I have used synthetic oils since the early 90s in race cars. My 540hp Chev Sports Sedan engine built for synthetic with 1.8 to 2 thou down the crank had to have a softer presure relief spring as it had way too much oil pressure on start up. Adjusted to 55lb hot it did 2200 race km and the bearings were totally reuseable. Oil pressure was still the same. I would have reused the bearings but the crank was cracked
Not a fault of the oil. The solid roller cam and lifters were still perfect, heads were fine. Compared with 25/50 Pennzoil race mineral oil [ a good product] it ran 15-20 deg cooler on oil temp. Was run at 230 deg at the windless tunnel of the AGP track, no problems. Pistons too were fine. This engine normally saw 7200 but occasionally 7500 and was 12.5-1 on avgas.
I usually changed the oil every third meeting. Between 100-150km per meeting.
My classic speedway Supermod, again a proper race engine . A 202 Holden, 250hp again on Avgas seeing max 6800 has had no issues, engine has been in the car 25 years and oil changed maybe twice a season. Runs 45-50psi oil pressure though comes in off the track with the oil light [25psi] on. Did that from the last rebuild. Has done 50 or so shows. Solid lifter cam.
So all very good on synthetic. I use it in diffs and gearboxes as well. On the modified diff temp is way down as is the gearbox.
My current,, currently resting Falcon improved production car, was 351 Cleveland and did about 12 events, again no issues. Gearbox, single rail GT box is living happily as is the BW diff. Both a bit fragile for the exercise but no issues. And the single rail changes a LOT nicer with synthetic as well
I use it in my Ford Galaxie cruiser, in the Landcruiser and again no issues.
While many say it is not compatible with methanol Brad Scotcher Aust 1 in 93 in Super Sedans used it with no issue as did John Hughes in the Pantera Super Sedan. Change the oil about twice a season. I would have been more often. They convinced me to use it as well.