Review on Synthetic engine oil ZIC X7 DIESEL 5W-30, 4 l by Mateusz Komorowski ᠌

Bought for Lacetti 1.4. I almost always change the oil, as indicated in the manual, after 7500 km, under severe operating conditions (winter, city, dust, etc.). This time I lingered a little and changed it to about 8500, while the internal combustion engine was already working noticeably louder. The mining was blackish, under the lid there was a yellow coating. I think, during my operation, this oil needs to be changed at a maximum of 6000 km. I flooded Zic 0w30 X7 for the winter, I’ll see how it will be in frosts, but judging by the tests, it doesn’t smell like zero, but 5w is flooded. Before that, I filled in GM 5w30, then I tried Total 0w30 for the winter. So far, Total felt better, but it's also more expensive. I keep searching.