I run Mobile 1 EP with the Mobil filter (blazer filter) and do my oil changes twice a year (spring, fall) and it cost $60 for the year. Theirs no reason not to run synthetic oil as its benefits out way the costs of a damaged engine. Synthetics oil has a much better ability to absorb water than regular where they typically stay seperated. This can and will help to protect you from spinning a bearing if you develope an internal coolant leak or after doing a set of LIM gaskets and you don't get all the coolant out. Some peoples time is worth more than the money so synthetics do have they're purpose.
I'll take amsoil over RP any day of the week. I run Mobile 1 EP because its about half the price of amsoil when on sale.
