I was given 5 free servicing as an package for buying a new car. The appointed car workshop is motoricarz garage. At the first few servicing it was ok and no issue. But on my last visit I was surprised the mechanic took out a plastic container containing oil from unknown source and top up the oil into my engine. I didn't make a fuss as I thought it may be surplus oil from left over. After I collect my car and drove for about an hour. I noticed the car engine became noisy and loss of power during pickup. My fuel mileage was very bad. Usually, I can clocked 125km when the fuel guage dropped 1 bar as compared now at 75km. I was very annoyed as it never happened prior to servicing. Immediately, I drove to another workshop and replaced the engine oil. To my horror, i found the oil viscosity is of poor quality after it was drained off. I changed the oil to 0W-20 grade and everything is back to normal. Perhaps free servicing is cheap but no good.