What is it with this "regeneration" thing ?

[dcdick]

As the title says .........

550 miles mixed driving with an eye on economy & struggling to get over 50mpg

Last week the car went into "regen" mode after a run down the motorway when it was parked up

Today it has done this 3 times after journeys of about 7-8 miles

Anybody any ideas (I will be contacting the dealer in the morning) ?.

Am certainly not going to put up with this fuel wasting nonsense as driving conditions are ideal during this warm spell we are experiencing lately.

I was sold the 1.6 diesel over the 1.4 TSI purely on the basis of fuel economy as the price was the same to lease with no premium for the diesel & as the performance of the 1.6 is fine for my needs it seemed like a win-win deal

What are people getting from their 1.6 TDI "blue motion technology" cars?.

My long term reading (by the car) is standing at 48.5 mpg which is 25 mpg shy of the published figures or around 32% less than it should be.

I know about the published economy figures & I should get within 10% of these seeing as I drive carefully. Will the engine "loosen up" enough to affect the fuel consumption figures enough to bring it up to where it should be ................ I don't think so !

The car is great to drive & the tech stuff fitted does make things easy but this fuel consumption/regen business is starting to annoy me & I get the feeling the dealer is going to stonewall me tomorrow (may be wrong though !)

Previous car was a 61 plate QQ diesel that had none of this regen stuff going on.

[mcmaddy]

what diesel have you been using?

[dcdick]

what diesel have you been using?

Shell & Esso, 2 lots of Shell & 1 of Esso so far. Standard diesel.
Shell today, had already had 1 "regen" before putting fuel in today.
Of the 3 garages I use for fuel 2 are Shell & 1 is Esso, Shell is my preferred fuel though but don't have a compelling reason to use Shell over Esso.

No BP garage near me come to think of it.

[Doctle Odd]

You can get the DPF removed, I hate them and EGR's. Your mpg is low even for dirty diesel on that engine. I'd start with a VCDS scan. You can get a forced regen as well

[algarve]

As the title says .........

550 miles mixed driving with an eye on economy & struggling to get over 50mpg

Last week the car went into "regen" mode after a run down the motorway when it was parked up

Today it has done this 3 times after journeys of about 7-8 miles

Anybody any ideas (I will be contacting the dealer in the morning) ?.

Am certainly not going to put up with this fuel wasting nonsense as driving conditions are ideal during this warm spell we are experiencing lately.

I was sold the 1.6 diesel over the 1.4 TSI purely on the basis of fuel economy as the price was the same to lease with no premium for the diesel & as the performance of the 1.6 is fine for my needs it seemed like a win-win deal

What are people getting from their 1.6 TDI "blue motion technology" cars?.

My long term reading (by the car) is standing at 48.5 mpg which is 25 mpg shy of the published figures or around 32% less than it should be.

I know about the published economy figures & I should get within 10% of these seeing as I drive carefully. Will the engine "loosen up" enough to affect the fuel consumption figures enough to bring it up to where it should be ................ I don't think so !

The car is great to drive & the tech stuff fitted does make things easy but this fuel consumption/regen business is starting to annoy me & I get the feeling the dealer is going to stonewall me tomorrow (may be wrong though !)

Previous car was a 61 plate QQ diesel that had none of this regen stuff going on.

I have to say I wonder whether leasing a diesel was the right move unless you do high mileage journies.

Journies of about 7-8 miles the DPF is never going to get hot enough to passively work.

I still think its early days with only 500 miles in total on the clock as well.
I assume rightly or wrongly you don't do that a high mileage as you posted you were' not far from what you hoped for at 54mpg ' ( at 350 miles ) a couple of weeks ago.

I personally don't think you will get much joy from your dealer at this early stage.

[dcdick]

I have to say I wonder whether leasing a diesel was the right move unless you do high mileage journies.

Journies of about 7-8 miles the DPF is never going to get hot enough to passively work.

I still think its early days with only 500 miles in total on the clock as well.
I assume rightly or wrongly you don't do that a high mileage as you posted you were' not far from what you hoped for at 54mpg ' ( at 350 miles ) a couple of weeks ago.

I personally don't think you will get much joy from your dealer at this early stage.

I personally disagree with the "high mileages only" for diesels..............all taxis/delivery vans etc... are diesels & most of them are "stop start" journeys that are quite short mileage wise.
The mpg figure is worsening, it could well be due to the filters are using extra fuel on the "clean" cycle & if what you say about the DPF needing such a long time to reach operating temperature is correct then I find this unacceptable.
I did ask about this when choosing the car & was assured that unless I did a lot of very short journeys of "less than a mile or so" there would be no problem with DPF etc... & "anyway the car will just run through a cycle automatically if needed"

"Early days with only 500 miles" possibly, but the economy is never going to improve by 30% with some more miles on is it ?

Well, we'll see what the dealer has to say about this later today......... I'll post up what happens

Something is not correct here & needs addressing

[vc-10]

Yes, the DPF will use fuel when regenerating. I wonder if it's the typical VW issue of bad injectors as was mentioned in the 2.0 TDI thread?

[dickt]

I agree about excessive regens in the early miles. For what it is worth, my 2.0/150/GT did excessive regens for about the first 2000 miles. It maxed out at 3 in one day with only short journeys. As I reported elsewhere, this negatively impacted mpg. I talked to VW customer service, who said I should book it in at a main dealer for a complete computerised check. The dealer did not want to do the checks and was unpleasant. However, they must have done something, as since then the regen frequency has reduced, and the mpg has gone from 41/42 to 45/46. At last this new 25k car is doing the mpg that my Mk 5 2.0/170/dsg did with ease, after VW replaced both the regen kit and all the injectors. If they did not do anything - and maybe they did not even do the checks, maybe the engine settles down after 2,000 miles or thereabouts.

[maisbitt]

I agree about excessive regens in the early miles. For what it is worth, my 2.0/150/GT did excessive regens for about the first 2000 miles. It maxed out at 3 in one day with only short journeys. As I reported elsewhere, this negatively impacted mpg. I talked to VW customer service, who said I should book it in at a main dealer for a complete computerised check. The dealer did not want to do the checks and was unpleasant. However, they must have done something, as since then the regen frequency has reduced, and the mpg has gone from 41/42 to 45/46. At last this new 25k car is doing the mpg that my Mk 5 2.0/170/dsg did with ease, after VW replaced both the regen kit and all the injectors. If they did not do anything - and maybe they did not even do the checks, maybe the engine settles down after 2,000 miles or thereabouts.

Dealership technical remap most likely - went through this with my 2007 170TDI MK5 Golf. I really thought they'd nailed this as my 2 TDI Sciroccos (both with DPF) have been no bother at all.

[maisbitt]

I personally disagree with the "high mileages only" for diesels..............all taxis/delivery vans etc... are diesels & most of them are "stop start" journeys that are quite short mileage wise.

High mileage for diesels, maybe not, but significantly lower than average mileage for diesels is a valid point. I'm not talking about people disregarding the choice of diesel by saying things like "you'll never get your money back unless you're doing 20k miles a year" etc.

It is all about the DPF. You need a decent journey length a few times a week for the DPF to unclog. You've had your car for almost a month now and one of your first journeys was a 90 mile round trip, so you've averaged 18 miles a day excluding that one trip (for 550 miles total on the clock). If you're doing 5 miles here and 6 miles there on every trip then the DPF won't be getting a passive workout and will be trying it's best to do a forced regen a lot of the time you're out in it.

The argument doesn't apply to taxis as even though they do lots of short journeys, those journeys are accumulative - the taxi's engine doesn't have time to cool down between trips and so passive regen is going on all the time.

Forced regens make the car thirsty for those trips it's happening on. If the car is trying to go through on on nearly every trip then your mpg is going to suffer quite badly.

I don't think your situation with mpg will improve without intervention. If my assumption about your journeys is incorrect e.g. you do that mileage by fewer and longer trips rather than using the car daily and you regularly go at least 10 miles on a single trip doing motorway speeds (to get the engine temp up for a good few miles before your journey finishes) then the car is the problem, not your driving habits. In that case VW might be able to perform a warranty remap. Initial teething troubles with DPFs on TDIs are sorted for the 2.0 unit, not sure whether the same stands for the 1.6 unit.

The suggestion to remove the DPF is a no go. VW can supply non-DPF cars to certain markets whose legislation allows it, but trying to remove a DPF system already in is a tall order that VW officially say cannot be done. It is so tightly integrated into the fuelling/engine management and exhaust systems that removal will be quite costly to have done independantly and will probably render your VW warranty useless for any engine issues you may have in the future.