NOx, Hydrocarbons and Worse – What’s Else is Coming from your Exhaust Pipe?

As automotive consumers, we think we’re pretty well informed. We read all the blogs and all the magazines, pouring over the all important numbers: 0 to 60 times, miles per gallon and – increasingly – CO2 emissions. That last one is interesting, as it’s only come to the mainstream public’s attention in the last seven years or so. Anyone would think that the only noxious chemical cars put into the atmosphere are CO2, but you’d be wrong.

Nitrogen oxides (NOx), hydrocarbons, diesel particulates and carbon monoxide are also put out by our daily drivers. Think of the worst parts of cigarette smoke and the fumes from burning plastic and you’ll have a good idea what I mean. Premature births, lung cancer and smog – all attributable to these noxious chemicals.

You may be surprised at the vehicles that are very good on CO2 and very bad on NOx and hydrocarbons. By adding the two together, we get a milligram per kilometre rating. So here are the best and worst from the UK’S Vehicle Certification Agency:

UK's best performers

Skoda Yeti 1.2 105PS 49mg/km

Nissan Qashqai+2 2.0 71mg/km

Honda Insight 1.3 IMA S/SE 73mg/km

Porsche Cayman S 3.4 79mg/km

Honda Insight 1.3IMA ES-T 5dr 82mg/km

UK's worst offenders (mg/km)

Nissan Pathfinder 2.5 dCi 190 1,150mg/km

Seat Ibiza SC 1.2 12v 70PS 1,026mg/km

Citroën C5 1.6i THP 1,010mg/km

Audi A4 3.2 FSi Multitronic 999mg/km

Mercedes B-Class B160 BlueEfficiency 994mg/km

Would you believe that a 2.5L Volvo V70 estate is in some ways better for the environment than a 1.3L Fiat 500 with start-stop engine tech? Try 201mg/km versus 484mg/km. And would you of guessed a Porsche Cayman S would be, in one way at least, better for the environment than a Mercedes-Benz B160 BlueEfficiency?

It just goes to show that the more you know the better off you are. One can only hope that, in time, these details will appear on the same stickers that tell us mpg and CO2 emissions so car buyers can make a fully informed choice.

By Tristan Hankins

Source: VCA via Telegraph