DPF and Performance Tuning: Is it Worth It?

I was wondering what your opinions are on retrofitting Diesel Particulate Filters (DPFs). Specifically, should they be installed, especially in relation to engine tuning? I mean, you often hear that they can become clogged, and a diesel engine that has been chipped will likely produce more soot than one that hasn't. I don't plan on retrofitting them for cars manufactured before 2009, but after that, it will probably be necessary, and I'm already dreading it. What are your thoughts? What are the opinions on this? Best regards.

Hello.
Basically, yes, although the blurring of the tuning has a very significant influence here.
If the tuner is sunk too deeply into the smoke limiter, the engines will produce excessive smoke, which can lead to significant problems with the retrofit filters .
These can then, in some cases, no longer regenerate properly. Furthermore, the exhaust gas temperature during tuning with IDR is significantly higher, which can lead to overheating and thus to the destruction of the DPF .

At HJS, for example, the warranty is void if the DPF is installed on an engine that has been modified.

In your case, I wouldn't install a DPF without first checking your software.
We still don't know exactly how much extra power is programmed into your device.

Ulfs Lambda calculations look trübe (cloudy/unclear) with you, with either no change or only minimal changes to the LD (likely referring to a specific parameter or value).

If these values are confirmed, it doesn't look good for the DPF (Diesel Particulate Filter) under your vehicle.

Best regards,

In my opinion, a retrofitted DPF is a farce even on the original engine. The effectiveness of these systems is currently being heavily debated in public, with some cases even leading to lawsuits for damages, etc.

On a vehicle where the power has been increased, that would probably be the very last thing I would install. Instead, I would try to remove any obstacles that might hinder the exhaust flow, as mentioned earlier.

Best regards, Alex.

Okay, I don't plan to build something like that, but eventually, you'll probably have no choice, unless you want to pay endless amounts of taxes.

I installed a DPF in my Passat to avoid problems with taxes and driving bans.

I'm not sure if it's actually working, but according to the documents, it should be, and I have the green 4 emissions sticker.

"At least I've noticed that it reaches operating temperature quickly, even in normal city traffic, and also shortly after a cold start, and it's much warmer than the original catalytic converter (or the rest of the exhaust system)."
Here's how my exhaust system is set up: Turbo -> original catalytic converter -> DPF (Diesel Particulate Filter) including a catalytic converter upstream, all in the same housing -> pipe -> muffler.

Since I received the particulate filter from the environmental compensation program, it pays for itself within 3 years.

It probably depends a lot on how your vehicle has been modified.
However, I wouldn't recommend it, especially when it comes to tuning, because an unnecessarily high exhaust back pressure isn't really beneficial and also reduces efficiency.
Then it's better to include the purchase tax in the price.


I highly doubt that a DPF (Diesel Particulate Filter) will ever pay for itself.
The fuel consumption and the act of taking the dog for a walk to regenerate the DPF negate all the savings. The only thing you save is the penalty tax.

Steffarn wrote:

I highly doubt that a DPF (Diesel Particulate Filter) will ever pay for itself. The fuel consumption and the act of taking the dog for a walk to regenerate the DPF negate all the savings. The only thing you actually save is the penalty tax.

"For me, the DPF (Diesel Particulate Filter) is worthwhile. The reason is that when I had the engine conversion done, it was registered as Euro 2 (in the Golf 4, the engine actually meets D3 or Euro 3 standards). After speaking with a TÜV inspector and he reviewed my vehicle and all the documents, he reclassified the vehicle to D3 and PM2 after I installed the DPF."

1. I save some money on taxes.
2. I do not have to pay a penalty tax.
3. Do I now have the green sticker and am I allowed to enter the environmental zone without any restrictions?

And I haven't noticed any increase in fuel consumption, even with the same driving style.
"It only happens after driving in the city for a while, and then when I get on the highway and accelerate (while entering the highway), I see a white puff of smoke coming from the exhaust (as seen in the rearview mirror). After a few meters, it disappears. I would say it's the diesel particulate filter cleaning itself. It seems to be an open system."

What kind of performance have you achieved with the Golf ALH engine, if I may ask? And what kind of filter did you install?

I think it's around 140 horsepower and about 320 Nm (that's how it feels!), but I still need to get it officially tested.

The DPF is from Twin-Tec and is installed as an additional filter behind the original catalytic converter.