Saw an Africa Twin in the wild about to get on the ferry to Victoria BC from Vancouver BC. Bikes get to go to the front of the line. Sell the house, and cars. Get on the road!
New to me... DCT.... Africa Twin
- Thread starter BigJohn
- Start date
I would suggest you have repeated the same thing twice in this thread, and didn't read that BigJohn doesn't go with thin oil for high comp engines, yet you posted Rotella makes 10w30 in two varieties after he was clear he doesn't care about thin oils. A few guys are cut and paste without an original thought. Other guys say the same thing based on experience and repeat it because it's worth noting for guys that argue success.
My 2014 CB1100 loves it. Very smooth shifting and seems to be long lasting.
I put 4k miles on it the first year with no hiccups, and the oil still seemed viscous when I changed it, unlike the Honda GN4 10w40, which had sheared down to coffee water with similar mileage.
BTW, T5 10w30 now has JASO Ma2 on the label. The oil didnt change, Shell just updated the jug.
Interesting video in this link.
Look forward to hearing from those that watch it sharing the results and how it verifies/denies the mantra/thoughts on using thinner oil that comes up in about every thread.
Pay attention to windage losses and start up wear numbers.
Look forward to hearing from those that watch it sharing the results and how it verifies/denies the mantra/thoughts on using thinner oil that comes up in about every thread.
Pay attention to windage losses and start up wear numbers.
Only a few motorcycle OMs call out a xW-30 oil as an option, and it typically doesn't include use in higher ambient temperatures. There's a reason most motorcycles spec xW-40 and xW-50 grade engine oils ... for added engine wear protection and because CAFE doesn't have their hooks in the motorcycle manufactures ... yet.
Last edited:
Agree, this is directed at the mantra about thin oil that pops up predictably, and am looking forward to the counter to this information.
I'd never run a xW-30 oil in a motorcycle, even if the owner's manual showed it as an option. The reason being, that a thicker oil provides more film thickness between moving parts compared to a thinner oil. The oil film thickness is the primary way that wear from rubbing is controlled. I want the oil film to have some wear protection headroom, and don't care about losing a few HP at full engine output. I don't race my bikes at constant full bore throttle, but just some short bursts of full acceleration episodes, so I'd never detect the difference of a few less HP at redline.
Last edited:
I have always been on that same page you are. Need the MOFT. The video gives some good info in a controlled test that supports it. Not cut and pasting the same info that has been done over and over for a decade or more.
Call it a challenge for that crew to refute the premise of "more power" with lighter oil when the lighter oil test was losing power as it flows faster back into the pan when hot and creates windage loss. The heavier oil did not have the windage loss when it was up to temperature on the dyno.
The wear info numbers are counter to the premise of lighter oil having less wear at start up as well in that test.
I found it interesting the wear numbers with a prefilled vs dry spin on filter justified prefilling when using the lighter oil, but no discernible benefit when using heavier oil.
Call it a challenge for that crew to refute the premise of "more power" with lighter oil when the lighter oil test was losing power as it flows faster back into the pan when hot and creates windage loss. The heavier oil did not have the windage loss when it was up to temperature on the dyno.
The wear info numbers are counter to the premise of lighter oil having less wear at start up as well in that test.
I found it interesting the wear numbers with a prefilled vs dry spin on filter justified prefilling when using the lighter oil, but no discernible benefit when using heavier oil.
Most of the "cut and paste" info that says the lower the viscosity, the lower the MOFT and the more possible engine wear as a result has always been true. It's a physical phenomena the thicker oil creates a thicker film thickness between moving parts which helps reduce wear from surfaces rubbing together. This has been know ever since mankind figured out Tribology which as been around for over 100 years.
Yes, that part was interesting. But every motor may have different windage characteristics.
Even "thin" oil is relatively thick when cold or at room temperature.
I've always pre-fill oil filters as much as possible. Why not if you're careful doing it.
Not all 30 grades are created equal. HTHS values can vary from 2.9 to 3.5
Last edited:
Yes, but it cant be 3.5+ ... if it's 3.5 or greater cP it would be a 40 grade per J300. Trying to find a xW-30 JASO rated motorcycle oil with near 3.5 cP HTHS might be a chore. So I'd just go with xW-40 since there are lots of those oils available meeting the motorcycle wet clutch JASO rating. Honda makes/has a xW-30 motorcycle oil, so it would be interesting to see what the HTHS is on that. Still rather just go for a xW-40.
Last edited:
Zee, good points.
The thin oil had more wear at start up, thicker oil had less. With respect to thin/thick at ambient temp the info is relative to compare thinner and thicker oils at start up, IMO.
With respect to different engines and windage characteristics: I cannot visualize a situation where as an engine warms up and thicker oil warms up, that windage losses would increase vs the thinner oil as it warms up if in fact it's the rapid return to the sump that causes the issue. Thin oil would logically always create more of that issue.
The cut and paste is painting the scenario that more flow regardless and less resistance internally regardless is a better oil choice. That has always created a false narrative with respect to this discussion and leads to misinformation being propagated.
The thin oil had more wear at start up, thicker oil had less. With respect to thin/thick at ambient temp the info is relative to compare thinner and thicker oils at start up, IMO.
With respect to different engines and windage characteristics: I cannot visualize a situation where as an engine warms up and thicker oil warms up, that windage losses would increase vs the thinner oil as it warms up if in fact it's the rapid return to the sump that causes the issue. Thin oil would logically always create more of that issue.
The cut and paste is painting the scenario that more flow regardless and less resistance internally regardless is a better oil choice. That has always created a false narrative with respect to this discussion and leads to misinformation being propagated.
Some of that windage loss in that engine might be based on how the oil from the heads drains back to the sump. I think they mentioned something about that in the video. A good engine designer would ensure that the oil draining back from the heads isn't hitting the rotating crankshaft and causing undue windage losses.
Yeah, people thinking thinner oil is better because of "more flow" or "less resistance internally" (only really important for cold start-ups) forget that the most important aspect of oil is to keep moving parts separated more than not for parts in hydrodynamic and mixed boundary lubrication. The other side of that coin is the AF/AW package in the oil to help reduce wear when the oil film thickness goes to zero because the oil viscosity wasn't thick enough and/or the relative speed between moving parts goes to zero and the film disappears. An adequate oil volume will always get to moving part by the positive displacement oil pump, unless the oiling system is not properly designed. What's more critical in looking at "flow rate" of the oil is to ensure you pick the proper W rating for cold startups based on the ambient temperatures the machine is used in.
