Sooting behavior in winter

Hello,

Okay, a simple question:

Does the soot emission of a TDI engine change with decreasing outside temperature, and does it produce more soot in colder conditions?
The context of the question is that my car (specifically, a "1Z" model) has recently been producing excessive black smoke. This was not the case when I bought it six months ago and after approximately 12,000 kilometers.
It's noticeable that the soot is almost only visible at higher RPMs, starting around 2500 RPM. This becomes particularly apparent when overtaking on country roads in third gear, accelerating from 70 to 100 km/h. In that case, the car being overtaken is practically enveloped in a cloud of smoke. However, there's nothing visible at lower RPM ranges. Previously, with other TDI engines, I was used to seeing a brief puff of soot when giving full throttle at lower RPMs.
Thank you.

No, quite the opposite!
In winter, the temperature of the intake air is usually lower, which results in a higher density and therefore more oxygen available for combustion.
I suspect you have a leaking charge air hose.
Normally, intercooler hoses are dry on the outside; if they're oily, you've found the leak at the point where the oil is escaping. Sometimes, you might also hear a whistling sound.

Your problem shouldn't be related to the outside temperature. It sounds like there's a lack of boost pressure. Check the entire intake system for leaks. If you have an aftermarket intercooler or similar device installed, an incorrect setting could also be the cause. The best thing to do is log the actual and target boost pressures. That will give you a clearer picture.

Sure, here is the translation of the text from German to English:

'edit: wolfi_b was faster'