Blackhawk helicopters live on synthetic
I've been hooked on synthetics for over twelve years. One day I visited the local Air National Guard airbase. the mechanic took me for a guided tour of his pride and joy, a Blackhawk helicopter. He informed that each turbine (there are two) costs $750,000 and that they NEVER change the synthetic oil! In addition there is a metal indicator for the helicopter's transmission that indicates the amount of metal particles in the tranny. If it ever exceeds a certain level, the pilot MUST bring the aircraft down immediately because the excessive amount of metal can destroy the transmission.
That being said, if the Air National Guard NEVER changes the synthetic oil in their Blackhawk helicopters which cost as much as a Mercedes Benz dealership, I think it fairly easy to acquire extended drain intervals on today's high quality synthetic oils. the key to long drain intervals is FILTRATION FILTRATION FILTRATION. The best filters in my opinion are sold by Amsoil. From the new patented Donelly filters to their famous dual remote bypass oil filtration system, Amsoil leads the pack when it comes to keeping your oil clean. The bypass filtration system they sell filters to one tenth of one micron, which is downright small.
I have a merc 300DT 1984 which uses Amsoil from stem to stern.
15W40 Marine Diesel Oil (an old favorite for diesel owners)
Amsoil ATF Synthetic Transmission Fluid (runs the tranny about 15 to 30 degrees cooler than petroleum based tranny fluid)
Amsoil series 2000 Racing Lube in the wheel bearings
Amsoil 750,000 mile over the road diesel use rated (yes, you read that correctly) coolant
Amsoil Series 2000 75W80 Gear Lube in the differential.
This car will most likely outlast me and my grandchildren
The other car is a pristine 1991 Merc 560SEL as follows:
Amsoil European formula 10W40 synthetic motor oil
Amsoil ATF Synthetic Transmission Oil
Amsoil 250,000 mile rated coolant (same coolant different ratings for diesel verses gas)
haven't installed the wheel bearing grease or the gear lube yet
at the next oil change I will switch to Amsoil Series 2000 0W30 racing oil. have read some tests on this oil and it is the ULTIMATE in lubrication. Not cheap, but neither is an engine in a merc 560SEL.
I do use Redline Diesel additive and it seems to work well with the new lower sulphur diesel fuel the EPA has dropped in our lap (15 PPM verses the previous 300 PPM). Amsoil just came out with a combination diesel additive that I will probably switch over to.
BG makes a great injector cleaner, I would consider using that in lieu of the Amsoil injector cleaner.
here's a link for those techies who want to know how Amsoil rated in independent testing against the major oil manufacturers:
Synthetic engine / motor oil comparison - Amsoil beats Royal Purple, Mobil 1, Castrol, Hi-Tec, BP, Torco and Shell on the dynometer.