I just bought an '01 Corolla CE that's been running regular oil up to this point. I know synthetic is better after 10,000 on a new car but is it worth switching at this point. My guess is yes but I'd like to make sure before I double my oil change costs. Also ...what do you guys recommend changing at? The mechanics here say the newer cars can go up to 8000km/6mths on regular and a lot higher on synthetic. I've always changed my cars a 4-5,000km and
3mths regardless of what I use or what vehicle it is ...Thanks!