Rotella T6 -> 5w40 vs 15w40?

[Yata-Garasu_imp]

This question is aimed soley at people who have used Rotella in their CB1100s.

I have used T4 15w40 dino oil with great success in my Nighthawk 750 (inline 4) and Shadow 750 (VTwin).

Honda recommends 10w30 for both of those bikes, but the Vtwin definitely seems to prefer the T4 15w40 over the Honda 10w30, ie, smoother shifts and quieter engine. The Nighthawk doesn't seem to care either way.

The CB1100 is very similar to the Nighthawk. I'm currently using Honda 10w30 in the CB1100, but I'm thinking of going with the 15w40 T6 on my next oil change.

I was initially considering the T4 in the CB1100 too, but according to Shell, the T6 15w40 flows better at cold temps than the T4, and has better shear protection.

I like the idea of a full synthetic in an oil cooled bike.

Since I live in Texas and never ride when the temperature is below freezing, I think the 15w40 should be fine, but I'm curious about the 5w40 too... I'm wondering if there would be any benefit to the 5w40 besides just the increased flow at low temps.

From what I have seen, both the 5w40 and the 15w40 Rotella oils have a weight of around 15 at 200 F, so it probably won't make much of a difference either way... But I seem to recall a thread where people said the 5w40 made the engine a bit noisy.

Anyone with experience who could shed some light on the subject? Thanks in advance!

 

[GoldOxide_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.

 

[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.

Thanks. I imagine the 5w40 would give you a noticable improvement in gas mileage too.

 

[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.

I've used Rotella T6 synthetic for years in all my bikes with good result. When I got my 2013 CB1100 the transmission was a bit noisy and the shift from second to third balky at times. This continued with the 2nd an 3rd oil changes while I was using the Honda brand synthetic 10W-30. I got a factory service manual which said that 10W-40 oils were an acceptable alternative so next change I went back to my old favorite Rotella 5W-40. That was the end of the balky shift and a slight reduction in noise. Whether the Rotella oil was the solution or the transmission finally broke in I don't know. All modern oils are good but the Rotella can be found for so much less than branded motorcycle oils.

 

[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.

I've used Rotella T6 synthetic for years in all my bikes with good result. When I got my 2013 CB1100 the transmission was a bit noisy and the shift from second to third balky at times. This continued with the 2nd an 3rd oil changes while I was using the Honda brand synthetic 10W-30. I got a factory service manual which said that 10W-40 oils were an acceptable alternative so next change I went back to my old favorite Rotella 5W-40. That was the end of the balky shift and a slight reduction in noise. Whether the Rotella oil was the solution or the transmission finally broke in I don't know. All modern oils are good but the Rotella can be found for so much less than branded motorcycle oils.

I've used Rotella T6 synthetic for years in all my bikes with good result. When I got my 2013 CB1100 the transmission was a bit noisy and the shift from second to third balky at times. This continued with the 2nd an 3rd oil changes while I was using the Honda brand synthetic 10W-30. I got a factory service manual which said that 10W-40 oils were an acceptable alternative so next change I went back to my old favorite Rotella 5W-40. That was the end of the balky shift and a slight reduction in noise. Whether the Rotella oil was the solution or the transmission finally broke in I don't know. All modern oils are good but the Rotella can be found for so much less than branded motorcycle oils.
Yes. And the fact that my Shadow 750 runs noticably better on Rotella T4 than on Honda oil tells me that Honda is good at engineering motorcycles, while Shell is good at engineering motor oils.

I was looking at the 15w40 simply because of the increased shear resistance, and because the T6 supposedly flows very well at low temps for a 15w oil. If you folks are using the 5w40 T6 with good results, I am willing to go that direction too.

 

[Enzofour_imp]

I understand that Honda GN4 oil is semi-synthetic

 

[GoldOxide_imp]

I understand that Honda GN4 oil is semi-synthetic

This common version is conventional in North America:

 

[sonnyb_imp]

5W40 here as well with good results

 

[Yata-Garasu_imp]

5W40 here as well with good results

Thank you Sonny, I see that you're in Fort Worth, so pretty much the same climate as myself in Dallas. How many miles have you been running the T6? Did you ever consider the 15w40 version? Do you ride in the winter as well? What kind of drain interval are you using? Thanks for the reply!

 

[Yata-Garasu_imp]

Just a quick update.

Installed the 15w40 T6, full synthetic.

After running the dealer-installed GN4 10W40 for a season and averaging about 40 mpg, with an all time high of 46 mpg once, I was very pleased to see my mileage has improved to 50 mpg with my first full tank running the 15w40.

The old Honda GN4 10w40 had about 3500 miles on it, and had the viscosity of coffee when it came out.

I'm interested to see if the mileage will continue to be this good or if it's just a fluke.

Even comparing to my previous record of 46 mpg on the GN4, 50 mpg is almost a full 10% improvement. Compared to my average of 40 mpg, it's better than 20%!

I am not sure, but it's possible that the engine is a little louder with the 15w40 compared to 10w40. This could simply be an expectation bias as I anticipated that the 15w40 might be louder, and I was fully prepared to dump out the 15w40 immediately if the mileage was poor.

Luckily the mileage improved, so I will be sticking with the 15w40 for at least a little while longer.

I wanted to share my experience as there seems to be a bit of confusion on this topic, and even some fear mongering when it comes to using non-Honda oils.

I know a lot of people here use the 5w40 T6 instead of the 15w40. I picked the 15w40 due to it's improved sheer resistance, and the fact that I rarely ride below 32F, and never ride below 22F.

If the 15w40 had caused worse mileage, I was considering the 10w30 Rotella T4, a semi synthetic at the exact weight spec'd in the owners manual. If I was in a colder climate than Texas the 10w30 might be my go-to oil.

Anyhow, so far so good with the 15w40 T6.

 

[GoldOxide_imp]

If I lived in the oven-baked southwest states, I would maybe consider 15W40 T6 too - at least during the warm seasons.

 

[Yata-Garasu_imp]

If I lived in the oven-baked southwest states, I would maybe consider 15W40 T6 too - at least during the warm seasons.

Did you see my comment about the T4 10w30?

Depending on how many miles I ride this summer, I might winterize with the 10w30 just to have clean oil in the bike during the slow winter months.

Oddly, it's not available at Walmart, but it's $20 bucks a gallon at my local car parts stores.

 

[GoldOxide_imp]

If I lived in the oven-baked southwest states, I would maybe consider 15W40 T6 too - at least during the warm seasons.

Did you see my comment about the T4 10w30?

Depending on how many miles I ride this summer, I might winterize with the 10w30 just to have clean oil in the bike during the slow winter months.

Oddly, it's not available at Walmart, but it's $20 bucks a gallon at my local car parts stores.

Did you see my comment about the T4 10w30?

Depending on how many miles I ride this summer, I might winterize with the 10w30 just to have clean oil in the bike during the slow winter months.

Oddly, it's not available at Walmart, but it's $20 bucks a gallon at my local car parts stores.
I did. I can't comment on Rotella T4 10W30 (I realize it is MA/MA2 registered) because I can't seem to find any in Ontario, Canada. If I could, I would have used it by now.

 

[2014ltdltz]

Have not previously used Rotella in the past. Being located in a very hot climate, the OEM-recommended 10W-30 did not sit well with me. I was happier when I saw the service manual ok'd 10W-40 (at least there was a higher end viscosity commensurate with hotter temps, e.g., >100F ambient). That being said, once mine is a little more broken-in, I will entertain possibly using 15W-50 int he summer months. Oh, for clarity, with the exception of OEM break-in I use full synthetics in my motors across the board. Years ago, I recall seeing SAE data charts showing slightly lower engine temps with full synthetics versus standard mineral oils and that has always left an impression on me. Combined with judicious oil and filter changes, I have never had an internal engine component failure in any of my vehicles.

 

[Yata-Garasu_imp]

I dumped the T6 15w40 at 2600 miles.

Shifting was acceptable and the viscosity and color still seemed good, but the continued noise from the valves was bugging me, and I only got 35 mpg the last two tanks.

15w40 is fine in my Shadow VT750, but it doesn't seem to be a good fit for the CB1100, in my limited experience.

I refilled with 3.9 quarts of T5 10w30. The valve noise is gone and the shifting seems excellent so far, despite the T5 not having any official MA certs.

Hopefully the poor mileage was just caused by low tire pressure.

I'll update later once I've got more miles on the T5.

 

[GoldOxide_imp]

15W40 might be quite heavy for the CB1100, possibly even under Texas heat.

Rotella T5 is definitely not recommended for motorcycles with a wet clutch.

If you can find T6 10W40 you might be fine.

I used T6 5W40 in the heavy and hot summers in southern Ontario.

 

[Yata-Garasu_imp]

15W40 might be quite heavy for the CB1100, possibly even under Texas heat.

Rotella T5 is definitely not recommended for motorcycles with a wet clutch.

If you can find T6 10W40 you might be fine.

I used T6 5W40 in the heavy and hot summers in southern Ontario.

There's no T6 in 10w40.

There are a bunch of guys using T5 in their motorcycles at the oil forum Bob Is The Oil Guy. The evidence against using it seems more based on not having the MA letters on the bottle, while the evidence for it seems to be based on actual real world experience.

100 miles in and my CB1100 seems to like it, but I will definitely be keeping a close eye on it, and will update the forum with my experience.

 

[GoldOxide_imp]

15W40 might be quite heavy for the CB1100, possibly even under Texas heat.

Rotella T5 is definitely not recommended for motorcycles with a wet clutch.

If you can find T6 10W40 you might be fine.

I used T6 5W40 in the heavy and hot summers in southern Ontario.

There's no T6 in 10w40.

There are a bunch of guys using T5 in their motorcycles at the oil forum Bob Is The Oil Guy. The evidence against using it seems more based on not having the MA letters on the bottle, while the evidence for it seems to be based on actual real world experience.

100 miles in and my CB1100 seems to like it, but I will definitely be keeping a close eye on it, and will update the forum with my experience.

Regarding T5, you could be right with supporting empirical evidence.

Nonetheless, since there is no MA/MA2 certification, there is no assurance that the T5 recipe won't change (small adjustments) and be/remain in favour of wet clutches. Shell won't be responsible for any side-effects since it is not formally approved for general motorcycles. Maybe no certification has something to do with how the T5 semi-synthetic (?) is concocted? Maybe there are other issues that have nothing to do with wet clutches, like burned particulates and sensors/catalyzing, etc. (don't know)

On the other hand, T6 explicitly declares the certification.

 

[Yata-Garasu_imp]

15W40 might be quite heavy for the CB1100, possibly even under Texas heat.

Rotella T5 is definitely not recommended for motorcycles with a wet clutch.

If you can find T6 10W40 you might be fine.

I used T6 5W40 in the heavy and hot summers in southern Ontario.

There's no T6 in 10w40.

There are a bunch of guys using T5 in their motorcycles at the oil forum Bob Is The Oil Guy. The evidence against using it seems more based on not having the MA letters on the bottle, while the evidence for it seems to be based on actual real world experience.

100 miles in and my CB1100 seems to like it, but I will definitely be keeping a close eye on it, and will update the forum with my experience.

Regarding T5, you could be right with supporting empirical evidence.

Nonetheless, since there is no MA/MA2 certification, there is no assurance that the T5 recipe won't change (small adjustments) and be/remain in favour of wet clutches. Shell won't be responsible for any side-effects since it is not formally approved for general motorcycles. Maybe no certification has something to do with how the T5 semi-synthetic (?) is concocted? Maybe there are other issues that have nothing to do with wet clutches, like burned particulates and sensors/catalyzing, etc. (don't know)

On the other hand, T6 explicitly declares the certification.

Regarding T5, you could be right with supporting empirical evidence.

Nonetheless, since there is no MA/MA2 certification, there is no assurance that the T5 recipe won't change (small adjustments) and be/remain in favour of wet clutches. Shell won't be responsible for any side-effects since it is not formally approved for general motorcycles. Maybe no certification has something to do with how the T5 semi-synthetic (?) is concocted? Maybe there are other issues that have nothing to do with wet clutches, like burned particulates and sensors/catalyzing, etc. (don't know)

On the other hand, T6 explicitly declares the certification.
T5 has Molybdenum in it. Just a touch, about 100 ppm. In higher concentrations Moly is not good for wet clutches, but at the low levels in T5, it shouldn't be an issue.

But that's a good point that Shell could change the formula and not worry about how it affects motorcycles. So far, the T5 10w30 is outperforming both the T6 15w40 and the Honda GN4 10w40.

I thought long and hard before taking the T5 plunge. So far so good, but the jury's still out.

I just got home from running errands, gonna take my "Crow Bike" for a spin!

 

[GoldOxide_imp]

Good to know Yata-Garasu.

Always nice to have another option in case Rotella T6 is not for some.