Motors - Eco-Cars & The Ordinary Alternative

Eco Cars & The Ordinary Alternative 

 

One of the key considerations behind buying any car today is not it’s standard kit list, how it looks, or how fast it is, it’s simply how miles does it do to the gallon and how much is the tax?

These are worthy considerations. While motoring isn’t the out-and-out planet killer car-hating groups will tell you, cars do indeed contribute to the CO₂ emissions of each country of the world and the lower these emissions are, the better off we all can be, in more ways than just our wallet. This has brought on a raft of so-called ‘eco-cars’, cars that have super low emissions and are more often then not a form of ‘alternate fuel’. However only one little Japanese car manufacturer has put it’s thinking cap on and here’s why.

Toyota Prius - Petrol/Electric Hybrid

2010 Toyota Prius

I was never much of a fan of this car. Because this car, particularly the early versions, is an absolute con. Don’t get me wrong, the technology in it is amazing and the system is a fantastic idea, the system is, in principle, a sound idea but the problem is, it doesn’t scale down to ordinary cars. The Prius is a principle example of how the Hybrid system doesn’t scale.

The problem is there is so little space for batteries and what batteries there are, hold so little capacity, you can only get around 30 miles before your petrol engine has to take over the work load. So it means even a daily commute and school run could require the petrol engines assistance. The Hybrid model is simply proof that the electric car isn’t ready yet. Batteries simply don’t have enough capacity.

My other beef is ‘comparative MPG’ figures. The current Toyota Prius has MPG figures of 72.4 mpg on the Combined cycle. Sounds great? Well yes, but that’s for the electric motor, not the petrol engine. At that point, what you have is a heavy car, being towed by an engine that is rather weedy, particularly with the old 1.5 litre engine. It means the engine has to work hard to accelerate the car, the mpg figures dive.

There are some excellent Hybrid’s out there. The Porsche Panamera Hybrid is a clever system as it uses the strengths of the electric motor; torque. The motor is setup to propel the car from stationary up to 37mph, at which point, the petrol V6 clutches in seamlessly and takes over. Why? Well the initial acceleration is where an engine is struggling the most, it’s as far away from it’s peak torque as it can get and so is extremely inefficient.

An electric motor hits peak torque from zero revs. So it is used the get the car moving, and the engine does the rest with its far more flexible nature, such as multiple gears, which makes it more suitable for higher speeds. The other problem, is the weight of all this equipment. On top of your petrol engine and fuel tank, you need an electric motor strong enough to move several tons, and enough batteries to power it.

The motor may be a lot lighter than the engine, but that doesn’t mean it is particularly light, and as for the batteries... Not only do battery cells weigh an enormous amount, the amount of material that must be mined to obtain the exotic metals for them means that there is a huge amount of embodied energy in Hybrid cars and that while the user is making environmental savings, the manufacturer is in fact doing more damage.

Vauxhall Ampera - Range Extender

2012 Vauxhall Ampera

This is another petrol/electric Hybrid, but one that has a significant difference that is worthy of mention. Like the Prius, the Ampera has a petrol engine and an electric motor, however the petrol engine has no connection to the wheels. The electric motor does all the driving.

So what does the engine get to do? It has been relegated to the job of generator. It simply sits there turning a large capacity alternator, making electricity for the batteries. If the electric motor is really going for it, the engine speeds up, generating electricity faster to keep up.

The advantage is the mpg figures aren’t so wildly different across the range of drives, but like a dual-drive hybrid, if you run of juice, you have to sit and wait for the foul, horrid petrol engine to bail you out. A little ironic for a car marketed on it's alternative fuel credentials.

Nissan Leaf - Electric Car

2012 Nissan Leaf

The Nissan Leaf is the first real attempt at a mainstream production electric car. And it is a beautifully designed car, with nothing to really make it stand out as an alternate fuel car and a fantastically well built car to boot. Nissan realised the average person doesn’t want to be a Save-The-Planet advert, they just want a car.

Because this has been designed to be an electric car, it has been given a far more powerful motor. While the Prius has to make do with 80 bhp and 153 lb/ft in it’s electric motor, the Leaf has 107 bhp and 207 lb/ft motor. While 20 bhp and 50 lb/ft of torque may not sound like a lot, trust me, it is.

The Leaf also has a proper capacity in it’s batteries. While the Prius can manage 30 miles in electric only trim, the Leaf can, and will, do 100 miles. Three times the distance with a propulsion system that is up to the job of moving the car fast enough to keep up with traffic.

The downside? That’s easy. If your petrol or diesel car is running low on fuel, ten minutes after pulling into a petrol station, you have a full tank. The Leaf, on the other hand, will require at least 7 hours of mains electricity. And where does this electricity come from? That’s right, the coal/oil/gas fueled power station. So much for ‘emission free’ motoring.

Honda FCX-Clarity - Hydrogen/Electric

Honda's FCX Clarity

Let’s consider for a moment that electric and petrol/electric hybrids are just a fill in, a support band, for the real future. Is hydrogen power the answer?

On paper, maybe. The set-up is basically the same as any current range-extender hybrid, and like the range-extender it has a fuel tank like any ordinary car, but the difference is what you put in it.

Water is a mixture of hydrogen and oxygen. On their own, these are two substances that burn rather nicely Mixing these two materials, Hydrogen from the ‘fuel’ tank and oxygen from the air generates electricity for the standard faire battery and electric motor setup.

The Hydrogen is obtained using the reverse process that the FCX Clarity uses to generate it's electricity, in an energy intensive process called ‘cracking’ where Honda split water into Hydrogen and Oxygen and use the Hydrogen as a fuel.

And it works very well. The car looks and drives like an ordinary car, while emitting nothing more than water. So what’s the catch? Yes, the ‘cracking’ process, which requires a vast amount of energy to carry out.

So far then, we’ve managed to pick some massive practical and environmental holes in the so called ‘green cars’. But this isn’t to say that these systems will never be perfected, and there is little doubt that the combustion engine’s days are numbered and one of these drive systems is likely to take it’s place.

With the car and computer industry both with vested interest in batteries, the capacity is rocketing upwards and charge times are falling, while Renault are leading the innovation of quick swap systems of replacing your discharged batteries with fresh ones, currently a half-hour process. Not bad when compared to the 7-12 hours required to charge them yourself.

And BMW have recently announced plans for an electric car about the size of a MINI that will have the option of a micro-generator. The idea of using one of the high efficient and high torque yet extremely lightweight, single cylinder motorcycle engines BMW have at their disposal would make total sense.

But these systems are not perfected and, today, are a long way from ousting the petrol engine. And this means that while most manufacturers are jumping on the Hybrid band wagon, they are ignoring the true innovative petrol engines they have developed.

DieSotto Engine

The DieSotto 1.8 Engine

This is perhaps the most innovative system that I have ever heard of. Mercedes Benz developed it in 2007 for the Frankfurt Motorshow as part of the F700 concept car.

The concept was a preview for the new S-Class model, but featured a Twin Turbo charged, 1.8 litre four cylinder engine. However, it featured the ability to self-ignite petrol in the exact same way a Diesel engine functions, using turbo injection with a super high compression ratio to induce the fuel to ignite without the use of a spark plug. This meant that this tiny little engine generated 235 bhp and a massive 295 lb/ft of torque, placing the F700 concept on a par on performance with a S350, a 307 bhp 3.5l petrol V6.

The engine was even better than simply having a high compression ratio. It featured a lot of technology that ordinary cars now come with, such as a start/stop system, a single alternator/starter motor, direct injection, variable valve timing and variable geometry turbos.

F700 Concept Car

However, even this tech pales in comparison to the real achievements of this engine. Firstly, that self ignition system, known as Homogeneous Charge Compression Ignition (HCCI), meant the 2 ton, 5 meter long S-Class could achieve 47 mpg Combined. When you compare that to the 27 mpg for the S350 model, this shows how much potential the engine has.

Not only that, Mercedes engineers gave the car a variable compression ratio and a computer control system that could disengage the spark plugs. Yes, not only could this Petrol engine pretend it was a Diesel with all the advantages of torque and efficiency, it could be a high power, high performance petrol engine, thus making it perhaps the most exciting engine ever created.

But instead, Mercedes admitted they dropped the rather expensive research and development of this engine to develop a hybrid petrol/electric unit due to the much cheaper costs and easier marketing.

I mentioned right at the start about the little Japanese company that can. So who am I talking about? Well, it’s those flogging-a-dead-horse, Wankel rotary lovers; Mazda.

The SkyActiv Program

Mazda love to follow a dead-end route. The Wankel rotary, the engine that started out life as a Supercarger, has never been efficient enough or reliable enough to be a dependable car engine, and yet Mazda refuse to give in and are still determined to develop yet another version to meet ever-tightening emissions. But that isn’t what I want to talk about. No, I want to talk about Mazda’s ‘SkyActiv’ program.

The SkyActiv program is a new step in the design of engines, gearboxes and even body shells, to reduce weight, improve engine consumption, minimise costs and improve packaging.

The Chassis:

The biggest culprit of poor fuel economy is NOT a thirsty engine. It is in fact, weight. The more weight you have, the more power and torque you need to propel it, and so you need a bigger, thirstier engine. Load your car to the brim with luggage, and get a feel for how much harder the engine has to work and how breathless it feels doing jobs it normally copes with easily.

Mazda’s first goal, lightweight, lead to them revisiting the basics. The design of the car frame. They set out to not only improve rigidity, but reduce weight while they were at it. By simply redesigning the basic framework of the car and using a larger amount of high-tensile steels, they claim a 30% improvement on rigidity, but also a near 10% reduction weight.

That may not sound impressive, but take our 1956kg Mercedes S350, that would mean a weight saving of over 150kg! And that’s before you attach a single body panel, piece of trim or any mechanicals.

The same process was applied to the suspension, by changing the design of the individual components to be a naturally stronger component, less material is required, reducing costs and weight. In fact, Mazda have said this has contributed to a 14% weight reduction, putting out savings so far on just a rolling frame of over 20%.

Our S350 would now weigh a massive 430kg less! And we are still yet to add an engine, a gearbox, any interior trim, or even a single body panel.

The Gearbox:

With the MX-5 and rotary-powered RX sports cars as flagship models, Mazda should know what a good gear change feels like, so they applied the same principle to the ordinary cars. This pursuit lead to more than just a claimed slicker, smoother gear change.

In the manual gearbox, the six speed unit is a whole 16% lighter, around 3kg and improves fuel economy by 1%. Small amounts, but these many small amounts add up.

The Engine:

Petrol:

The SkyActiv-G Petrol Engine

Known as the the SkyAtiv-G engine, Mazda engineers were sent away to try and reinvent the wheel.

Like the DieSotto engine, Mazda engineers ramped up the compression ratio, in this case to 14:1, a rise from a standard 11:1. Like the advantages of the DieSotto engine, it makes for a much more efficient combustion process and allows for more power and torque for the same amount of fuel.

However, this created other problems with removing exhaust gas fast enough to prevent ‘knocking’, a term for uneven burning due to hot exhaust gases remaining in the cylinder. So Mazda changed the exhaust manifold system from a 4-1 unit to a 4-2-1 system, preventing back-pressure and so ensuring an efficient burn process on each cylinder.

On top of the efficiencies of direct injection and high temperature spark plugs, this engine is 15% better on mpg and also develops 15% more torque as well as massive savings in emissions without the need for engine down sizing or the addition of a turbo charger.

In fact, the naturally aspirated, 2.0l petrol engine will develop a claimed 163 bhp and around 155 lb/ft of torque, and when fitted to a 2012 Mazda6 saloon should achieve around 48 mpg, a figure that puts this petrol engine right in the mix with Diesel motors. The emissions, claimed to be around 135 g/km of CO₂ would mean a years car tax would cost just £115.

Compare that to a brand new Mondeo. A 2.0l petrol will net you an engine with 142 bhp and 136 lb/ft of toque, capable of just 35 mpg and emitting a whopping 189 g/km of CO₂, which will demand £245 for a years tax.

In reality, the Skayactiv-G engine makes fine reading compared to a 2.2 diesel Modeo, which has 172 bhp and 295 lb/ft to its name, capable of 45 mpg and emitting 165 g/km of CO₂, which is going to cost you £50 more than the Mazda at £165/year.

Diesel:

The SkyActive-D Diesel Engine

With the petrol making a 2.2l Diesel engine look a little foolish, then the SkActiv-D 2.2 Diesel engine should make its rivals look laughable.

For this engine, Mazda actually lowered the compression ratio to 14:1 from 16:1, but made the ignition process longer and slower to allow a more even combustion process and means less black diesel smoke.

It also means the engine doesn’t need to be so beefy, so Mazda shaved 28kg from the engine weight by making the block from aluminium rather than iron and reducing the weight of the cylinder head.

That wasn’t the end of the challenge as Mazda have been forced to utilise more advanced injectors to combat ignition problems during cold-start up.

Finally, they added two-stage turbo charging to allow for optimal driving conditions. It means, Mazda can brag about their Diesel engine not requiring NOX treatments to prevent high nitrous oxide emissions that is the Achilles heel of the diesel engine and is currently solved by a power-reducing NOX collector.

So when Mazda announced the CX-5 crossover in July 2011, equipped with the 2.2l SkyActiv-D engine, the details they revealed told of 173 bhp, 305 lb/ft of torque and emissions of less than 120 g/km of CO₂, meaning this massive, Audi Q5 sized SUV will cost a remarkable £30 per year to tax. In comparison, a 2.0l TDI Q5 has 167 bhp, 258 lb/ft attempting to shift 1755kg worth of car, which results in just 45mpg and, with 165 g/km of CO₂, will set you back £165/year for tax.

In the Mazda6 test mule, this same engine is capable of 65mpg and just 110 g/km of CO₂, putting the cost of a years road tax at just £20. In fact, both these engines are so good that there are already compliant with the Euro VI emissions regulations due in 2015, Mazda completely ignored the current Euro V.

So forget your heavy, expensive, headline grabbing hybrids and range extenders, ignore the electric cars that are more prototypes than feasible cars and leave the Hydrogen fueled cars of tomorrow for tomorrow.

Mazda, a pokey little Japanese company, who have played second fiddle to Ford for twenty years and relentlessly pursue a dead technology and have a insatiable love of the cheap sports car, have developed some ordinary engines that will go in ordinary cars, that will cost pretty much what they cost today.

And yet in the real world of traffic and variable speeds and lead-feet, and in the statistical world of Combined MPG, expensive Tax discs and emissions regulation, can really mix it with the headline grabbing, sun-shining-out-the-backside, eco-cars.

I'm not trying to say the alternative fuel cars will never be mainstay, I'm looking forward to the days of the high power, instant torque electric motor, but Mazda are able to show how much development there is left in the internal combustion engine. If Mercedes had the motivations of Mazda, that astounding DieSotto engine would be everywhere. Before they announced the SkyActiv program, Mazda issued a press-release describing the initial negotiations with Toyota to lease the Hybrid system powering the Prius.

Unlike Mercedes, Mazda decided to go for the advanced technology rather than the band wagon, and I respect Mazda all the more for it and as far as I’m concerned, they deserve the rewards of acknowledgement and sales figures for their bravery.

MD