DPF

[Lol6]

Good morning,

Anyone had any DPF issues with their Mk III?

[blahde2]

Other than the usual regens, no. But then I learned the hard way a few years ago by using supermarket diesel and my DPF didnt seem to like the flavour!

Fortunately the garage didn't question my DPF issue and just replaced it.

[Lol6]

My 150 tdi is on order.  I only use BP or Shell on my current Mazda 6.  Seems to work and goes better too.

[Rainmaker]

Personally, if I was running a diesel vehicle that I owned (rather than leasing/renting) I'd only use BP Ultimate. It's the only fuel in the UK (AFAIK) that doesn't contain fatty acid methyl ester (FAME) biodiesel, but rather uses hydrotreated vegetable oil (HVO). According to the internet:

 

Hydrotreated vegetable oils (HVO) do not have the detrimental effects of ester-type biodiesel fuels, like increased NOx emission, deposit formation, storage stability problems, more rapid ageing of engine oil or po or cold properties. HVOs are straight chain paraffinic hydrocarbons that are free of aromatics, oxygen and sulfur and have high cetane numbers.

 

As well as being better for the engine oil, it is also less taxing on a DPF than traditional FAME biodiesel. Apart from BP (and possibly Shell V-Power, which contains Perl GTL and may or may not also contain FAME) no other company omits FAME biodiesel from their diesel fuel. 

[Lol6]

Thank you for the information, Rainmaker.

Probably a little too late for my 90,000 mile and soon too be sold , (sadly), Mazda, but a thought worthy of a new car fo sure.

Perhaps there will be benefits in economy and performance as well. With oil in better condition for longer, I would hope so. I only use top quality oil and change it more frequently than the service intervals suggest, as with the fuel filter. The Mazda has been fantastic over ten years of mixed driving and I am hoping this mighty black best will be too.

[dstev2000]

I've had three Superbs with DPFs now, and I've always used either BP or Shell diesel with the odd tank of BP Ultimate slung in for good measure. 

 

I've never had any major issues with the DPFs on any of the cars, despite spending way too much time sitting in traffic. Lots of motorway driving probably offsets that and then some. 

 

The only issue was a duff pressure sensor that had to be changed, but that was an easy warranty job. 

 

Good quality oil is always helpful. The Ash content of oil is the one thing that a DPF can't burn off. This accumulates over the miles and eventually needs to be sorted out. We are talking easy six figure mileage here BTW! 

[maffyou]

In the 105k miles my Octy 2 has done, I've always filled it up with the cheapest diesel I can find - invariably the supermarkets bog standard - and I've had no issues with it.

Anecdotal evidence I know, but I struggle to see the benefit of an extra 5p+ per litre when I fill up...

[dan123]

I'm also on my third diesel Superb (a Mk 1, 2 and now 3) covering in excess of 160k miles.

I've always used the cheapest diesel (usually supermarket) and have never had any DPF issues.

However they have all been company cars so it's not my problem of I run into trouble!

Edited 2 August, 2016 by dan123

[psycholist]

DPFs only showed up on the more recent common rail engines, so the Mark 1 and quite possibly the Mark 2 didn't have one. I still tend to use whatever fuel is cheapest, unless it's suspiciously (As in bleached agridiesel) cheap. I don't expect to have any problems as a result as the engine is designed to run on fuel that meets the same standards as the fuel that's sold here is meant to meet. I always buy the fuel on credit card though as this means I have a record of where my recent fills came from if there is a contamination issue - which is as likely to happen with expensive brand name fuel as with cheap fuel as it often boils down to employee competence and it's not like most petrol station employees are highly trained...

[dstev2000]

The Mk2 had DPFs from the off, I think there was a non DPF engine in the form of the 1.9TDI PD105. The DPF setup on the 2.0TDI PD140 was a total lash up. PD engines aren't suited to the fuelling requirements of a DPF regeneration. The purpose designed systems on the 1.6 and 2.0 CR engines have been reasonably reliable, they came in around 2010 (59-60 plate UK) IIRC.

[philpix]

My 60 plate S2 has DPF. Run on bog standard Tesco diesel with no problems in 100,000 miles.

[teebs]

It's more the journeys you complete rather than the fuel used (although that will be a factor)

Short journeys don't allow the filter to 'burn off' the deposits, then it inhibits the regeneration process.

Given it takes a diesel a good amount of time to get to temp, it's easy for some people to go 4 weeks or more without getting to required temp.

My colleague had her filter replaced on a Vauxhall as she was only doing very short journeys in a 2.0 diesel. This was a 20k 64 plate Insignia.

Diesels used to be very popular as a used car, but the trade are shunning them a bit nowadays given the associated issues with various diesel related problems..small & medium turbo petrol engines are where it's at now.

[psycholist]

In Ireland where diesel can be 15 c a litre cheaper than petrol in some petrol stations (Usually more like 7-10c), something like 90% of new cars are still diesel. CR engines heat up very quickly compared to older diesels, so heat up time is less of an issue. Electric cars/plug-in hybrids with an all electric mode are a much better choice than internal combustion regardless of fuel for anyone doing lots of short trips though as the IC engine won't need to start at all for most trips - bicycles are an even better option if the trips are than short of course. VW petrol engines (And presumably all the rest too) are getting particulate filters from 2017 AFAIK, so DPFs won't be avoidable whichever fuel you choose. Petrol particulate emissions may turn out to be more harmful than diesel ones due to the particles being smaller (So they don't look obviously dirty, but small particles can interfere a lot more with biology than big ones).

[countryboy]

In Ireland where diesel can be 15 c a litre cheaper than petrol in some petrol stations (Usually more like 7-10c), something like 90% of new cars are still diesel. CR engines heat up very quickly compared to older diesels, so heat up time is less of an issue. Electric cars/plug-in hybrids with an all electric mode are a much better choice than internal combustion regardless of fuel for anyone doing lots of short trips though as the IC engine won't need to start at all for most trips - bicycles are an even better option if the trips are than short of course. VW petrol engines (And presumably all the rest too) are getting particulate filters from 2017 AFAIK, so DPFs won't be avoidable whichever fuel you choose. Petrol particulate emissions may turn out to be more harmful than diesel ones due to the particles being smaller (So they don't look obviously dirty, but small particles can interfere a lot more with biology than big ones).

Agreed about the particulates, petrol engines with direct injection will eventually have to have a DPF and as far as I am concerned all internal combustion engines burning liquid hydrocarbons will produce particulates. The lighter the fuel the lighter and smaller the particle matter. Diesels have a bad reputation because in the past you could actually see the particulates in the form of smoke. These can be breathed in, but as they are bigger then will get stuck in the upper respiratory tract where they have the possibility of being caughed up. Petrol particulates, being that much smaller will pass lower down and into the lungs, possibly into the alveoli where there is little chance of being removed and will interfere with gas transfer into the blood. Engines today produce well under 10% of the harmful emissions of engines from 15 years ago. 

 

Diesel used in agriculture is now the same as road diesel but the only difference is the dye being added as off road engines have to meet emissions standards using DPF and/or SCR.

Ian

[FelisBengalensis]

VW will start fitting GPF (Gasoline Particulate Filter) systems from next year on some of their engines.

[Rainmaker]

VW will start fitting GPF (Gasoline Particulate Filter) systems from next year on some of their engines.

 

Unfortunately so, yes. Do you happen to know which ones? The whole idea of fitting dual injection (port/MPI as well as direct) on the new gen3 EA888 2.0 TSI was precisely to avoid the need for a GPF to comply with Euro 6c, so I'm hoping the higher end models will be omitted. 

[FelisBengalensis]

All the article refers to is the 1.4TSI and 2.0TFSI as the starting engines as they are the 'dirtiest' with the Tiguan being done to start with and then a wider roll out. TUV Nord tests have found that modern direct petrol injection engines may emit up to 10 times the particulates of EU6 diesels (no mention of NOX levels), so a GDF being needed was bound to come sooner or later.

Indirect injection engines are much cleaner for particulates (up to 1,000 less) but bad for CO2 so you just can't win it seems.

Edited 7 August, 2016 by FelisBengalensis

[countryboy]

All the article refers to is the 1.4TSI and 2.0TFSI as the starting engines as they are the 'dirtiest' with the Tiguan being done to start with and then a wider roll out. TUV Nord tests have found that modern direct petrol injection engines may emit up to 10 times the particulates of EU6 diesels (no mention of NOX levels), so a GDF being needed was bound to come sooner or later.

Indirect injection engines are much cleaner for particulates (up to 1,000 less) but bad for CO2 so you just can't win it seems.

That will always be the case no matter what fuel you burn, hence diesel engines either having EGR and DPF to lower combustion temperatures and contol NOx that way and reduce the resultant particulate production with the fliter, or have SCR, let the engine burn hotter to reduce particulate matter and lower the resultant high NOx production using the SCR/adblue. Now petrol engines are starting to use the direct injection to increase efficiency they are beginning to show the same problems that diesel engines have shown for many years and will have to use similar technology to clean up their act.

Ian