What does it mean when the idle is a bit rough? Do you all use 5W-30 oil?

Yesterday, I went for maintenance, and they usually use 5W-30 oil. But this time, the technician used 5W-40 oil. I'm not sure if this will have any impact.

What engine oil do you all use for diesel versions?

For the 2016 Roewe 1.5 automatic, do you use mineral oil or 5W-20 or 5W-30?

What does it mean when the idle is a bit rough? Do you all use 5W-30 oil?

Is the engine oil for the 2013 Alto 5W-30 or 0W-20?

What type of engine oil do you all use?

I've been driving a 2009 Kia Sportage manual GLS with 120,000 km on it. I've always used 5W-30 engine oil, but recently it seems to be burning oil a bit. Should I switch to 5W-40 oil for maintenance? Has anyone experienced this before and can share some insights?

What oil do you all use for maintenance?

Is the Mobil 5W-40 oil I used today not as good as 5W-30?

Can I use 5W-20 oil for an old Mazda with a 623 displacement that has run 300,000 kilometers? The 30 oil feels a bit thick. 😬