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"Don't buy a car fitted with a DPF – diesel particulate filter

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Dont buy any car fitted with a DPF ( diesel particulate filter )

I recently read this on a car forum and it got me thinking……

What is a DPF?diesel particulate filter

Are there any new diesel cars without a DPF?

Why are car manufacturers fitting diesel particulate filters?

If your car has one fitted will it block up or can you prevent that from happening?

Is it possible to remove the DPF and for the car to continue running properly?

What is a DPF?
If your car has one fitted will it block up or can you prevent that from happening?

A DFP is a trap which catches the sooty particulates in diesel exhaust fumes. It’s a filter like a vacuum cleaner’s filter – you have to change or clean it regularly for it to work efficiently.

The modern ones are cleverly designed so that they are self- cleaning ; the soot is burnt off at a very high temperature; above 40 miles per hour (64 km/h)

electronic control unitThe ECU (the car’s ‘brain’) detects when the filter is 45% full and subtly alters the engine timing to make the exhaust hotter and thus burn off the soot.

If not (and high enough temperatures have not been reached ) and the warning light stays on you will need to try and clear it by simply driving for 10 minutes or so faster than 40mph.

If soot levels continue to rise in the filter (mainly due to slow driving) a costly  replacement filter may be necessary

This high temperature is mainly achieved when motorway driving.
What happens to the accumulated soot if you drive mostly in town?
The car has to driven at speed to create an engine temperature high enough to burn off the accumulated particulate.

Are there any new diesel cars without a DPF?
Why are car manufacturers fitting diesel particulate filters?

A difficult question to answer.  According to Wikipedia most 1st world countries have introduced tighter and tighter emissions  controls but no-one has made DFP’s mandatory. But all vehicles will be fitted with them eventually!

Is it possible to remove the DPF and for the car to continue running properly?
Yes it is possible to remove the DPF but you will probably need to have the ECU reprogrammed to compensate.

 

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