This week, following the VW emissions debacle, I’m going to give you a master class in understanding the new Euro 6 legislation and the effect on both petrol and diesel engines along with some relevant information that I hope you will find of use.
It’s not as boring as you might think because there has been a major change to the driver maintenance of diesel cars that you might like to consider before choosing diesel for your next car. I won’t go through the whole of the European Emission standards since they were introduced in July 1992 but I’ll touch on a couple of relevant points before bringing you bang up to date and reveal a couple of things you may not know about.
When Euro 1 was introduced it was really set up to provide drivers with information about the emissions from their new cars. Whilst limits were set for just a few of the exhaust emissions, CO2, Hydrocarbons (HC) + Nitrogen Oxides (NOx) and Particulate Matter (soot) they were more advisory rather than enforceable.
At the time there was a lot of discussion going on around CO2 and the effect on the environment but more important on the atmosphere, remember the discussions about the holes in the ozone layer? So as each new standard was introduced by the EU they changed from being advisory to statutory and more emissions became regulated. Testing standards were introduced and standard test conditions were introduced to laboratory standards.
Cars tested are not, as some believe and reported on recently, selected by the manufacturer and passed over for testing. Test cars are normal cars randomly selected from the production line and tested whilst being witnessed by Government agencies. In every case there has to be consistency. The environment is very carefully controlled.
The temperature, fluid levels and even tyre pressures are all set. This is about to change in 2017, something I don’t agree with, when they carry out measurements on the road instead of in the lab using portable measuring equipment. This will be known as Real World Driving Emissions (RDE). Really? what the hell is ‘real world’?
Its the same argument over fuel consumption figures. I can drive my car down the same stretch of road 3 days running and return three different MPG’s. Stick my son behind the wheel and you’ll return different readings again. In my opinion there is no such thing and once a car is out on the open road all sorts of dodgy things can be done to ‘fool’ the test equipment.
Anyway, back to Euro 6 which came into force in September 2015. This set the standard for petrol and diesel engine measurements and set emission limits. The limits are set for CO2, along with NOx (the gas that VW was misrepresenting), Carbon Monoxide (CO), Hydrocarbons (THC and NMHC) and finally Particulate Matter that is particular to Diesel (get it – sorry about that).
Whilst CO2 has always been the main concern of environmentalists and Governments around the world NOx has come to the fore with links to lung conditions and even premature death. These links are always debatable but assuming that the data is accurate the problem was already being dealt with by the EU with the introduction of Euro 6. The Euro 1 level of NOx was 780mg/km for diesel engines and 480mg/km for petrol.
Euro 5 saw diesel levels drop to 180mg/km, a huge drop and Euro 6 dropped the level in diesels to 80mg/km compared to 60mg/km for petrol – virtually the same. But in order to achieve this result in diesel cars an additive needs to be added to the diesel, something I’ll come onto in a moment.
There are two questions arising. Are diesels being unfairly demonised and as a driver should you be selecting petrol or diesel for your next car? Fuel consumption is still a big deciding factor for those covering high mileage but should it be such a deciding factor when most drivers are covering around 10,000 miles per annum?
Town mileage can in fact be more economical driving a petrol car compared to a diesel and with Ford working towards a petrol engine that will return 100mpg we may not be far away from the time when petrol cars are more frugal than diesel. But by then the environmentalists will complain that petrol engines always have and always will kick out more CO2’s than diesel. So what should you consider and what has Euro 6 changed?
First of all diesel’s spew out particulates, soot to you and I. However, these are captured by a particulate filter fitted into the exhaust system. However, the particulates are captured in the filter which then needs to be maintained to prevent blockage which will result in lost performance and ultimately the replacement of the filter which can cost up to £2,000.
In order to ‘clean’ out the filter you need to drive the car at more than 50mph for more than 15 minutes every month (see the manufacturer’s handbook). This creates a chemical action that effectively burns off the soot but for some who only drive locally this can be a bit of a chore. There is also the driving style when driving a diesel car. Even the latest cars suffer from a little turbo lag,
This means when pulling away from lights or out of a junction, you put your foot down on the accelerator and it takes a second to get the power into the wheels. You get used to it but it feels a bit weird if you have never driven a diesel before. Oh and a personal tip, always put a plastic glove on when filling up a diesel, in fact I always put two on as the smell seems to immediately absorb into your hand and stay with you for a week, even worse if you transfer onto the steering wheel. Petrol isn’t anywhere near as bad.
Another factor is cost. Generally diesel cars are more expensive than petrol to buy but when it comes to leasing diesels are in such high demand that the resale value ends up making diesel’s cheaper to lease than petrol so a bit of an advantage there. So what has Euro 6 done to make diesel’s less attractive? Well, in order to achieve the lower NOx emissions cars now require an additive called AdBlue.
In most cases the AdBlue reservoir is sufficient to last between services but as some drivers have found, depending on driving style and types of journey the reservoir needs to be topped up between services. Whilst you can buy AdBlue from anywhere that sells oil such as Halfords and is relatively cheap if misused or not topped up when the indicator light comes on you could be into some costly repairs or at best the engine not starting. So bear in mind if you are about to buy or lease a new diesel AdBlue is now something else to take into account.
Finally there seems to be a tide of hate spreading across the country against diesels. Boris has started the ball rolling by saying that any pre-Euro 6 cars will have to pay an extra tenner to enter what is known as the Ultra Low Emission Zone in London. Some councils have already started to charge extra for parking permits if you drive a diesel. Islington Council in London is set to introduce a surcharge of £96 for anyone with a diesel car from April and they don’t seem to be differentiating between Euro 6 and pre-Euro 6. Totally unfair!
So there you have it, you can now make an educated decision between petrol and diesel. The only other thing I haven’t mentioned is Benefit In Kind tax if you run a car through a limited company. The chancellor had planned to eliminate the 3% loading on diesel cars but following the emissions issues with VW he took the ill informed decision to retain it. By Graham Hill
