Yes indeed Lancer is a gem of a car, we have one since 2006, 1.3 GLX M/T, bought brand new back then, and Alhamdulillah it has been a very loyal car.
Coming towards your question, since day 1 I am using 5w30-40, initially it was Shell for some time but then I permanently shifted to Caltex Havoline, car performs flawlessly Masha Allah, mine is driven around 78,000 km so far.