Diesel city driving anyone?

[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.

[kaanage]

yeah, I've come to the conclusion that I need to install a boost and EGT gauge to get the full picture of what's going on under the bonnet.

'accelerator' just seems such a cumbersome term after 'throttle' which is probably why most people still talk about 'throttle' when discussing diesels.

[MW103DSG]

I have a 2.0 Golf TDI and do a lot of reasonably short trips - about 15 minutes but some longer trips on weekends. What sort of additives do you put in with the diesel.

Cheers.

[Transporter]

I have a 2.0 Golf TDI and do a lot of reasonably short trips - about 15 minutes but some longer trips on weekends. What sort of additives do you put in with the diesel.

Cheers.

From Supercheap: Fuel Doctor, LiquiMoly, Moreys Diesel Engine Smoke Killer, Lucas Injector cleaner and upper cylinder lubricant.
From Repco: LiquiMoly

I use WURTH CRD Additive if you have DPF and Diesel Additive without DPF. All above are good I use them.

[Greg Roles]

Can I just point out that this is only a problem for those with a DPF, such as the MkV GT TDI, and the newer MK6 diesels. Other diesel vehicles such as Jeep, Peugeot, Skoda and the like had DPFs fitted in the last few years but I haven't kept up with other brands. If you drive a MKV 103kw TDI, you don't have a particle filter in the exhaust, and it comes down to economy and possibly consideration of those following!

[Transporter]

Good point Greg. But for these car owners who keep their without DPF car longer than 3years, maintaining injectors as clean as possible will be beneficial too, since dirty injectors will disturb injection pattern, which will lead to more unburned fuel polluting the oil in the crankcase, wearing out engine prematurely and more blow by gases with sludged oil will enter intake system.
Always use a good diesel additive it will pay for itself.

But for these who trade in when 3 years are up, don't worry too much about it, do what the owners manual says in regard to maintenance.