What type of Engine Oil should I use - A Class 1.4 2002 Petrol

[RickStar007]

Hello everyone,

My Mercedes A140 Avantgarde, 2002, 1.4 Petrol Engine, Manual last had
Mobil 1 5W 40 Engine Oil Fully Synth....

Can I use Mobil 1 0W 40 Fully Synth in my car when I next do an oil change?

Which one is better / would you use?

Mercedes told me not to use the 0W 40 because that was really for AMG's, Smart Cars, ETC??? and would be too thin?

Thanks

Ricky