Qashquai - Mileage to Burn Off Particulates

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Wed 21 Nov 2012 14:32
Qashquai - Mileage to Burn Off Particulates - Boy Scout

Can I run a diesel qashquai on the following mileage without getting into particulates burn off trouble. Weekly runs of 20 miles out . 2 hour break, 20 miles back rest of week doing short runs up to 10 miles. Holiday run in France 1700 miles once a year.

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Wed 21 Nov 2012 14:58
Qashquai - Mileage to Burn Off Particulates - Falkirk Bairn

20 mile motorway run - its not the roadspeed but the engine speed that will make the regen kick in - give it 2,500+ revs and it will work

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Wed 21 Nov 2012 15:17
Qashquai - Mileage to Burn Off Particulates - skidpan

20 mile motorway run - its not the roadspeed but the engine speed that will make the regen kick in - give it 2,500+ revs and it will work

Urban myth i am afraid. A regen will not start until its required, no amount of revs will start one until the sensors say so.

All that is required is to drive normally, nothing special needed, all this "drive at 3000 rpm on the motorway" will only waste diesel, it will not start a regen or clean your DPF.

Had a BMW with DPF for almost 5 years now. Do 15 miles each way to work 3 days a week plus local running, trips to outlaws and during the summer seaside trips, about 7000 miles a year in total. It does a regen when it needs to do one. I just let it get on with it.

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Wed 21 Nov 2012 15:25
Qashquai - Mileage to Burn Off Particulates - RT

It does a regen when it needs to do one. I just let it get on with it.

How do you tell that a regen is taking place - I'm just curious !

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Wed 21 Nov 2012 15:41
Qashquai - Mileage to Burn Off Particulates - skidpan

It does a regen when it needs to do one. I just let it get on with it.

How do you tell that a regen is taking place - I'm just curious !

The engine note becomes harsh and it sounds totally different when changing gear. The exhaust tailpipe is too hot to touch, normally its stays remarkably cool. The car drives no differently but after 5 years I have become accustomed to the subtle giveaway signs.

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Wed 21 Nov 2012 15:23
Qashquai - Mileage to Burn Off Particulates - craig-pd130

Short answer: it should be fine.

Long answer: most DPF-equipped cars do both 'passive' and 'active' DPF regenerations.

Passive is when everything's up to working temperature and the engine speed and load is sufficient to generate the constant 300+ celsius in the DPF matrix that starts oxidation (burn-down) of the soot. This will typically only happen once you've been driving for about 8 to 10 miles at a reasonable speed (most manufacturers seem to state around 40mph or so). Your weekly 20 miles each way run should cover this.

Active is when the engine management computers determine that the DPF has reached a given loading of soot, which needs to be cleared. At this point various things happen to increase the temperature in the DPF matrix to around 450 - 500 celsius to start a rapid burn-down of soot. Active regenerations are usually triggered on a mileage- or hours of operation basis too, as a failsafe.

My previous Mondeo IV and current Volvo are frequently used for 2 - 3 weeks at a time for journeys of 5 - 10 miles in traffic. No DPF problems with either in nearly 5 years.

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Wed 21 Nov 2012 15:31
Qashquai - Mileage to Burn Off Particulates - daveyjp
The only answer is it depends. Some cars are fine, others are a nightmare as a colleague with an Insignia who does a round trip of about 20 miles a day in busy traffic is finding out.

It was burning so much fuel to force regen he was getting 20mpg. The DPF warning has now come on, once fixed he's getting rid of it.
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Wed 21 Nov 2012 16:47
Qashquai - Mileage to Burn Off Particulates - daveyK_UK

Nissan are getting better than most at addressing the DPF issues, largely due to their partners renault who seem to be ahead of the game.

However, this is still a significant difference betwen the nissan and renault failure rates of DPF despite using the same engine (1.5)

This is down to the temprature and MPH when the engine engages for the DPF re-gen.

Renaults start their cycle at a lower temperature and mph than other manufactures, its largely why theire more recent moels have been trouble free in this area.

Where Nissan are now only starting to follow suit.

Desipte renaults best attempts, if someone buys a diesel and only does a 5 mile round trip each day, it will clog no matter how low you set the re-gen limit.

But why lose a sale by being honest to a customer who must have a diesel!

Edited by daveyK_UK on 21/11/2012 at 16:48

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Wed 21 Nov 2012 19:29
Qashquai - Mileage to Burn Off Particulates - unthrottled

What sort of speeds do you average on your commute? I'd say this a greater effect on DPF behaviour than journey length. As others have said, forget the low gear nonsense, the best gear for DPFs is the best gear for economy-the highest gear in which the car feels comfortable.

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Thu 22 Nov 2012 10:28
Qashquai - Mileage to Burn Off Particulates - Boy Scout

On 20 mile out speed is 12 mile motorway 70 - 80 balance 40-50, 20 mile back A roads leisurely 40 mph. May I thank all you kind people for your answers .

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Thu 22 Nov 2012 20:49
Qashquai - Mileage to Burn Off Particulates - unthrottled

Perfect. Very little fuel will be wasted. It'll sort itself out.

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Thu 22 Nov 2012 12:37
Qashquai - Mileage to Burn Off Particulates - Sulphur Man

The OP doesnt say which Qashqai diesel he/she is running.

The new 1.6cCI Nissan Renault alliance engine is designed to be much easier on the DPF. If that's the engine he's referring to, I wouldnt expect any issues with those typical journeys.

I've been running a 1.6dCI Qashqai since May. Thoroughly satisfied with the car so far, especially this engine. Average mpg was disappointing at first - 47/48, but has improved considerably to 54-ish after 6000 miles.

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Thu 22 Nov 2012 00:48
Qashquai - Mileage to Burn Off Particulates - 1litregolfeater

If you can time it to, outside the primary school, during the school run, that could be interesting.

I wonder what chemicals get released in this six-monthly procedure.

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