Cheap prices. In principle, it is caused by poor-quality products. Specifically wolf oil. I serviced two cars. Some time later, after opening the valve cover, oil sludge was found, and the employees themselves said that this was due to poor-quality oil. When I replied that I was servicing cars here, we fell into a stupor. Then their director of quality contacted them, said that they allegedly added another oil (this is not true!) and because of this a sludge was formed. I couldn't top up the oil of another brand, because there was always a residue from the canister that was always in the trunk, which actually made no sense to spend money again. Further, this director, after consulting with GT Oil experts, said that their WOLF oil did not protect my engine from a short-term demise and thanks to their oil, my engine still lived. I did not argue, stupidly there is no desire to waste time and nerves. One thing I can say is that most of the products are not unknown cheap brands, so think a few times, it's better to overpay for an oil change than to overpay for an engine replacement.
The oil was replaced carefully, politely and, most importantly, competently, I am glad that this field of service work and services began to develop in Kazakhstan, up to international standards. I recommend everything