Rotella T6 -> 5w40 vs 15w40?

[Cormanus]

I have a mate who would say, “it’s a Honda. If the stuff is brown and comes out of a bottle marked ‘oil’, it’ll be fine.” Me? I’d at least ensure the oil is certified to the standard Honda specifies for the bike.

[redbirds_imp]

I used Rotella T6 5W40 with no known side-effects or extra noise - in fact, the lump was quieter and gear shifting remarkably smoother compared to GN-4. Sub-zero winter riding also benefited being 5W and synthetic.

I would have never considered 15W40 for the CB1100, especially for cooler riding weather.

Same for me. I have used the T6 5W-40 for all my bikes for years. When new my 2013 CB1100 was reluctant to shift at times and excessively noisy, especially on hot days. First oil change I used the Honda synthetic 10W-30 and thought the problem would disappear as it broke in but problem continued. Next change was a switch to the T6 5W-40 and noise level was better and shifting stiffness disappeared. Best of all, T6 is a fraction of the cost of "motorcycle" oils. I do like the Honda oil filters as they are shown in tests to be better than most.

[Yata-Garasu_imp]

I used Rotella T6 5W40 with no known side-effects or extra noise - in fact, the lump was quieter and gear shifting remarkably smoother compared to GN-4. Sub-zero winter riding also benefited being 5W and synthetic.

I would have never considered 15W40 for the CB1100, especially for cooler riding weather.

Same for me. I have used the T6 5W-40 for all my bikes for years. When new my 2013 CB1100 was reluctant to shift at times and excessively noisy, especially on hot days. First oil change I used the Honda synthetic 10W-30 and thought the problem would disappear as it broke in but problem continued. Next change was a switch to the T6 5W-40 and noise level was better and shifting stiffness disappeared. Best of all, T6 is a fraction of the cost of "motorcycle" oils. I do like the Honda oil filters as they are shown in tests to be better than most.

Same for me. I have used the T6 5W-40 for all my bikes for years. When new my 2013 CB1100 was reluctant to shift at times and excessively noisy, especially on hot days. First oil change I used the Honda synthetic 10W-30 and thought the problem would disappear as it broke in but problem continued. Next change was a switch to the T6 5W-40 and noise level was better and shifting stiffness disappeared. Best of all, T6 is a fraction of the cost of "motorcycle" oils. I do like the Honda oil filters as they are shown in tests to be better than most.
Has anyone here done a used oil analysis of the 5w40 after it's been in theIr CB1100 for a regular OCI? (4000 miles)

Over on the BITOG oil forum, several people complained that the 5w40 was shearing down very quickly in their shared sump bikes.

Since air cooled bikes are known to be hard on oil and I live in an area with hot summers, that's why I opted for the 15w40 instead of the 5w40.

I still think the Rotella 15w40 was at least as good as the Honda GN4 10w40. The GN4 literally looked like burnt coffee after 3500 miles. At least the 15w40 still looked like motor oil...

Again, so far I'm very happy with the T5 10w30. No shifting problems at all, and the dreaded "missing 2nd on occasion" hasnt happened once yet.

FWIW, I have been using the [url=https://www.amazon.com/Fram-PH6017A-Ph6017A-Outboard-Filter/dp/B000276B2C]Fram PH6017a.

Silicon drain back valve, improved flow compared to car filters, decent reviews, only $6 at Walmart, and it's BLACK like my bike!

[GoldOxide_imp]

If I lived and rode in Texas during the warm seasons, I would consider 15W40 and experience and understand its performance on the bike. 5W40 is useful during winter and summer riding in southern Ontario.

Air cooled V-twin riders often use 15W40 even in the northern regions of North America.

Many Moto Guzzi riders use 10W60, as per the manufacturer's recommendation.

[peterbaron]

^^makes sense^^ +1

[Yata-Garasu_imp]

If I lived and rode in Texas during the warm seasons, I would consider 15W40 and experience and understand its performance on the bike. 5W40 is useful during winter and summer riding in southern Ontario.

Air cooled V-twin riders often use 15W40 even in the northern regions of North America.

Many Moto Guzzi riders use 10W60, as per the manufacturer's recommendation.

I use 15w40 in my two Honda VT750s, the Rotella T4 dino flavor. It's the perfect oil for those bikes, but those are liquid cooled V twins.

In my experience, 15w40 was not a good match for the air cooled CB1100, even for Texas summers

Lots of extra valve ticking coming from the top of the engine, all last summer.

I went with the T6 15w40 in the CB1100 because I thought the synthetic version might be more forgiving during the cooler winter riding months and in fact it was fine, comparable to the Honda GN4 10w40 that I used the year before.

The valve noise faded somewhat once the T6 had some miles on it, but it was never as quiet as it is now with the 10w30.

I should probably start a separate thread about my experience with T5 10w30 in my CB1100. It's not MA2 rated, but so far it's doing a great job. Better, in fact, than the two other MA2 spec'd oils that were in it before, including a Honda branded oil.

There's too much fear and insecurity about MA certification. It's early days yet, but I'm willing to bet that the T5 is going to be an excellent oil for the CB1100.

I fact, I did bet... That's why I decided to fill my CB1100 with T5 despite the lack of MA letters on the bottle.

I would venture that the 5w40 is probably a serviceable oil for the CB1100 as well, but it might shear quicker than other oils with fewer Viscosity Index Modifiers.

The main thing I'm trying to say here is that, despite the hot Texas summers, the 15w40 wasnt a good fit for my CB1100.

I hope this info is helpful for someone considering Rotella for their CB1100.

[Frenchie]

Just posted this in another oil thread:

For the Rotella T6 fans, it is now available in 10W-30. Interestingly, someone who commented in the link below is a CB1100 owner:
https://bobistheoilguy.com/forums/thread...30.374593/

[Whoops]

I used Rotella T6 5W40 with no known side-effects or extra noise - in fact, the lump was quieter and gear shifting remarkably smoother compared to GN-4. Sub-zero winter riding also benefited being 5W and synthetic.

I would have never considered 15W40 for the CB1100, especially for cooler riding weather.

Same experience here.

[Ollie]

I'd been using T6 5w-40 for a few years as that weight was what BMW spec'd for the R1200 water cooled bikes. It worked fine in my other bikes that I used it in and the mowers, other than my air cooled mowers tended to consume a bit more than they did when I used M1 15w-50. When Shell brought T6 out in 15w-40 I started using it because 15W is plenty low for start up here and it would have much less viscosity improvers than the 8X any 5w needs in order to flow as a 40W.
The result has been the bikes don't care and the air cooled mowers seem to like it more, and they're back to not using any measurable amount. The CB1100 runs and shifts as smoothly as ever, probably better than with Honda 10w-30 and T6 5w-40 *after the oil has been for a couple thousand miles*.