BDG Engine: Enough Power?

Hello everyone,

I've had an A6 Avant with a BDG engine for just under a month. It was first registered in July 2003 and has 76,000 km on the odometer. It has 215/55 R16 summer tires.

Now I'm increasingly unsure whether the engine actually has as much power as it should.
Perhaps everything is fine after all – I haven't had the chance to drive another A6 with a BDG engine yet... I also realize that this car (which is relatively well-equipped) isn't exactly lightweight, especially with me in it.

'In the lower RPM range, it feels a bit weak; my AFN felt like it pulled better there. However, starting around 2800-3000 RPM, you can really feel a noticeable increase in power (acceleration) – it pulls much stronger at that point. It then pushes quite powerfully. In gears 3 and above, this increase in power (difference) becomes less significant; you notice it less.'

The maximum speed, according to the speedometer, is reached at... 220 km/h, but it takes a while to get from 200 to 220 km/h. And: According to GPS, it's 'only' 207 km/h.

1. Question:
Sollte er nicht echte 220km/h (GPS) erreichen? Oder sind 220 lt. Is the speedometer working correctly?

My last A4 AFN, registered with a top speed of 192 km/h, easily reached 190 km/h according to the GPS – and with patience, even 200 km/h (GPS).

After reading through everything here and on other forums for days, I can imagine that replacing the mass airflow sensor (MAF) might improve things. However, I don't want to just buy a new one without good reason.
Unfortunately, I don't have a VAG-COM either to perform a diagnostic test drive.

2. Question:
What version of VAG-COM would I need (at minimum) to perform a diagnostic test drive? Is the shareware version sufficient? Is it available with a USB cable?
I have a relatively modern laptop with a USB port (no COM port). The version costing €249 is too expensive for me, even just to try it out.

3. Question:
Is anyone from the western part of Munich (Puchheim) or surrounding areas who has a VAG-COM and might be willing to do a diagnostic test run with me sometime?

Sure, no problem. Here's the translation:

'Thank you in advance.'

Best regards,
Martin.

If the conditions are right – a flat surface and no wind – it should be running at the speed indicated by the GPS; the speedometer is never accurate anyway. The shareware version is sufficient for measuring. Rainer can provide more information about the hardware.

A sudden jolt like that isn't a good sign, but without proper measurements, you're just guessing.

Thank you for the response.

Well, it's not exactly a jolt... I would describe it like this:

At 1000 rpm with full throttle, the power builds up evenly from approximately 1200 rpm to around 1500-1800 rpm, and remains at that level until about 2500 rpm. From 2500 to 2800 rpm, the power continues to build, and then stays at its maximum level all the way up to the rev limiter.

Okay, so that leaves the question:
What hardware version do I need? Does the kit work with a serial cable and a serial-to-USB adapter?

Hope: Is there anyone in the western part of Munich who would like to join me for the measurement run (see my first post)?

Happy holidays to you all!
Martin.

Hi again,

Will this kit work with my car? (A6 2.5 TDI 4B, BDG, manufactured in July 2004).

http://shop.dieselschrauber.de/product_info.php/cPath/21/products_id/38

Best regards,
Martin.