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.

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?

What type of oil is suitable for a 1.4 naturally aspirated manual engine? Is 5W-30 okay?

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. 😬