First, hello all. This is my first post here having just discovered the board last week. I've been looking through it for information in regards to what oil may be best for me to use in my '03 Buick Century that I just bought last week. The Buick has 10K mi on it and still has 2 years factory warranty left. The engine is GM's 3.1L V6. After getting it home I changed out the oil to Havoline 5w30 with a Purolator filter - I was tempted to use Valvoline but steered clear of it after seeing some of the opinions of it on this board. Previously in the Grand Am I traded in (same engine type as the Buick) I ran Valvoline 5w30 from new to 20K miles and then switched over to Mobil 1 using Purolator filters (and PurOne's when they were on sale). The Valvoline saw 3K mi changes and the Mobil 1 was changed at 4K mi or every 4 months. I'm not adverse to using the Mobil 1 in the Buick except for cost. I'm also curious as to opinions on the Oil Life Monitor. Would it be wise to go by it or just go by the good old "3K mi" method? Alternatively I'm also considering using Havoline Synthetic 5w30 (assuming I can find some place around here that sells it - no luck so far) and just changing it when the oil monitor tells me its time. And yes I'm aware that Havoline sythn is mostly just a group III oil with possibly some PAO/Esters. Mobil 1 is $3.54/qt around here (and I can get it for $3.30 with my discount through my employer). Alternatively I've seen the Havoline synth going for about $2.60 the one time I did see it last year and an auto parts store. So any suggestions - and sorry for the lenght and rambling on.