The key to your full Synthetics and to make sure your NOT wasting money is to go the distance and be certain you are using a synthetic that uses only Pure Ester base stocks. Your other base stocks the type II and III cracked hydrocarbons and what not found in Mobil and Castrol are barely able to be called synthetics.
There are but only a few 100% Ester base oil formulas available and the Silkolene Pro4 ain't one of them that I can tell . These full ester oils are race only and some are hard on the soft white metals , seals and more . Some of the non race engine formulas using primarily Esters with some Pao are borderline tough on said metals . Bench corrosion tests have been set for just such .
Esters have to incorporate some PAO into the formula to offset seal swell just as PAO synthetics need some Ester to offset seal shrinkage . Ester does other groovy things but too much a topic to go into here .
All the Mobil car synthetics uses true PAO's with AN correction fluids . Pao's are group 4 and the Exxon/Mobil's AN's are classified in the group 5 category right along with other Esters such as PE , D-Basic , the newer Complex Esters and others .
The Mobil Truck and SUV 5w-40 and both of their bike oils are PAO with around 30% Ester and do not use the AN fluids .
Yes Castrol automotove uses primarly Group III but they also uses a group III called Slax Wax in some of their oils . With these two base oils they still blend a certain amount of Pao and Ester both to obtain the viscosity target and to maintain seal swell in all their oils but to varying degree's as stated . Same deal with their bike oils as far as I've been able to determine .
Hope this helps .
Aussie Busa
Your correct . It's very wise to use a true synthetic in a M/C turbo motor . The bearings get very hot and can coke mere mortal oils . HT/HS comes into play as well . In the automotive world for example a 10w-30 dino's cutoff point for many manufactures is 86F . Using Mobils 10w-30 Synthetic as example one can use that oil in place of any 40wt above that temp when a maker calls for such . That there speaks volumes IMO since it's just a 10 centistroke oil whereas Castrol GTX dino 10w-40 was a 14.5 centistroke oil last I saw .
Oil is not oil anylonger with the new API SM oils that are only backward compatible to SL whereas API SL as marginal as it was IMO was backwards compatible to SG in which had abundent phos and zinc even though in those days mineral basestocks were not near the quality of todays group II and II+ .The NOACK is much better with the group II's and often approach the group III's depending on the viscosty . SL oils had the phos capped at around 900 parts per million while the new SM is at around 660 PPM vs no cap and depending on the formula SG had from 1400-1800 PPM of zinc which is the primary anti-wear additive in any oil .
I'm not sure I will ever be able to understand the Busa owner who still chooses to use dino's when they can go up to one full year on some of today's synthetics even if they just drain at 6 months while using the same filter . Thats just pizza money there but to each his own I guess since many really don't undertand the newer base oils with their vastly superior film strength , affinity to attach to metals and the newer additive technology along with the very high and long lasting TBN some of the oils have so again... to each his own .
4 quarts @ 3 bucks per quart 3 times a year or 4 quarts at 5 bucks each once per year . Engine oil analysis has quantified the results of doing the latter for me , my bikes and how they are used . The cars here that I own as well .
We all beat to different drums though so do as you like . Just my 2 cents based on what I know .
