Fuel econnemy and DPF regeneration 2.0TDI 190HP

[TheDaneWithSuperb]

I find that my Skoda Superb 3 Estate L&K 2.0TDI 190HP 6 Speed DSG from 2017 doesnt get that good fuel econnemy. Usually around 16km/l (44,8mpg UK or 37,3mpg US) on avarage. Seems a little low when its specs says 21,3km/l. I drive most of the time on country roads with speed around 85km/h and the avarage doesnt get much higher than 18km/l. Seems a little on the lower side to me. 

 

I also find that it seems to regenerate DPF a lot, which I believe could have an impact, is regeneration about every 150-200km normal? It seems way to often in my mind. 

 

Whats your experience? 

[Gizmo]

What’s you average journey length in miles?

 

I used to get low 50’s on a 40 mile commute. 
 

It sound like you are either doing lots of short journeys or the DPF regen is being interrupted? 
 

Mine would regen every few thousand miles. 

[cnc]

1 hour ago, Gizmo said:

What’s you average journey length in miles?

 

I used to get low 50’s on a 40 mile commute. 
 

It sound like you are either doing lots of short journeys or the DPF regen is being interrupted? 
 

Mine would regen every few thousand miles. 

I fully understand why you say every few thousand miles but I imagine you are thinking when you stop the engine and you can smell the burning and the fans keep running etc which is one type of regeneration.

 

The diesel with DPF is also designed to perform a 'Mileage regeneration' regeneration every 465 miles, although you may not be aware of this as the driver even if you stop the engine mid cycle.

 

Details on page 62 of this VW technical manual https://pics.tdiclub.com/data/517/820433_EA288.pdf 

 

Passive regeneration 

Passive regeneration occurs when the car is running at speed on long motorway journeys which allows the exhaust temperature to increase to a higher level and cleanly burn off the excess soot in the filter.

So it is advised that drivers regularly give their diesel vehicle a good 30 to 50 minute run at sustained speed on a motorway or A-road to help clear the filter.

However, not all drivers do this type of driving regularly – which is why manufacturers have designed an alternative form of regeneration.

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Active regeneration 

Active regeneration means extra fuel is injected automatically, as part of the vehicle's ECU, when a filter reaches a predetermined limit (normally about 45%) to raise the temperature of the exhaust and burn off the stored soot.

Problems can occur, however, if the journey is too short, as the regeneration process may not complete fully.

If this is the case the warning light will continue to show the filter is still partially blocked. 

In which case it should be possible to complete a regeneration cycle and clear the warning light by driving for 10 minutes or so at speeds greater than 40mph.

You will know whether active regeneration is taking place by the following symptoms:

• Engine note change
• Cooling fans running
• A slight increase in fuel consumption
• Increased idle speed
• Deactivation of automatic Stop/Start
• A hot, acrid smell from the exhaust

 

 

[Penpusher]

I posted this up recently on another query regarding fuel consumption and this is my result on a 3 week trip to Lithuania in May/June.  As the car was running continuously all day during the trip, I didn't notice any regenerations.

 

However, I'm retired and when I'm at home the car can spend several weeks on short journeys around town, especially during the winter.  The fuel consumption is worse at this time and drops to around the figures or even lower than those quoted in the original post and this is when I notice the regenerations and about a couple of times a year (usually in the winter) I have to drive up and down the Brecon Bypass a few times to complete them.  Yes, I know a diesel isn't the right car for me, but I bought it when I was still working and I'll switch to a petrol when I decide to change it.

[TheDaneWithSuperb]

The regens i get the most is the once you mentioned. Fans being on for a while after ignition cut with a smell of hot exhaust. I havent got a DPF Light at any time while I've had the car. Its has almost 71.000 miles behind it. 

 

My comute to and from work takes around 20minutes which all on country roads, with pretty sustained speed at 50mph. Might this be trigger that gets it to regenerate? Because it sees pretty constant speed?

 

In the weekends we usually drive 50-100miles trips regularly. 

[J.R.]

Has it had the "emissions fix"?

[D402]

I do a journey regularly that, like your commute, is long and fast enough to trigger a regen but is too short for it to complete. When a regen is in progress the idle speed is raised, stop/start is disabled and DSG selects a lower gear. Watch out for this happening and extend your journey until things go back to normal, it probably won't take long. Otherwise the car will keep trying to regen on every suitable journey until it can complete. When it really needs to regen you will see the raised idle speed all the time, this is a sign that you need to do a long, fast drive.

[TheDaneWithSuperb]

7 hours ago, J.R. said:

Has it had the "emissions fix"?

Is there an officiel fix like they have to do it when its in for service, dont remember what its called.