The Death of Diesel Engines Finally A step Closer !

Foxhole Norman wrote: »

Plenty of studies have shown that diesel fumes are worse than petrol, petrol may produce more but are less harmful. Diesels should be kept for commercial vehicles, Buses/Trucks and people that do ridiculous mileage. The amount of diesels in Europe confined to cities is ridiculous due to all the tax breaks they got in the past few years.

The funny thing is that people go on about dirty diesels and that they should be banned. Yet if you put a petrol engine on a bench with a diesel it will produce over 3 times more NOx as well as all other emissions I mention above are higher. However the cat saves the petrol on emissions and NOx a diesel with a cat would have lower emisions than a petrol with a cat including NOx so to say a petrol engine is cleaner than a diesel is incorrect as the petrol is producing more emissions than the diesel it's just the cat that's saving it.

The important thing to know about this is that when a cat is cold it doesn't work at all so when you cold start a petrol engine it's putting out 3-4 times more NOx than a cold diesel. Also if the cat becomes defective which they often do you are producing a serious amount more emissions including NOx than a diesel. Anyway I'm not going to argue it out anymore.

I think urban air quality is never going to see petrol or diesel come out as a winner - electric is what has to be developed in densely populated areas. Light rail, trams, electric cars, scooters etc.
Delivery trucks, construction equipment and light agricultural stuff for parks or whatever etc will continue to be a necessary evil.

CiniO wrote: »

I though it was 51% and only for those who are on salaries over 33800 p/a

Yes I think you're right. Used to be a little more I think until USC was reduced a little at some stage?

CiniO wrote: »

and only for those who are on salaries over 33800 p/a

Yes, I was struggling a little to pull something positive out for the greens. I wouldn't say telling people on less than 33k they can spend 1K minus twenty something per cent on a bike is much help really. But hey, chape tax on the new cars and even cheaper bikes for those with more money eh?

Haha, I was delighted with it. And taken completely by surprise that the government would encourage something that they didn't have a load of levies on!

captainspeed wrote: »

The evidence against diesel engines (in terms of their harmfulness to humans) is overwhelming. Also, a diesel produces 13% more CO2 per litre burned than a petrol engine. So a diesel engine that does 20% more mpg than a petrol is only about 6-7% better for CO2.

Petrols aren't as clean as a whistle, but they're a LOT better than diesels for us.

Leaving all of that aside, diesels have their place, for people who drive on motorway and/or drive over 18,000 miles a year. That's what they were designed for and that's what they were intended for, to make life more affordable for those who by necessity or by choice do a lot of driving every year.

They most certainly were NOT intended for Bridie to go down the road for a few messages or to go into town to pick up the kids after school, or for low mileage motorists - but that's what they're being used for at the moment because of Ireland's ridiculous taxation system that is totally skewed towards diesels - both on the new market and secondhand.

Even when manufacturers release low CO2 petrols, people still spend thousands extra on a diesel to save that extra €10 or €20 on car tax (admittedly they'll most likely get the extra cost back come resale time anyway). That's something that needs to change, and the sooner the better for everyone.

Unfortunately not for long

Much of the cause of particulate matter in diesel engines is because it burns very lean, at extremely high temperatures under enourmous pressure - not an inherent problem with the diesel fuel itself. A by product of a lean burn at high pressure is you don't burn entirely evenly, your air-fuel mix is under immense compression and these all combine to create extremely small particulates in the less-burnt parts of the mix which get pushed out the exhaust. These are the most harmful in terms of air quality and health.

Now, to petrol, in a bid to drive CO2 emissions down, they're putting very low displacement petrol engines into cars (e.g. Ford 1.0L EcoBoost).
To compensate for the loss of power from the reduction in displacement they're moving to turbocharging and direct injection - essentially a much leaner burn at much higher pressure than a traditional petrol engine (same as diesel technology!) And the by-products are exactly the same - a lean burn at high pressure and particulates pushed out the exhaust from any part-burnt combustion.

Which is ironic really, because now Bridie's new generation petrol engined school runner car is going to be riddled with the same carbon-choked-EGR and blocked particulate filter technology as the "unsuitable diesel" equivalent, giving worse fuel performance and higher maintenance costs than it's previous petrol iteration and just as bad NOx and PM output as its equivalent diesel, all in the name of being green...

Make no mistake, environmental concerns are not at the heart of this change of heart - it's a massive loss of tax revenue from pure CO2-based taxation bands. Start taxing on NOx, PM in addition and costs are going to rise all around, not just for diesel drivers.

Deleted User wrote: »

I would say that Governments are waking up to the fact that the cost to treat pollution related illness will be far greater than the loss from lower C02 vehicles.

Haha - someone elses problem - in Ireland they are only worried about the next election.

So, ultimate efficiency based on CO2 gives nasty air quality side effects whether it's diesel or petrol. An inconvenient truth...