So a couple weeks ago I was on a 1900 km trip from Latvia to southern Germany. On the second day I was still in Poland when my tank was running low. I stopped at a Shell station and looked at the pumps. I know that I needed diesel fuel and there was a choice - a black pump with Diesel followed by red pump with Shell VX Power Diesel and then a bunch of green pumps with gas. So I too the red pump and fuled up. The engine ran great, I was soon in Germany and going down autobahn with very nice speed. After a few hours the gas tank was rnning low again and again a Shell station was the first I found. I stopped there and saw the exact same pumps as in Poland - a black Diesel followed by red Shell VX Power Racing and a bunch of green pumps. I picked up the red pump again, filled my tank and drove on. After some distance I noticed that I was getting some interruptions of power and maybe slower acceleration, but it was not severe enough to make me to stop. So I drove on. All 300 kilometers to home. While sometimes speeding up to 180km/h. Only when I got to home and slowed down to city speeds did I notice that the power interruptions were more serious and also that the check engine light was on. So on Monday morning I got up early, got in the car, started it (without any problems) and drove to the nearby Mercedes dealership.
Only then with the help of the technitian I realised that Shell VX Power Racing is not the same as Shell VX Power Diesel despide being in the pumps of the same color and location. The car had to stay in the service overnight. They removed all the injectors from the engine, cleaned and inspected it fully. The only part that actually needed replacing was the fuel filter. Just to be sure after reassembling the engine they also ran it for 75 km on the test stand at all kinds of speeds and power curves. And they refuled it back to full and also washed the car before returning it to me. Shuttle service from the service to my workplace and back was also included.
In the end this mistake cost me 635.50 EUR, but it could have also been many times more than that. Apparently the VX Power Racing fuel also contains a bit of lubricants, just like many diesel fuels, so that might have saved me. Or the good quality engineering that goes into the Mercedes engines. Or both. Still, this is one of those life lessons that you do not forget that easily.