Diesel city driving anyone?

[Horse]

Does anyone drive their diesel mainly in the city? Is diesel/city driving as problematic as everyone on the forums say it is?

I'm trying to choose between a TSI Polo and the slower TDI. After testing both I preferred the TDI which seemed smoother in stop/start traffic and generally more enjoyable to drive than the petrol TSI. The diesel seems to better suit my conservative driving style.

The catch is that 95% of my driving will be in heavy Sydney traffic and suburban streets with many 10-30 minute trips and just the occasional longer trip on a motorway. The general consensus on the forums seems to be that, for many reasons, this type of driving is better suited to the petrol engine.

So, despite all the advice to the contrary, has anyone out there chosen to drive a diesel in the city without regular long hauls? How's it going?

[Greg Roles]

The main problem is your DPF. It likes to get hot, and it gets hot on longer, higher speed runs. They seem to clog by 100k worst case, and are expected to last 150k according to VW. If you intend to keep the car longer than this, it's a concern, if not, then don't worry about it. Also, if it's a manual, you can drive to suit, keeping the revs over 1800, below which you're producing a lot of soot when you put your foot down. I tend to drive in 3rd in the city / below 60kph in hills to keep the revs up and the soot minimal, and it does feel weird. The diesel has the catch 22 in that it will pull from down low, but soot itself whist doing so, and it ends up in the DPF. as this soot is never 100% removed, and slowly builds up, it's only a matter of time. Finally if you fit a Provent from new to minimise the oil blowby, which again ends up in your DPF as well as clogging up the intake, you stand the best chance of prolonging your DPF's lifespan.

[Transporter]

Four cars here with the diesel, two with the DPF, no single problem with the DPF especially in the Touareg that is driven mainly in the city and in the last almost 2 years km daily trips to the bus stop. We use only BP diesel with the highest CN and fuel additives in every tankful.

[Greg Roles]

Yep the great fuel and additive would DEFINATELY help. Good point Miro.

[Horse]

Straight to the point Greg, thank-you. And just the sort of experience I wanted to hear Transporter.

I seem to be faced with a choice between a Polo TSI that is cheaper, faster, less finicky with fuel and doesn't require additives, lets me put my foot down when under 1800 rpm without ill effect, doesn't require an add-on Provent filter and doesn't have an expensive DPF that requires regular regenerations and eventual replacement at 150,000kms. Against all this is a Polo TDI that I think simply drives better.

My brain says petrol but the heart says diesel. My heart usually wins but often I regret it later... reminds me of my wedding.

I must let the dealer know what I decide this week. He's been very patient. Then it's my turn to be patient while I wait for delivery. Hope the old car lasts that long.

[kaanage]

I see my Polo choking up if I don't get a Provent on it quicksmart as I tend to shift at 1500rpm (albiet only when running very light accelerator - is there a better word that is the equivalent to "throttle" for diesels?).
I do delay shifts if I sense the car is loading up but I generally drive on minimising the instantanous fuel consumption reading and rarely go above 2200rpm when commuting.

I was told that my car blew a fair bit of smoke on a cruise when I gave it lots of accelerator and revs.
At least mine is the older model without the DPF so no worries about that.

[Greg Roles]

Straight to the point Greg, thank-you. And just the sort of experience I wanted to hear Transporter.

I seem to be faced with a choice between a Polo TSI that is cheaper, faster, less finicky with fuel and doesn't require additives, lets me put my foot down when under 1800 rpm without ill effect, doesn't require an add-on Provent filter and doesn't have an expensive DPF that requires regular regenerations and eventual replacement at 150,000kms. Against all this is a Polo TDI that I think simply drives better.

My brain says petrol but the heart says diesel. My heart usually wins but often I regret it later... reminds me of my wedding.

I must let the dealer know what I decide this week. He's been very patient. Then it's my turn to be patient while I wait for delivery. Hope the old car lasts that long.

...but on the upside there's the fact you can go insane distances between fuel stations, flogging it doesn't really alter that too much, and there's that mountain of torque, albeit brief, right where you need it in normal driving. I chose the diesel because of the drive, and found out about all the "other stuff" along the way, but the torque is what sold me hook, line and sinker.

If I listened to my brain I would have bought a Honda Jazz, and been miserable for the rest of my life.

[poyta]

I drive my Golf GT TDi almost exclusively in traffic. I did initially have a lot of issues with the DFP clogging up requiring a regen often but I took it back to the dealer and they installed some kind of new ECU setting thats more suited to city driving - don't know the details but something about it regenerating itself more often rather than waiting till the DPF gets clogged. Anyway whereas before I had to do a proper regen once a month ( trip down the highway ) I now have only had to do this once in the last year and this was only because I got caught in a traffic jam that had me crawling along for 2 hours. You may want to ask your dealer if they have any settings or maps available that are more suited for city driving.

[Horse]

I really appreciate all your remarks guys, helped me a lot.

Poyta's positive experience with new ECU settings that were better suited to city driving finally tipped me over the line.

Savanna Yellow 66TDI Polo Comfortline DSG, contract signed.

[kaanage]

I'm sure you won't regret it. I should have stated that I have found my older Polo TDi to be a terrific city/suburb commute vehicle and very capable on the highway when needed. It's also a lot more fun to drive (fast and slow) than I had expected.
Your new one should be even better in most respects.

[Greg Roles]

Welcome to the gang!

[kaanage]

keeping the revs over 1800, below which you're producing a lot of soot when you put your foot down. I tend to drive in 3rd in the city / below 60kph in hills to keep the revs up and the soot minimal, and it does feel weird.

Yo're not kidding about it feeling weird. I 've tried driving like this for the last 3 commuting runs since reading your post and it just feels wrong. Not using the torque available from idle seems like neglecting the capability of the engine and being an older non-Piezo PD it's a lot more raucous and more obviously diesel.

I feel like the anti-hoon legislation was targetted at me as the car is so eager to accelerate above 2000rpm. Also, fuel consumption has gone through the roof (about 20%-30% higher than with my 'Bluemotionesque' driving style).

From this point of view, the newer 1.6L TDi ought to be easier to drive in this manner as it will have noticably less torque off idle.

[Greg Roles]

Don't get me wrong, you can indeed spend the majority of time in 4th at 60, just avoid putting you foot down a lot, change down instead. Its all about avoiding big throttle off boost, in higher gears where it remains off boost for a while. Taking off from the lights you are obviously below 1800, but its only for a moment. If you are going up a big hill in 4th at say 50k and you accelerate hard, it will labour for many seconds trying to get on boost, and it's sooting like crazy. In a way it would be a good idea to drive a non DPF diesel, just to learn where the soot is mainly produced, and to avoid those combinations as much as possible.

I think I've lead you up the garden path a bit Kaan!

The problem with a DPF is you can't see when you're filling it up, and in doing so, you shorten it's life!

[kaanage]

More a case of me taking you too literally, Greg, I think.

My normal driving style is to use minimal "throttle" (we still need to find a more appropriate word) in high gears, right down to idle, with downshifts as soon as I'm using more than about 1/10th of the accelerator travel (blatant guesstimate). It's my interpretation of the Bluemotion change indication system based on the instantaneous fuel consumption readings.

I do this as much to keep myself from getting bored as much as for the fuel economy but I must be sooting up to some degree based on the smoke the others saw during our weekend cruise. Or maybe it was the build up of EGR gunk getting flushed through. Either way, it would be bad if the car had a DPF

My wife seems to get fairly frequent DPF regens with our DSG CR Golf VI so the D mode shift programming (I can tell you she isn't going to manual shift it) must be doing the same thing. Incidentally, I get far better mileage then she does when I'm driving the Golf, even though I'm the male hoon

(Another) Greg

[gldgti]

kaanage - ye olde diesel literature commonly uses the term accelerator, which is quite correct as its function is to accelerate the engine speed when depressed.

I could only add to the conversation that a simple boost guage is a good way to understand in real time the way your accelerator input relates to the turbochargers response. In a diesel, you can learn a lot about how the engine deals with load changes and fuelling changes just by keeping one eye on the boost guage.

As an example, any time where the boost guage reponse lags behind the cars acceleration, you know you are likely to be making some soot.