It seems to me that a thorough look through the UOAs posted on this site reveals not one whit of an advantage to using synthetics over a good dino in most cases. I would use a synthetic only if one of the following is true:
- You intend to extend drain intervals beyond 7500 miles.
- The engine has known issues with overheating of the oil, for example an air cooled motorcycle engine.
- The engine has known oiling system weaknesses or sludging problems.
- You expect to encounter extremely broad temperature ranges on a single fill.
- The manufacturer of the vehicle recommends synthetic.
Even in most of the above conditions a good argument could be made for dino, based on results posted on this site. Most modern engines are good, healthy designs and will not be subject to any of the above.
Plenty of people here have run engines several hundred thousand miles on dino without even the benefit of A-RX cleanings.
This is coming from a former confirmed advocate of synth, and I attempt to maintain my vehicles for maximum lifespan. In my humble opinion, most people are better off using dino with 5k-or-so OCIs and putting the savings into other aspects of preventive maintenance, possibly including occasional Auto-RX treatments, and more importantly making sure the car's body, interior and subsystems last as long as the engine will.
My humble opinion.
- Glenn
