sell and have successfully kept the other local builders out of the competition for many years.

But I really think you have hit it on the head, emission controls were not voluntary, and the initial attempts were so poor they looked like a comspiracy. Safety also had to be mandated by government in response to consumer backlash (take a bow Ralph Nader). More recently Mining Companies such as BMA are laying down the law about how a vehicle must be fitted out for safety (fatal risk protocols), already this stance has saved lives

Can anybody recommend a good comparative web site for this issue. How much does it cost to deliver power at the axle for diesel/petrol/electric/etc. I appreciate that this is an oblique question , but years ago I was in South Africa and somebody rattled a spokesman for Sasol ( coal to oil people ) by asking how much energy was expended to create 'x' amount of petrol energy from 'y' amount of coal energy. Obviously he didn't get an answer.

What kind of fuel is diesel? It seems that much work in the USA has been put into the fuel sources, moving away from "fossil" fuels, in addition to increasing mpg. I'm not a fan of hybrids. In addition, sources that would require a new infrastructure for fueling would be hard to market. There's an interesting chapter in Robert Ehrlich's book "Nine Crazy Ideas in Science", which posits that so-called fossil fuels are actually renewable.

I also recall several years ago seeing a story on a car that would run on methane using the existing engine. It was my understanding that methane occurs naturally from decaying matter. This is why you'll usually see a big open flame at dump sights; they are burning off methane.

The first thing about diesel in the USA is the implementation of Ultra Low Sulfur Diesel (ULSD) in summer 2006 (done years before in Europe & most of Asia) that reduces sulfur in diesel fuel (for on road use by 95%). It can be contaminated by other fuel residues (heating and off road fuels). Protocols/procedures have been establish to control this problem. Diesel has the highest energy content ... above 130 kBtu/gallon(US).

Bio diesel would have to be tanker (dedicated) transported for the foreseeable future.

Ethanol is even more sensitive and is hygroscopic which makes it significantly more difficult to handle and deliver. E85 would have to be tanker (dedicated) transported for the foreseeable future.

I agree with you that electric hybrid is not my first choice either, GO DIESEL (ready for bio diesel)!

Well said Sir,

I have run a small vehicle hire firm and the last 150 vehicles we have purchased have all been diesels. I cannot see us buying a petrol car again.

That said I would thoroughly support the diesel microhybrid as the ability to boost power allows a smaller diesel, and the ability to drive a short distance on electric only allows the diesel to switch off in heavy traffic - and of course we could drive to the corner shop without a pang of conscience.

Then, like mobile phones, as the batteries get better we can drive further without starting the cold engine. Then as the solar panel efficiencies rise we can charge the new batteries with a roof panel photovoltaic system

Hugh Mattos

Chartered Engineer

Hugh we still agree.

For your amusement (or frustration as appropriate):

The Prius requires about 0.4 kilowatt hours per mile of travel. Then GM's "VOLT" is expected to be the same but has a 16 kw-hours battery pack to support 40 mile runs on electric. Then GM's says the plan for the "VOLT" is to load the vehicle down with collision avoidance and autopilot systems along with the traditional entertainment electronic ... you see where this is going. Just keep in mind that a cell phone probably consumes about 4 watts when active ... do you believe the design Will get 40 miles on a charge or the rated mpg?

I thought you might be amused by the madness of our "domestic" business types.

The solar collector sounds good but I wonder if a 4 square meter collector could fit on the roof and bonnet (I hope that is the right word) of one of these cars and what level of energy could be recovered? If I remember correctly peak solar power is about 900 watts per square meter. If we assume 25% (I believe this is high) over 8 hours, that results in 7.2 kilowatt hours of energy/day or less. That would help ... but production costs would have to come way down for it to become cost effective.

The Prius was designed with economy in mind - and so has as few unneccessary gadgets as possible, and those which are fitted are the latest, low energy designs (and as such are expensive).

The GM "VOLT" has been designed for the US market at present, which "demands" all mod cons - video, aircon, etc, etc.....and as such may indeed struggle to have a 40mile range on batteries alone - sufficient for the school run?

With these hybrids, the driver has a much greater effect on fuel consumption/range - I can here it now - "Shut that X-box off or we'll never reach home!!"

Of course, the solar panels could be used to recharge the auxiliary battery to keep the kids happy (while they're waiting for the tow truck).

Yes as you say costs will have to come down. Solar conversion of 25% is some way away, however, the 40 mile range is more than many drivers do each day in the cities, on the way to work or school.

The main issue for me is the ability to crawl in traffic as so many do, without the diesel running, and to eliminate the engine on the very short trips - less than 5 miles - when the diesel will be very cold and therefore very dirty.

Hugh Mattos Chartered Engineer

The VOLT 16 kwh battery pack is said to weight about 167 kg. The problem I have with electric is that my better half likes A/C about 20% of the time ... we live in relatively warm climate (particularly with solar gain). It is my guess that A/C is a minimum 200W load on the electrical system.

I guess I'm relatively lucky living in a "rural" area ... very little traffic congestion, but on the down side it is about 6 km to the nearest shopping.

There are about 8 traffic light with greater than a 2 minute cycle time within my primary driving area. I guess "off on stop/start on go" engine would save a little, but it sound like this is generally not available with diesels.

I was under the impression that the newest diesel engines were designed to minimumize cold start "dirty emissions".

Is this still an issue on the latest designs or is it just manufacturer depependent?

Which car manufacturers have the cleanest and best high mpg diesels?

All petrol and diesel engines are pretty dirty on startup - first 30 seconds, and most are pretty poor for the first 5 minutes - compare the cold start performance with the highway figures.

HM

Understood! The Chinese had a report on real "instantaneous" time instu emissions on a population of vehicle types. The data was pre 2003 ... if I remember correctly. Cold start was not good ... more than an order of magnitude if memory is correct.

I was hoping that some of the recent work with combustion management had made it into the market ... well ... 2008 I hope.

Yes some of the work which Mercedes and BMW are doing - together which is unusual - is aimed at trapping and holding the particulates trapped in a urea fluid catalyser. I think PSA group have a similar system.

The idea is that the catalyser cleans itself when it is hot but the pollution is trapped until that time. Some schemes even inject extra fuel so that it passes through the engine to burn off the soot on he catalyser core. Saves a good deal on emissions, but like all these systems makes the overall energy conversion efficiency slighty worse!

Hugh Mattos

I preferred the older "wasted spark" system, where twin coils were used instead of a distributer and each end attached to a spark plug, the spark during the exhaust stroke cleaned the emmissions up without using a cat. Only worked on petrol motors, though.