Volkswagen Passat B7 - Revs for DPF Regen? - fredthefifth

My Passat has had the emissions fix which I read can result in more soot and earlier DPF failure. Guidance is that I should have regular runs with revs over 2000rpm.

Trouble is on motorway runs in 6th at 70mph my rpm is just below 2000rpm. So do I have to change down? How far for? etc

Just wondering.

Ta.

PS: Car is running fine post fix but my usage has changed so doing more short trips.

Volkswagen Passat B7 - Revs for DPF Regen? - skidpan

There are hundreds of urban myth about DPF's but one simple fact is it will not carry out a regen until the ECU intructs it to. Unless a regen is due all regular runs will achieve is to waste fuel and your time.

The best urban myth is to drive at 70 mph in 3rd for 1/2 an hour to blow the soot out. All that does is wastes fuel and deafens you. The soot is bonded to the dpf and need s regen to shift it, if it simply blew it out there would be no point having a dpf.

If your usage suits a dpf equipped car you have nothing to worry about, just carry on driving normally.

If your usage does not suit a dpf equipped car sell it and buy a more suitable petrol.

FYI our Kia ceed had a recomendation to keep the revs between 1600 and 2000 during a regen. 70 mph was about 2200 rpm so when we first got the car and spotted a regen was taking place we simply continued at 70 mph if we were on a dual carriageway/motorway. But we spotted that reducing speed/revs made a regen last a shorter time and the fuel computer recorded a a much better mpg during the regen, basically Kia know a bit about their cars.

What do VW recommend.

Volkswagen Passat B7 - Revs for DPF Regen? - RT

There's two types of regeneration, active and passive - the comments above relate to an active regeneration.

A passive regeneration occurs when the exhaust is hot enough in normal driving to burn off some of the soot - some driving patterns are hard enough that no active reneration is ever required, passive ones being adequate to avoid a build-up of soot in the DPF

Volkswagen Passat B7 - Revs for DPF Regen? - fredthefifth

I have no idea when the car is carrying out a regen.

I can't afford to change it at the moment, so trying to reduce the risk, not unreasonable surely.

Volkswagen Passat B7 - Revs for DPF Regen? - Railroad.

I have no idea when the car is carrying out a regen.

You won't. The ECM doesn't tell you. Passive regenerations take place all the time when the exhaust is sufficiently hot. The cooling fans will run during an Active regeneration, so that is an indicator of when it's in progress. If all else fails anyone with VCDS can carry out a forced regeneration. Check the VAG forums for someone who has VCDS near you.

Volkswagen Passat B7 - Revs for DPF Regen? - fredthefifth

I have no idea when the car is carrying out a regen.

You won't. The ECM doesn't tell you. Passive regenerations take place all the time when the exhaust is sufficiently hot. The cooling fans will run during an Active regeneration, so that is an indicator of when it's in progress. If all else fails anyone with VCDS can carry out a forced regeneration. Check the VAG forums for someone who has VCDS near you.

Point taken, but fyi my reply was based on skidpans reply which implies that a regen can be "spotted".

Volkswagen Passat B7 - Revs for DPF Regen? - craig-pd130

At around 2,000rpm you're close to the peak torque which is ideal, the exhaust gas temps will be plenty high enough. No need to use a lower gear.

As Skidpan points out, higher rpm = more fuel burnt = more soot.

 

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