mineral oil will never be "better" for an engine than a synthetic. Synthetics are basically clean man made lubricants not a couple million year old rotten plants. It's about the viscosity of the oil, not about mineral vs synthetic. Only use mineral for running in. It also depends on the condition of your engine. The 4AGE is not an "old" motor either.
Mobil 1 is good but only for engines that don't burn oil and are basically newly run in(never use a good synthetic oil to run an engine in. It lubricates the parts too well and they don't wear which is the whole point of running it in)... read this for more info:
Sun, 07 July 2002 13:22
