Two car questions, for a newbie

[Mr Downtown]

Changing oil--harder than paying someone who knows how to do it the $15. Basically you have to pull a plug at the bottom, let the oil drain into a container, plug the bottom, and put oil in the top.

Gas prices are tracked on several sites, but no one can predict trends (that's what futures contracts are for). Also, keep things in perspective. For a small car, a ten-cent difference per gallon translates to a whopping dollar per fill-up.