EXHAUST POLLUTION AND ALL THAT JAZZ

A major problem that we are all facing, and it promises to get worse, is the shortage of fossil fuels that is leading to what is called ‘peak oil.’  Peak oil basically is where the maximum production of oil from known sources is less than the demand/consumption.

Various governments are facing up, at last, to the fact that energy, as we currently know and use it, is getting scarcer, so the ‘Greens’ who have been screaming for years that nuclear energy must never be used, and coal is ‘too polluting,’ are all being hushed up because nuclear is actually better than people dying of cold and industry falling apart because it has no power to manufacture products, and so on. And the new systems of using good quality coal, a product of which we still have many millions of tones underground in Europe, promise that with new power stations designed to ‘capture the carbon output,’ we can actually get to the stage where OPEC will be begging us to buy their black liquid gold because they will not have enough storage facilities for it. But what about vehicle exhaust pollution?

Some World governments are taking a tough line to get us all to reduce the pollution that spews forth from our vehicle exhausts and older cars in daily use, so they are due for a tough time.  Excepted are the classics, but already now in some cities in Germany, real ‘classics,’ cars and motorcycles that are older than 25 years are forbidden from entering the city centres without a licence for an approved rally, etc.  Now, we all ask, how do engines, specifically cars at the moment, cause pollution?

As I have personally found, a small engine in a big body can cause more pollution that a big engine, because it has to work much harder to propel the car along. The tests for the EU homolgamated pollution figures are carried out according to EU Directive 80/1268/CEE plus following amendments, under laboratory conditions, so all vehicles as used on the roads, not just the engines, have the same benchmark to work at.  With that in mind, our new Ford Focus, although it has the 1.8 litre diesel engine tuned for 115 BHP, is the most economic of the new Focus range with an out-of-town fuel consumption of over 65 MPG.

But it has a CO2 figure of 137 Gm/km.  Some of the 1.6 litre versions have a CO2 figure of under 120 and qualify for zero special purchase tax, but CAN in real conditions use more fuel on the road, which proves what I have just said, as the driver may use the accelerator more to stay with other traffic or just to get a move on.  But according to the tests, they use less fuel but I keep accurate fuel consumption figures so I will report on my experiences in a few weeks time. How is it that the same basic engines can be produced with different power settings, especially diesels?

All modern engines, even some small scooters, have fuel injection systems.  I may go into how these work in a later article if interest is shown, but no room here. With electronics, it is much easier to meter the supply of fuel, (compared with the older carburettors) to match the air going into the engine and most cars now have the accelerator results controlled by the system, not the driver.  By that, I am saying that although the driver may put his foot hard down on the accelerator pedal, the electronic control system controls how much the working side in the engine actually moves.  In a diesel, the speed is basically controlled by the fuel supply and in a petrol engine, by the air supply.

Now I know that someone out there will say that is not strictly correct now but basically it is and always has been, and these articles are intended for lay people, not ‘techies,’ so I am deliberately keeping it simple so the reader does not turn the page. What does that mean to us owners?  It is possible to buy a car with a homolgamated CO2 figure of less than 120 Gm/Km and by fitting a new electronic chip, change the fuel settings so the engine produces considerably more power, but with an increased CO2 figure and higher fuel consumption, plus if you overdo it, reduced engine/transmission reliability.

The ITV/MOT
For some time now, part of the test has been the measuring of the CO2 figure by placing a sensor in the vehicle’s exhaust pipe and revving the engine to about 3,000 rpm or more, depending on whether it is petrol or diesel.  Anyone who has modified the fuel system will be ‘found out’ because of the higher CO2 figure and the vehicle many fail the test.  But of course, it is possible to have the original manufacturer’s chip replaced for the ITV test, but is it all worth the trouble?  It is a personal decision, and there are specialists who will do it for you with a power-test on a rolling road machine to show you what has been achieved.  They can also make the car less fuel thirsty or just check that all is well in your fuel control system, and there is much more to systems with Lambda sensors, etc to think about.   Quite involved, and the editor only allows me so much space.

This week’s check point
Is your spare tyre pumped up correctly?  You would be surprised how many times I have stopped in the last 50 years to help ladies with car punctures where the spare has been flat because they never check it.  TRUST NOBODY.