It’s no news flash that petrol doesn’t appear to be getting any cheaper. People everywhere are asking what they can do to save fuel, and often the answer is to change your car to one that’s more fuel efficient. That’s simple, right? But what type of car should you choose? Just maybe, you should try a hybrid car.

Hybrid’s are the talk of the town these days. Current hybrids like the Toyota Prius & the Honda Civic Hybrid are both stylish and available in great colours, they will make your daily commute less expensive and more enjoyable. Once you examine the characteristics of a hybrid, how could you not choose to run to the car dealer right now and buy one? Well, we all wish we could just simply do that, but before you run out and take the plunge, maybe you should learn a bit more about these cars.

A hybrid car is a vehicle that uses an electric motor combined with a conventional internal combustion engine. A combination of a conventional propulsion system and a rechargeable battery bank installed onboard the vehicle work together to give the vehicle better fuel economy than conventional petrol or diesel cars, that’s the generalised theory anyway.

Top Hybrid Cars of 2008 is a video I found that might interest you, take a look.

Hybrid cars work differently to battery electric vehicles because the battery bank used in a hybrid car does not require charging from an external source. Instead, in order to get a charge, kinetic energy is generated by way of regenerative braking. Furthermore, some hybrid cars make use of their own combustion engine to create electricity. The combustion engine does this by spinning an electrical generator or alternator . The spinning does one of two things. It can either recharge the battery or in a more direct way, it can cut out the middleman and give power directly to the electric motor. This motor is what then drives the vehicle.

Therefore, because this fuel-sipping vehicle can generate its own electricity, it is very different from a vehicle that is run strictly on batteries. But, there is no waiting while your car charges up outside in the garage before you go to work. All you have to do is get into the car and drive.

It is true that some people have experimented with electrical vehicles in the past. However, the introduction of the hybrid cars outdid these types of cars when they came on the scene.

Because the hybrid car is so innovative in the way it powers itself and the way it is able to save you money on fuel, it’s currently believed to be the car of the future. At least that’s what many car makers believe, and many consumers agree with them. In the next generation of new cars, a factory fitted ‘bolt-on’ hybrid should become available from many makers, there are many rumours in the industry to suggest that this new wave of bolt-on hybrid options will become a reality. Hybrid cars are expected by some to become the industry standard in the very near future.

So if you want a car that’s enviromentally friendly, saves you money on fuel, and benefits from a lower road tax band, perhaps you should invest in a hybrid. As the car industry is still too far away from a viable hydrogen/water fuel alternative, buying a hybrid electric vehicle is probably the most sensible alternative for those looking to buy a new car today.

Throughout North America, diesel engines are generally used in larger trucks, where the low stress, high efficiency cycle will lead to a much longer engine life and lower costs to operate.  These advantages also help to make the diesel engine ideal for use in the heavy haul industry.

Cars however, continue to use petrol, primarily due to the consumer desire for a wider range of RPM. In Europe, the use of diesel engines with cars is far more common.

Even though diesel engines are more efficient when throttled down, they aren’t suitable for most types of aircraft. The higher compression ratios of the diesel cycle demand a much stronger block, head, and almost all moving parts in general. These stronger parts add a lot of weight, or a lot of expense, especially if lighter alloys are being used.

The Otto cycle engines are much cheaper to build for these reasons, although they have long been overtaken by the turbine engines. For the same displacement of the engine, Otto cycles will produce more actual power than a Diesel cycle can, because the fuel will burn at a much faster rate, allowing more power strokes per minute than a standard diesel can offer.

What this means, is that less fuel has to be carried.  Additionally, commercial aircraft is normally run at preset limits, so that Otto cycle engines used in aircraft don’t suffer anywhere near the efficiency penalties that land vehicles do. Heavy equipment, such as those used in mining and construction, almost always uses diesel engines.

Diesel engines are also used with submarines. In these types of submarines, the diesel engine is run when the submarine is on the surface, which charges the batteries that power the submarine once it is submerged.

All across the world, diesel engines serve many different purposes. They are used with almost all types of heavy machinery, and other vehicles. Petrol isn’t the way to go with heavy machinery, as the engines simply can’t withstand the beating.

Diesel has been popular for many years with machinery and submarines, simply because the engines can last for years and years. Although they won’t offer as much speed as Petrol, the torque and power is still there.

Let’s assume, that you own a farm. You produce grain and have a lot of straw. You’d like to make your energy on site from the biomass you have available. You might plant your fields with rapeseed or canola and produce biodiesel. But you’d need to get methanol and lye first, since both of them can’t be made there! And you can use your biodiesel only in compression ignition (diesel) engines. And what if you have an old genset powered by spark-ignition (gasoline / petrol) engine? I think I might have a solution for you…

You’ll make use of a technology that’s more than 200 years old. It’s greatest development took place during World War II in 1940s in Europe. At that time most of petroleum-derived fuels were used by military and there was no fuel left for civilians. So they made their own fuel, the wood gas from wood or charcoal. In some countries 95% of civilian transport (trucks, buses, even fishermen’s boats) were fueled with this gas.

What is this wood gas? From chemical point of view it’s a mixture of combustible carbon monoxide (CO), hydrogen (H2) and methane (CH4), dilluted with some water vapor, carbon dioxide (CO2) and nitrogen (N2). This gas can be easily used for almost every internal combustion engine. Well… except for the most modern ones, they’d require to have their electronics to be modified.

How wood gas is made? When you heat wood it is pyrolysed, i.e. all the tars vaporize. When you add some oxygen, the carbon bound within the wood cells is burnt to carbon dioxide. The vapors burn too. When those burnt gasses pass through a layer of very hot char, they are reduced to carbon monoxide and hydrogen. A small amount of methane is also produced. When the gas is cooled and cleaned of any tars and particles, it can be used in internal combustion engine, boiler or any other device!

What do you need to produce your own wood gas? You’d need a device that’s called gasifier. It consists of fuel hopper, gasifying chamber and a set of filters. It’s very easy to build, the people during WWII made it out of old water heaters and stuff like that.

Is wood gas safe? Well, if you don’t inhale it, you’ll be OK. Carbon monoxide is very toxic and poisonous, so caution is required when using wood gas. From the engine point of view, if it’s clean, it’s safe. The tars might condense inside the engine, for example on valves, which might cause the engine to fail. The particles would probably destroy the contact surfaces on pistons and cylinders. If the gas is too hot the engine will not work (hot gas is diluted and has small energy content per unit volume), but it will not harm it.

Any drawbacks? One that’s worth mentioning. Petrol engines will suffer 1/3 power loss — the wood gas does have small heating value. Diesel engines will not suffer such power loss, since they work on stratified mixtures and because of that you can introduce more wood gas to recover the power loss. You’d need to leave some small amount of diesel to be injected to the cylinders to ignite the wood gas.

Interested? One liter of petrol / gasoline can be replaced with 2.5 – 4 kg (5.5 – 9 lbs) of wood. How cool is that!

About The Author
Krzysztof Lis is MSc of mechanical engineering, graduated on october 2007, and lives in Poland. For 5 years he owns a site on biofuels (especially biodiesel and wood gas) and other alternative energy sources. He started translating this site to english http://alternative-car-fuels.com.