Mazda 6 - Mazda Diesel or Petrol and DPF questions - MazdaManOrNot

Hello, I ned some advice because I've read conflicting info. I am thinking of getting a diesel mazda 6 but have read a post on here about the DPF issues with the Mazdas but I have also read that it's DPF's in generall that are an issue.

So I have a few question to help clear things up.

To prevent DPF issues, do I really just have to take it on the motorway for 10mins a week? I usually do a long trip each week anyway.

In regards to Diesels and damaged caused by short journys, what is considered a short journey?

Thank you for any advice, it's really appreciated!

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76
It takes longer than a ten min drive at motorway speeds to trigger a DPF burn cycle normally so unless you're doing several longer journeys a week then a diesel equipped with one simply isn't suitable for your usage.

You also don't mention your budget. Are we talking about £3,000 here or £30,000? The previous gen 6 uses a PSA 2.0 diesel that's generally ok aside from the usual DPF issues but the later Mazda Skyactiv-D 2.2 units are known to be problematic with many high profile failures to date. The petrol versions are proving to be as reliable as Mazda petrol engines historically always were and economy isn't bad for such a large car but they do lack midrange urge without a turbocharger. As a used purchase I'd leave the diesel and buy the petrol on one of these.
Mazda 6 - Mazda Diesel or Petrol and DPF questions - Stanb Sevento

My personal opinion is that there is a bit of an over reaction to DPF scare stories. Ive had 4 diesels with DPF and never had the slightest issue with any of them I fact I ran a 2.0L Touran for 38000 miles before even knowing it had a DPF. Things dont stand still and design is improving all the time, modern DPFs bolted straight onto the cylinder head run much hotter than older models that were under the floor so will regenerate more easily. The Masda 6 uses "manifold in head" so gets up to temperature very quickly eliminating a big source of soot production. At the same time methods of clearing ash from DPFs are also getting better, £350 to £600 after 80 to 100K miles is not that bad in the scale of things.

What is a short journey? I would say one where the engine fails to get up to temperature, 75*C in my case. So in winter its longer than summer, 6 miles to 3 miles I would estimate. I know if I do 6 or 8 journeys of 3 or 4 miles the next time I drive the car will go into an active regen for about 10 minutes at any speed above 38mph. High revs or high speed are not required for a routen DPF regen because the heat required is provided by extra fuel in the manifold not by the normal exhaust gas. Provided you let it complete there are no issues, its only if you repetedly switch of during a regen that the problems start. Again in my personal experence premium fuel like V Power + Nitro seems to have cut down my regens dramaticaly. I drive a lot in a 50mph limit in 6th gear and the car is perfecty happy with that, many hundreds of miles between regens. Im quite optimistic about diesel.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - skidpan

To prevent DPF issues, do I really just have to take it on the motorway for 10mins a week?

A DPF will only regenerate when the ECU tells it too. The ECU does not know you are on a motorway. All you will achieve by driving needlessly on the motorway is to waste fuel and money.

The answer is simple, buy a petrol. A modern small turbo petrol such as the VAG 1.4 TSi drives in a very similar manner to a diesel, is very economical and has no DPF.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - MazdaManOrNot
They are nice but out of my price range. I was thinking around 3-4.5k and the older models don't seem to have those bonuses although I might be wrong, I've never delved this deep into cars before.
Mazda 6 - Mazda Diesel or Petrol and DPF questions - Stanb Sevento

A DPF will only regenerate when the ECU tells it too. The ECU does not know you are on a motorway. All you will achieve by driving needlessly on the motorway is to waste fuel and money.

Thats not srictly true skidpan. On modern diesels the majority of soot is burned off by normal driving with no input from the ECU, its only when the soot loading goes above a specified level as measured but pressure sensors that an active regen is triggerd by the ECU. Only around 10 to 15% of my driving is in town with the rest on rural roads 40 to 60 mph but fairly steady speed and I go weeks between active regens, over 2000 miles in one case. I get the feeling if I only did open road driving I would never get an active regen.

I do agree that for many petrol is a better choice, the gap has narrowed a lot in how they drive, their price is lower and they are fine with a lot of town driving. Mine is a big heavy car and the 1.4 TSi feels feeble compared to the diesel but in a smaller lighter car even for me a petrol would win.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - MazdaManOrNot
Thank you for such a detailed answer. This raises another question though, if I was to do a short journey, could I just leave this the engine running for a few minutes before setting off, To get the temperature up?
Mazda 6 - Mazda Diesel or Petrol and DPF questions - Stanb Sevento
Thank you for such a detailed answer. This raises another question though, if I was to do a short journey, could I just leave this the engine running for a few minutes before setting off, To get the temperature up?

Sorry thats not a good idea, letting it run when cold generates a lot of soot and the DPF has more work to do.

You dont say what sort of driving you will be doing but if you are worried you usage may be less than ideal for a diesel then I hate to admit it but petrol could be your best bet.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - RobJP
Thank you for such a detailed answer. This raises another question though, if I was to do a short journey, could I just leave this the engine running for a few minutes before setting off, To get the temperature up?

NO !

Modern engines - especially efficient diesels - don't generate lots of heat until they are actually doing work, and idling isn't doing work. The engine will warm up really slowly if just left on the drive idling, and all that time it's trying to warm up by over-fuelling, which turns into more 'gunk' (which is more likely to lead to a clogged EGR valve), and more soot, which will clog up the DPF sooner.

Buy a modern DPF-equipped diesel ONLY if your journey types are suitable. Don't try to 'bodge' round it, it will only end in tears and a big bill.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76
Agree totally with above comments. It sounds like your usage is not compatible with a DPF equipped car. Go for a petrol model for lower overall running costs or seek out a diesel without a DPF. At your budget though It would be unwise to go for a diesel.

If you simply must then a Kia Cee'd or Hyundai i30 1.6 diesel didn't have a DPF as standard until 2011, though apparently some late 2010 cars did. Honda's 2.2 CTDi never had one either, but the later 2.2 DTEC does, though this would be out of your price range anyway.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - skidpan
If you simply must then a Kia Cee'd or Hyundai i30 1.6 diesel didn't have a DPF as standard until 2011, though apparently some late 2010 cars did. Honda's 2.2 CTDi never had one either, but the later 2.2 DTEC does, though this would be out of your price range anyway.

ALL MY 2011 Kia Ceed CRDi's had a DPF, no excepetion. They were imported from September 2010. No MY 2010 Kia Ceeds were imported after July or August 2010. Some MY 2010 may have been registered in 2011 but they will be very rare and should have been crushed and the dealers prosecuted (but thats another story). Look at the V5C, if it says Euro 4 no DPF, Euro 5 DPF.

But don't forget that the unloved and unpopulat Ceed 2.0 CRDi had a DPF from 2007 to its deletion in 2009/10. It was rare and horrid so ignore it at all costs.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76
We've been through this before skidpan, I even emailed Kia customer services and called our local dealer for an answer on this and they stated there were a number of Cee'd's registered in 2011 without a DPF. Kia and Honda both obtained an extension to continue registering cars into 2011 which were already built and in the country because it wasn't possible to meet the deadline. Purely out of curiosity since our last debate on this subject I've looked at several 2011 registered Cee'd's, Rio's and Civics which had no DPF fitted including one 61 plate Cee'd. Not sure what other manufacturers did the same but no doubt there will be others. This is fact and I'm not interested in entering another argument over it.

To suggest the car should be crushed and the dealer prosecuted is plain idiocy. Think of the economic damage that destroying a brand new car would do and think of the economic damage it would've done to dealers and manufacturers. We are trying to portray the UK as business friendly after all so a little flexibility regarding new legislation was just common sense.

But yes the majority of 2011 Cee'd do have a DPF fitted. Some, and more than a handful do not however.

Edited by SLO76 on 10/04/2017 at 13:27

Mazda 6 - Mazda Diesel or Petrol and DPF questions - skidpan
We've been through this before skidpan, I even emailed Kia customer services and called our local dealer for an answer on this and they stated there were a number of Cee'd's registered in 2011 without a DPF. Kia and Honda both obtained an extension to continue registering cars into 2011 which were already built and in the country because it wasn't possible to meet the deadline.

Being an untrusting soul and knowing exactly what the requirements were for the implementation of Euro 5 in January 2011 and also knowing that when we ordered our Ceed CRDi in August 2010 there were very few stock cars available (none in our colour) and that all cars imported from September 2010 had DPF's fitted in readyness for Euro 5 I decided to pose as a buyer of a Ceed CRDi and asked Kia Customer services a simple question.

Basically I asked if any new Ceeds registered after January 2011 were sold without a DPF.

The reply I recieved form Kia Customer Services today reads:

Dear Mr Skidpan

Thanks for your email.

I can confirm that we didn't sell any diesel vehicles without a DPF after summer 2010. This is to comply with the requirement to have filters on all new vehicles.

If you'd like to purchase a Kia without the required DPF filter, you'll have to buy an older one without warranty.

This is exactly what I expected and proves beyond doubt that I have been correct all along.

Perhaps I should contact Honda now.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76

Here's some of those offending 2011 registered Kia's you say don't exist. Feel free to pop along and look for a DPF at your leisure. You won't find one. Auto Trader: www.autotrader.co.uk/classified/advert/20170217240...6 Auto Trader: www.autotrader.co.uk/classified/advert/20170401393...7 Auto Trader: www.autotrader.co.uk/classified/advert/20170410427...2 Auto Trader: www.autotrader.co.uk/classified/advert/20170326369...2 Auto Trader: www.autotrader.co.uk/classified/advert/20170317338...4 And a few invisible Honda's for good measure again with no DPF fitted... Auto Trader: www.autotrader.co.uk/classified/advert/20170403402...6 Auto Trader: www.autotrader.co.uk/classified/advert/20170326369...6 Auto Trader: www.autotrader.co.uk/classified/advert/20170408422...2

Edited by Avant on 12/04/2017 at 00:41

Mazda 6 - Mazda Diesel or Petrol and DPF questions - Avant

I've deleted any suggestion that someone wasn't telling the truth.

I'm struggling to understand why this issue is so vital to have generated so many column inches. No doubt Kia sold their last non-DPF diesels to dealers in 2010 but some of them lingered on the forecourt till 2011.

Edited by Avant on 12/04/2017 at 00:43

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76
It is tiresome, everytime the subject of buying a late first gen Cee'd or eighth gen Civic diesel crops up the same argument happens. I've spent time on this and had answers both from Honda and Kia stating that some cars were registered in 2011. As a trader, it's vital I know what possible liabilities are lurking under the surface of any car, profitability especially at the sub £4k end of the market is very dependent on doing my homework. Anyway, right enough Avant, too much time has been spent on this. Apologies if dishonesty was suggested but seems odd that Kia customer services are telling me one thing and my good friend another. Every possiblity it's down to staff simply not knowing their product.
Mazda 6 - Mazda Diesel or Petrol and DPF questions - skidpan

I've deleted any suggestion that someone wasn't telling the truth.

I'm struggling to understand why this issue is so vital to have generated so many column inches. No doubt Kia sold their last non-DPF diesels to dealers in 2010 but some of them lingered on the forecourt till 2011

Thanks for editing the post. If the other poster has a problem with the content of my post it should be addressed to Kia and not responded to by suggesting I was not telling the truth. I have 100% confidence in the information provided by Kia, if he considers Kia did not supply true information it should be escalated up the customer service tree at Kia.

Avant, you are correct that some non-DPF Ceeds remained unsold into 2011 but they were pre registered before the end of 2011 to avoid non-compliance with the EU5 regs. When we ordered our Ceed in August 2010 the dealer had one unsold car in stock without a DPF (EU4 spec) in the spec we wanted but it was metallic red, a colour I will never buy again. He did a search for a nother colour and no cars were available. We ordered a factory car in Silver which was delivered in September to EU5 spec with a DPF. Obviously many other locals have the same aversion to red as we do since it remained unsold and was pre-registered as the law required eventually selling in the spring. It was probably a year old by then.

Mazda 6 - Mazda Diesel or Petrol and DPF questions - SLO76
I think it's easy to put this one to bed. From now on whenever this crops up I'll suggest the OP uses the registration number of any car Rio, Cee'd or Civic they're looking which was registered in 2011 and ask the question of Kia or Honda customer services directly. Life's too short for squabbles.
 

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