Once again I am going to cover engine oil, as there has been a lot of discussion concerning it lately.I use Chevron 10-30 in all my vehicles. It is what most of the oil change specials in this area provide. No I don’t change my own oil just too much of a hassle at my age and really not worth it for what they charge. If I go synthetic I may change it then. I have a Bonneville with a 3.8 that had a Good Wrench engine installed recently. I may use synthetic in that. My problem with synthetics is that I just cannot leave it for the recommended interval so it does get expensive. If I do go to a synthetic it would probably be Mobil 1. I do not think the semi synthetic are worth the $ as the percentage of synthetic is very low. My Dakota and Pontiac convertible have a lot of miles and every now and then I use a high mileage, but I always assure the oil is changed hot at the next oil change, to be certain all the extra additives are removed. All the name brand oils are good in fact they are not that different except for a few of the more expensive ones. For example Gibbs racing sells a oil that is high in zinc and this is a good choice for older engines (before Lead free). There are several other specialty oils on the market. I guess I if would have to choose the best oil out there it would be Castrol. The problem is it is hard to find a shop that uses it (to expensive). I used Havoline for many years then when it became hard to find I went to Amoco then Chevron bought Amoco so I went to Chevron and as I said before many shops in this area use it. I have no complaints about the performance, it is a little stiff in the North Dakota winter but I have no where I have to be so I just wait for warmer weather. Bottom line is your car is one of your most expensive investments so use the best oil you can afford. If you can leave it alone synthetic is by far the best but if you are anal like me and cannot leave it in for the 6-9 thousand miles with one filter change then go with whatever name brand is available in your area. Stay away from the high mileage and semi they are a rip off, also avoid most additives here again they are a waste of money. I use 2 Seafoam and Lucas but only on a very rare occasion and then only if I am trying to cure a specific problem (noisy lifters is one). I also use Seafoam as a stabilizer and have excellent results from it. To most technicians oil types are like blond, brunettes and red heads it is matter of preference. A good site for oil references is chris-longhurst.com he also has a tire speedo chart among other types of info, once you start reading it is hard to stop as it does contain a ton of info.