quote:Originally posted by Husker:
Synthetics were developed for jet aircraft turbine engines. In the early
days of turbine engines, the motor oil would break down and leave deposits
and cause engine damage, which would crash the plane. Synthetics allowed
higher operating temperatures with almost no breakdown (visualize the
synthetic oil commercial where they fry conventional oil in a pan and then
scrape the deposits with a spatula). However, in jet engines, the oil does
not seal the combustion chamber like in a car engine.
90% of what you read about Synthetics is sourced from the companies selling synthetics. There are some drawbacks to synthetics. True they were developed for aircraft and in fact I run it in my turbine aircraft. They were put into use in piston aircraft (pure synthetics) and soon found engines and props could not make it to TBO. Variable pitch props as well as engines were slugging up and failing early. There were a couple big lawsuits and the oil companies lost. There is no limitation against pure synthetics in the “Piston” airplane industry but everything marked now is a blend.
The problem is the airplanes still use leaded fuel and the synthetics could not break down the lead; it turned to sludge. Since we don’t have lead in car fuel anymore it’s not as big an issue but I see it as no more better oil then the additives. My brother running his cobra on a track changed to synthetic and lost the bearings before the end of the event. Swapped the bearings, returned to dino oil and put another 20K hard miles on the engine. He attributed the bearing loss to the low adhesion of synthetics and the lack of racing type additives which protect the bearings in hard cornering and temporary oil loss. There have also been reports of much more rust in the top half of engines; especially during storage where the synthetic simply does not adhere to the steel as well. Maybe it’s “too slippery”. Either way I find 90% or more of the info related to synthetics generated by the companies directly, indirectly, or regurgitated.
The biggest problems with wide viscosity oils is that it takes a lot of additives to do this….which means less oil. Wide band oils are known to have less oil content and do not work as well overall.
Lastly, different oils have different detergents and additives. The best thing you can do is chose an oil (synthetic or not) and stick with it. Changing your oil means you may be changing the chemistry enough to break up particles which were otherwise set. One oil creates one type of deposits while another oil can break those up and send them through your system.
Gary