Forums Forums Enthusiast Forums A - Z Autowirral vw cheats on diesel tests

Diesels first used before 1979 have a visual smoke check, after 1979 they are measured and visual.

If a diesel first used after 1979 doesn't pass the fast check, then it has do do the detailed check which has different limits depending if it is turbo or non-turbo and whether it was first used before or after 2008.

So basically there are three year dependent measurements, pre 1979, 1979-2008 and 2008 onwards, the 2008 onwards being the strictest.

I like "Zero smoke", but "virtually' is just a joke. I followed a fairly new black Merc up Leasowe Road last week. Each time it accelerated huge clouds of black smoke were emitted, and I mean huge, it was almost impossible to see through them. He eventually turned right in to Box Lane, again with huge clouds of smoke. I just hope he was going to a garage for repairs! Otherwise he should be off the road.
By the way is it true that some diesels are programmed to pump raw fuel into their exhausts in order to burn their Cats clean. If true I bet they don't do it on emissions tests!

Some cars have an active DPF regeneration cycle which puts extra fuel into the engine so that it is burnt in the exhaust and increases the DPF temperature to burn off accumulated muck, this is an accepted method and testing wouldn't be performed while the car is doing a regeneration cycle.

Diesel should have regular higher rev driving (3000rpm or above) for at least 10 mins every week or two to keep the DPF and exhaust system relatively clean, this will generally reduce the need for the car to go into a regeneration cycle.

What happens if my VW has emissions cheating software : Click Me

Hypothetical question. What will owners say when their cars have had their software altered to lower the NOX levels and then find out how much the engine power has been reduced?

It shouldn't significantly change the engine power on the road.