Not relevant for full synthetic oil as I learned tonight, thank you for mentioning it
No emotion from this camp, as I don't care what oil folks use.I think we could come up with two other kinds of people. Everyone with the same opinion as mine, and everyone else who is wrong.
Maybe we could get the emotion level down some?
Chris
I know, facts don’t always sit comfortably.So says the people who sell and market it
Shell also claims their stuff is JASO certified.
If you want to use it, use it. Your bike, your choice.
If you don't like it, try something else.
Probably because there's been numerous cases of manufacturers changing oil ratings due to engine issues, largely because they wanted to meet CAFE standards and were using oil that was too thin in order to get under said standards.
0/20 met all the standards for recalled gm 6.2 engines till it didn't .
Your argument about auto manufacturers using lighter oils for MPG reasons rather than engine longevity contradicts the idea of using something like 5w-40 Rotella, as the 5w part of the rating falls under the manufacturers minimum recommended viscosity range.
My point is purely that just because an engineer that works at the OEM said it, doesn't mean it's actually true. Engineers make mistakes, and companies have different priorities than end users.
The CAFE requirement I referenced is a fuel mileage requirement, not emissions. I did not reference emissions standards. Being an engineer by profession, and understanding some of the standards and validations a manufacturer has to comply with leads me to perhaps a higher level of respect for those engineer’s decisions than those outside the profession perhaps.
The only question I would ask is why are you considering the switch? Some ask why not run the recommended 10-40 and I understand that T6 only comes in 5 or 15 weight and many people want to run Rotella as it is a proven, low-cost and safe performer. So I would think most people are unsure whether to go thinner or thicker than the 10 weight recommendation. If that is your only reason for the question, than I would say 15 weight. The 5 weight should only be an option if it were really cold. As @Al st1100 pointed out, GM is in a big pickle from running to thin an oil in some of their engines...I'm considering switching from Rotella 15W-40 to 5W-40. Would this be a wise choice? Any input or recommendations would be appreciated.
I am certain that fuel efficiency is a consideration in the choice but to claim that it comes at a significant expense to longevity I find highly questionable. Modern automobile engines are more mechanically reliable and longer lasting than they have ever been and that is with these oils. Yes there are exceptions to that and there will always be examples of premature engine failures for many different reasons including because of a screw-up in the choice of oil. The exceptions don't define the average however. I don't know specifically about motorcycle engines but I can't see it being hugely different in this regard from automobile engines.
I don't think that there can be any rational claim that engine oils have not improved. Any modern 5W oil is of a much higher quality than any 10W oil that was available when the ST1300 was designed. By the same token the same is true of any modern 10W oil as well. The quality of the oil is no longer the determining factor. Your statement assumes that a modern 5W oil is far superior to the lesser quality 10W oils that were available when the ST1300 was designed and it therefore must be an improvement. I have no idea because I am clueless as to whether the trade-off in viscosity is worthy of consideration or not. This is a question that I do not feel needs answering. The 10W and 15W oils available today are of the same high quality as the 5W oils. Since there are high quality oils available that do comply with the viscosity ratings that the manufacturer has specified I just follow the recommendation.
Emission standards but not CAFE mpg standards which I took to be your point.
