hangman1176 said:
i know this for 4s snowmobiles that dealers say do not run synthetic right off the bat, it prevents the rings from seating. Once synthetic is used oil consumption mayu occur at a minimal rate.
I have used synthetic oil in every new car I've had since the 80's, more than a dozen of them, and a host of used cars with every range of miles, low to high. NONE of them have ever used oil, or extremely little use on some of the hi-milers, except an old Mercedes 190e, and it leaked like a sieve. Some that used oil quit or slowed consumption after putting synthetic in. I have never owned a vehicle long enough to wear the motor out that ran synthetic. But I have seen and heard of many that have, and a properly cared for motor will last twice as long as one that's not. It's not generally the crank and bores that go, it's the other functions that give up and it self destructs.
Years ago I ran dino oil with Marvel Mystery oil, and that was almost as good as a synthetic. When we raced 2-strokes synthetics were the only way to go. Motors ran cooler and lasted twice as long, and the oil doesn't burn so you could run a much leaner ratio. Carbon just ruins a power valve on a race bike. Early on we used castor based oils, and they were really dirty. They still use bean oil in racing 2-stroke karts, but they don't run power valves in them, they are for making low-end power and karts run at over 10grand. They also rebuild them (rings) every 25-30 hours.
Plugs can only be read after a normal load run of some duration. They should be light brown, not white, not black. A four stroke does not have oil in the fuel so they don't get black unless something is wrong. The oil should stay in the crankcase and below the rings. That's what an oil ring is for. Carbon will gather on the top of the piston, in the ring grooves, and on the dome of the head, and can interfere with exhaust valves and injectors. A super-detergent topping oil in the fuel will reduce those deposits, as will an anti-carbon additive. Ring-free is the latter, but i prefer the former, PI falls under the former. If your fuel is fresh it should take MANY many miles and hours of use to build up carbon to where its an issue.
Motors are setup tight, and there's nothing wrong with a little cross hatch in a bore, if it's put together tight it will stay that way. Motors in general are setup with half the tolerences of years gone by. Synthetics have been demonstrated over and over to reduce friction and wear by a huge margin, particularly in high-stress wear areas, like wrist pins and valve guides.
Yamalube is a semi-synthetic premium oil with a good anti-corrosion package. Switching to a full synthetic after the first oil change is a non-issue. While manufacturers specify lubricants for their machines, consider that they are not in the oil business, they buy it from somebody else. There's nothing to say that there aren't competing products. So many people get caught up in this 'which oil is better' quandry, where any premium oil that meets those specs will be sufficient. There has never been a question in my mind that Amsoil, or Mobile, or Red LIne, or any host of manufacturers make a competing product. Just make sure they specify for your application.
Sorry for rambling...
