Oil weight for Rocket III

Hi all, I just bought a 2005 Rocket III. in the manual it says to use 10W-40 or 15W-50. What are most folks using? Here in Texas it is pretty hot so I might go with the 15W-50 in the summer and the 10W-40 in the winter. Also, with 15W-50 you're pretty limited (Mobil 1 Racing 4T Triumph-branded and BMW, but what brand are folks using if you use 10W-40? Thanks

On my SPrint ST I used the Mobil 1 15W-50 in the winter, and Royal Purple 20W-50 in the summer.

[Toystoretom]

Where is Ron when ya need him???

I use the Triumph oil myself but a lot of people use Amsoil , but I don't know the specific part number for that. I think they have a blend for bikes with wet clutches.

I wouldn't be afraid to use 10w-40 all year round. Syn oil is very tough and doesn't break down like the Dino oil. Ford is running 5w-20 in many of their cars and trucks... even in Texas... all year round. And its Dino oil. Triumph probably put the two chioces in there just in case you are in Lizard Flats Kansas and they only have one certain weight to choose from :-D

Tomo

[Kilibreaux]

I run 15W-50 Mobil 1 fully synthetic. Got it at a local autoparts store for $4.89/qt.
Riding temperatures here range from around 50F-110F.
I've got about 3200 miles on my last oil change and it still looks as if it were freshly poured.

[cockneyusa]

Although I haven't changed the oil in my Rocket yet (450 miles) I have used Mobil1 15-50 in all our bikes. I read an article that asked various people from the oil industry what oil they used. 8 out of 10 used the 15-50 Mobil1. They aslo didn't change the oil when "recommended" as synthetic oil lasts much, much longer than mineral oils. They used the normal automotive oil not "special" motorcycle oil. As long as it does not have friction inhibitors (for the clutch) in it it will be OK.

Our bikes run quieter, and we've been using it for three years now with out any problems. The bikes are a Yamaha Warrior 1700cc and a Kawasaki 1500cc Drifter.

Yes I intend to use it in the Rocket at the first oil change.

[Ugarte]

I use 10/40 amsoil year round and change every 10k miles.

[Diego]

Why would you even ask about weight?

No...seriously. What were you thinking? That after less than two years' service on this machine, any of us would suddenly be smarter than the factory about what weight of oil to run in it???

C'mon, give us a break. Last thing this world needs is another looney oil thread. :razz:

Like our moderator says, I wouldn't be afraid to run 10W-40 synth in it all year, either. This is a big, lazy, understressed engine.

It's also water cooled--meaning, unless you lose your coolant (in which case you've got other problems to fret about) your OIL is going to be running within a few degrees of the same temperature, summer or winter! That's why most of us end up with the sort of results Kilibreaux reports.

From a protection standpoint, that's why it doesn't matter whether the "high" side of the weight number is 40 or 50. If anything, the thicker viscosity just represents additional power loss and waste heat production.

The low-temp number will be relevant to cold starting, of course; but I can't see any reason to ever go over the 15W recommendation.

> Triumph probably put the two chioces in there just in case you are in Lizard Flats Kansas and they only have one certain weight to choose from

That must be it. Especially since, in some parts of Kansas, we have to ride over to the next county to even see Lizard Flats on the distant horizon.
:-D

[Robyyy]

Check your blood pressure..