Diesel cars with DPF are NOT good town cars

[ahuxham]

Your mate is lying. There's no way that he's getting 50mpg in a 2 litre petrol, unless it's downhill the whole way.

 

And what diesel car do you have? You should have checked the car's figures before buying it.

 

48.2 MPG here 1.6 Petrol, and very happy to use the loud stick

[TwoZeroAlpha]

Averaging 48.9MPG at the moment, Seat Leon Cupra TDi, and that's not exactly hanging about, so much better than my Ford Puma that got 35ish MPG when I drove like a nun.

 

I like Diesels, I like the torque, the economy and the easy cruising power. It'll take a lot to get me back to petrol.

[3s-gtech]

My petrol car dreams of 30mpg, that's 2.0. Heavy driving, 10mpg isn't difficult, and it's running properly! My old battered diesel runaround gets 45mpg, my girlfriend's 1.2 petrol gets 30mpg, slightly lighter driving style. I wouldn't run a petrol car as a daily on my wages

[CHR1S]

Bluemotion and Bluetec are aerodynamic packages, narrow tyres and modified injection/combustion techs. The Urea idea is only being applied in trucks atm, most car manufacturers are persuing the electric/hybrid route rather than combustion techs.

 

Ahh right, I just had a quick search and found that there is quite an infrastructure in place for this AdBlue stuff already.

 

Air1 - AdBlue Filling Stations

 

Do you just mix it with your diesle in the tank?

[broc]

I have a Mitsubishi Colt Di-D. It's only got 95 bhp, but then it only weighs 930Kg, so that's over 100bhp per ton.

 

Hmm... my X-Trail tips the scales at 1525kg & at 173bhp that equates to 115 bhp per ton

 

I must admit I like the torque of diesel engines too, and being able to drive all 4 wheels can be handy at times.....

[Gonk]

Ahh right, I just had a quick search and found that there is quite an infrastructure in place for this AdBlue stuff already.

 

Air1 - AdBlue Filling Stations

 

Do you just mix it with your diesle in the tank?

 

no, the Urea is held seperately and injetced. It only works if you have a SCR compliant vehicle. [ame=http://en.wikipedia.org/wiki/Selective_catalytic_reduction]Selective catalytic reduction - Wikipedia, the free encyclopedia[/ame]

[sacrej]

Eek, my folks are looking at getting a Citroen HDi on motobility. There pressent motability car has done less then 20k in 3 years. I think I'll have to do some digging.

 

My mums got an 04 C3 1.4 hdi, brilliant little car - i'm actually looking at upgrading from my C1 1.0l to a new style C3 1.4 diesel or petrol

[CHR1S]

no, the Urea is held seperately and injetced. It only works if you have a SCR compliant vehicle. Selective catalytic reduction - Wikipedia, the free encyclopedia

 

Quite interesting reading, especially the bit about why so much heat is needed to break the nitrogen bonds and obviously the need for the catalyst. Seems its exactly the same issue as with the particulate filter in which it needs the high temperatures to work.

[Gonk]

@CHR1S:

 

Yeah, the chemical reaction needs a lot of energy put in to get it to go as it were, however, its possible, as DAF have achieved it at a sensible cost.

 

The only reason they don't have the SCR system on cars is:

 

Where to put the urea tank?

Will Joe Public pay the money to refill the urea tank?

Can it be refiled as a service operation - i.e refill at each service? (service interval of 15 - 20k miles on a Citroen petrol these days, so I'm informed)

Can enough be stored on the car to get it from one service to the next?

 

everyone knows that it will help if we have a SCR system, the problem as always is will we pay for it and is it a long term solution?

 

Ross

[fafster]

Yep it sure is

 

@fafster: is it the 1.5 DI-D? the 1.5 is a Mercedes Benz unit that was used in the A-Class/Smart range. There's a lot of scope for rermapping and modding from what I recall.

 

Yeah, 1.5 MB engine. The colt can take a lot of Lancer kit, too, apparently.

[ZeroHour]

I have an RX8, best not talk about fuel economy then I thinks

[ahuxham]

I have an RX8, best not talk about fuel economy then I thinks

 

Or oil economy as a matter of fact

[Gonk]

I had an RX-8 for a while.

 

They're great fun but as ZH says 23mpg is a little low!!

[CHR1S]

Beat me to it ahuxham! lol

[alan-d]

For around £700-800 you can get the DPF removed. If you work out how much extra fuel you use to clear the DPF over the time you intend to own the car it may pay for itself.

 

On some cars - the removal of the DPF actually improves performance and mpg. The DPF is not a legal requirement.

[michael2k6]

I've got a 58 Mondeo 2.0 TDCi and how that works is an element in the DPF - if the exhaust gets hot enough it sorts itself out, if it gets to 500 miles without it doing it, at the 500 mile point, the element kicks in and causes regeneration.

[broc]

The problem with any DPF regeneration process is it takes time, I am told 10-20 minutes depending upon engine speed; if the ECU decides it's time for a regeneration 30 seconds before you arrive at your destination it will fail. If your next few journeys after that are short trips with the system never getting enough time to clear the filter you can be easily caught out as the ECU counts down to turning on limp-home mode & then you are into dealer regeneration, I have seen sums of up to £200 mentioned for the dealer to regenerate the filter & many treat it as driver error & refuse to perform regeneration under warranty without a fight.

 

It looks like I cannot risk using 6th gear on my car for my normal commute anymore. Ridiculous!

 

Someone should take Nissan to task with the advertising standards authority over their 'urbanproof' Quashqui ads.... clearly not applicable to their 2.0 diesel versions

Edited March 24, 2010 by broc

[ahuxham]

The problem with any DPF regeneration process is it takes time, I am told 10-20 minutes depending upon engine speed; if the ECU decides it's time for a regeneration 30 seconds before you arrive at your destination it will fail. If your next few journeys after that are short trips with the system never getting enough time to clear the filter you can be easily caught out as the ECU counts down to turning on limp-home mode & then you are into dealer regeneration, I have seen sums of up to £200 mentioned for the dealer to regenerate the filter & many treat it as driver error & refuse to perform regeneration under warranty without a fight.

 

It looks like I cannot risk using 6th gear on my car for my normal commute anymore. Ridiculous!

 

Someone should take Nissan to task with the advertising standards authority over their 'urbanproof' Quashqui ads.... clearly not applicable to their 2.0 diesel versions

 

Why not do that? Then when you get correspondence and the dealer/garage aren't doing anything about it under warranty, show them the correspondence and add them to future mailings to trading standards, showing the affect of the false advertising and the need to spend more money on something that should work, and was advertised as working.

 

We're you made aware during sales, or did the manuals state the DPF function doesn't work as advised when using it for short trips? If not, there is clearly a case, and guaranteed, if spoken to the dealer/garage about it, they wont quibble about getting it fixed without cost

[bondbill2k2]

Revival of an old topic here this came up as a similar thread to the old cars one and funny enough this week I've been looking at a few cars mainly 170PD and CD TDI engines which all come with DPF's and researching into the cars I've found so many people complaining about DPF issues, mixed reports on the rumor of long driving makes a difference as the DPF re-gen could kick in after the long drive and stupid pricing from dealers to simply force charge. Near half of these reports ended up being false sensors sticking at a % and stopping the DPF cycle finishing.

 

It looks like more recently alot of garages offer DPF removal service, completely cutting out the internals of the DPF and removing it from the ECU, others offer a bypass pipe to replace the DPF section of the exhaust. Both don't affect MOT's and providing you don't have heavy remaps shouldn't cause smoking

[jinnantonnixx]

Years ago, diesels were simple and reliable. I don't think that's the case anymore.

 

Frequently Asked Questions | Honest John

[witch]

Years ago, diesels were simple and reliable. I don't think that's the case anymore.

 

Frequently Asked Questions | Honest John

 

Depends what you mean by "years ago". We have had diesels since about 2000 and have had very few problems. The cars range from P reg through 55 to 10 so they span quite a few years. The oldest had new glow plugs once in its lifetime but that is about all.

[Flatpackhamster]

Revival of an old topic here this came up as a similar thread to the old cars one and funny enough this week I've been looking at a few cars mainly 170PD and CD TDI engines which all come with DPF's and researching into the cars I've found so many people complaining about DPF issues, mixed reports on the rumor of long driving makes a difference as the DPF re-gen could kick in after the long drive and stupid pricing from dealers to simply force charge. Near half of these reports ended up being false sensors sticking at a % and stopping the DPF cycle finishing.

 

It looks like more recently alot of garages offer DPF removal service, completely cutting out the internals of the DPF and removing it from the ECU, others offer a bypass pipe to replace the DPF section of the exhaust. Both don't affect MOT's and providing you don't have heavy remaps shouldn't cause smoking

 

This is odd. I'm now on my third Focus 2.0TDCi in 8 years. Each one has been brand new and I've done about 10,000 miles per year, at least half of which is short journeys around town. I drive economically and typically get just under 50MPG, and I keep the cars for around 3 years.

 

I have never encountered this problem. I'm sure the Focus must come with a DPF.

[jinnantonnixx]

This is odd. I'm now on my third Focus 2.0TDCi in 8 years. Each one has been brand new and I've done about 10,000 miles per year, at least half of which is short journeys around town. I drive economically and typically get just under 50MPG, and I keep the cars for around 3 years.

 

I have never encountered this problem. I'm sure the Focus must come with a DPF.

 

You're running your cars like a fleet does. Again, from Honest John

Diesels with particulate filters, dual mass flywheels and exhaust gas recirculation valves are best avoided. They only make sense for fleets that run them to 60,000 miles over two to three years on minimum maintenance, then sell them to the general public before any problems occur.

 

 

I've had an old-school diesel of one sort or another since the early '90s and they've been great to run - simple and reliable. My current van is a 2000 (Y plate) which has done 156k without a problem, but it's an old fashioned, non-turbo, unrefined old boat. I intend to keep it as long as possible!

 

Technical stuff about the DPF systems:

Frequently Asked Questions | Honest John

 

And if you're not convinced...

The biggest mistake of all is to buy a high mileage 3-year-old ex-fleet diesel car on the false assumption that diesel engines are robust enough to take the mileage and continue to offer fuel economy advantages. All too often, dual mass flywheels, diesel particulate filters, EGRs and turbos fail, potentially landing the car buyer with bills greater than the vale of the car.

The Which? study also considered reliability, taking information directly from the 2012 Which? Car Survey, which found that petrol cars are generally more reliable than diesels – both in the first three years of their life (the typical warranty period), and even more so between four and eight years-old.

Which? Confirms Hidden Costs of Running Diesel Cars | Motoring News | Honest John

 

But nobody has a crystal ball (that works), so you can only act on advice. Take it or leave it.

Edited August 31, 2013 by jinnantonnixx

[superatticman]

Diesels have their place, especially if you are up and down the motorway all day. However, around town, my comfy old 1999 3 litre Accord Coupe returns only slightly less fuel consumption than my previous MG ZT 2 litre diesel (which was running perfectly healthy

 

Large petrol engines tend to warm up extremely quickly and are efficient within minutes. The diesel was usually just getting to operating temp when I was pulling into the car park at work.

[Flatpackhamster]

You're running your cars like a fleet does. Again, from Honest John

 

Not really. I do change regularly, but I'm not doing fleet mileage and I'm doing an awful lot of around-town-pootling. Not saying the DPF stuff is wrong but it just doesn't gel with my experience.