For a 2010 Suzuki SX4 with a 1.6 manual transmission, what spark plugs and engine oil do fellow car enthusiasts recommend?

20/30 is acceptable.

Change to 0W-20 engine oil.

The used car seller said that older cars should use 40 viscosity oil to protect against mechanical wear. I'm not sure if that's true, but next time I want to try using 30.

I replaced it with a Bosch one at the repair shop.