Volkswagen has announced it is taking action to reduce particulate emissions of TSI and TFSI direct injection petrol engines with a particulate filter.
That has meant the introduction of direct fuel injection for modern cars, which injects fuel at very high pressure directly in to the combustion chamber from a common rail fuel line, rather than low pressure injection in to the intake we’ve been used to.
The transition to high pressure direct fuel injection has not been easy for car makers (Mercedes, in particular, has had huge fuel injection problems), but the upside has been that engines with direct injection are more fuel efficient, more powerful and emit significantly less CO2. But there is a big downside.
TUV Nord revealed as far back as 2013 that petrol engines with direct injection emit 1,000 times (yes, one thousand times) the levels of harmful particulates than a petrol engine with conventional fuel injection, and ten time more than a diesel engine.
This ridiculous situation, where previously clean petrol engines have started to emit huge levels of properly harmful particulates, is entirely down to the obsession with CO2 by legislators, compelling car makers to meet ever more stringent CO2 emissions levels and skewing taxes to direct buyers in to low CO2 cars.
That said, EU emission standards will force car makers to fit particulate filters to petrol-engined cars with direct injection before long to meet legal requirements, so Volkswagen is jumping the gun (a bit) by announcing it will start fitting particulate filters from 2017, clearly demonstrating (they hope) how environmentally conscious they are.
It’s not a hugely expensive task for VW (it’s estimated a particulate filter for a petrol car will cost around £35), but it does give them the opportunity for a bit of spin on a positive emissions story.
The process will start in June 2017 (why so long?) with the 1.4 TSI in the Tiguan and the 2.0 TFSI in the Audi A5, and VW say implementation will then follow in further models and engine generations.
Which gives VW headlines, but is hardly an overwhelming commitment to clean up their very dirty petrol engines as soon as possible.