Void warranty, and "not worry about it?" I'm worried. :surprise:Put it this way I woulds put 10w40 synthetic in mine and not worry about it, it stays in grade longer at high temperature, Honda don't thinks its needed and they are probably right but I don't think it will do any harm other than perhaps void your warranty if Honda were being very picky.
They are both 10W so should be the same in the cold.I was told by the Honda importers here that I should use 10/40 and not even full synthetic. 10/30 is not available here.
If the JASO spec of the oil is within that specified by Honda then one should not have much to worry about, unless one is operating in extremely cold temperatures during winter time.
If you're going to try it, better to perform used oil analysis during your intended oil change interval, and make sure it's working like you expect. Barring that, you could see how that oil holds up in similar motorcycle engines in the motorcycle used oil analysis forum on bobistheoilguy (I'd post a link to that forum, but my post count is low, and I'm not allowed to).Hondas recommended interval is 8000 miles and you can double that with Amsoil up to 15,000 miles
Thanks!Only 10W-30 in Shop Manual.
GN-4 10W-30 or better. As my local dealer and people whom I know having years more experience have said. Use the brands oil and filters, keep the receipts, go by the recommendations in the manual for changes and they have no reason to deny any warranty claim.the Owner's manual tells us to use 10W-30 oil, what would happen if one used 10-40? will this do any harm and why?
If you're concerned about voiding your warranty (I doubt you would be, but I don't know), call Honda customer service and get the definitive answer. Shouldn't take long to settle the matter and put your mind at ease.I was considering it until you said "... perhaps void your warranty..." My consideration was dependent on knowing more information. Now that I have that warranty info, I am no longer considering 10W-40. Does that make sense to you now?
MCGMB,If you're concerned about voiding your warranty (I doubt you would be, but I don't know), call Honda customer service and get the definitive answer. Shouldn't take long to settle the matter and put your mind at ease.
The times I've called various motorcycle manufacturers CS hasn't been that bad.MCGMB,
Do me a big favor, (please) call Honda customer service, stay on hold for 19 hours, ask the question and then get back to all of us with the answer.