The Use of 5W Motorcycle Oils

[Analyzer]

This isn't to start a hectic debate or condemn anyone, but I'm curious what everyone thinks about the use of a 5W motorcycle oil, like Rotella T6, Castrol Power RS, Motorex, etc ? I've been contemplating the use of T6 in one of my bikes after seeing some promising UOA's (currently testing out the Rotella 15W40), while also noticing some UOA's with higher wear rates (given, this could be due to a range of possibilities from OCI, type of motorcycle, how hard the bike is ridden or raced, etc. which I'm not including in the analysis of the oil).

Given that the T6 has been shown to be fantastic for various gas and diesel applications, I'm wondering if it fares as well for motorcycle use with a shared transmission. Of course once the oil is up to operating temperature it is no longer 5W but equivalent to a 40, but what I'm curious about is during cold start up is the 5W offering enough protection and acting as a thick enough lubricant and providing enough oil film strength to contend with the engine, gearbox, clutch, higher rpm's, and more severe engine conditions when compared to a gasoline/diesel engine alone?
I've looked at nearly every major motorcycle manufacturer from Yamaha, Honda, Kawasaki, Suzuki, BMW, Ducati, etc. and found that out of all of them, BMW is the only one that manufacturers an oil below a 10W (in this case a 5W40) that is to be used within certain year ranges of BMW's. I found many other oils from these companies: 10W30, 10W40, 10W50, 15W30, 15W50, 20W50, but again, no mention of the use of a 5W oil, not to mention the void of the warranty if used during that time frame.
Since motorcycles don't have to conform to CAFE requirements because of their high fuel efficient nature (thus negating one reason to use a thinner oil for improved fuel economy), and since most oil in motorcycles have to not only lubricate the engine, but also the clutch and gearbox, plus the greater demands of the motorcycle itself, is this the reason nearly all the manufacturers mandate the use of at least a 10W oil?

Just wanted to get everyone's thoughts and opinions on the subject.

 

[Astro14]

5W at start up is hundreds of times thicker than 40 at operating temperature...so, I don't really understand your concern...except that the manufacturers aren't recommending that viscosity...a 5W40 will be fine, as long as other parts of the spec are met...with the clutch/trans sharing the oil, that would be more my concern...

 

[Cardenio327]

I commute daily on a 400cc Honda. I change the oil once a year, last February I put Helix Ultra 5w-40 in it. Next February I plan to use some leftover M1 EP 5w-50 that I still have from the SM to SN changeover. I have not noticed any clutch slipping or rougher than usual shifting. Honda has back-specced all 2004 and newer cycles to 10w-30 oil, I really doubt a quality 5w-40 will shear down to a lower viscosity than a quality 10w-30 will. I am of the opinion that even if the oil is sheared out of grade or diluted with fuel, the engine will last longer than the rest of the cycle anyway.

 

[Analyzer]

Originally Posted By: Astro14
5W at start up is hundreds of times thicker than 40 at operating temperature...so, I don't really understand your concern...except that the manufacturers aren't recommending that viscosity...a 5W40 will be fine, as long as other parts of the spec are met...with the clutch/trans sharing the oil, that would be more my concern...


You're absolutely right that the 5W at start-up is significantly thicker than the 40 at operating temp, but with that in mind how much thicker would the 10W be at start-up in comparison? That's what I'm curious about, have the motorcycle manufacturers investigated this and determined the 5W didn't offer enough protection or film strength and that's why they don't offer anything below a 10W? (I know, it's a question I wish I could ask the engineers that designed them lol).

Cardenio327, I'm more interested in the cold viscosity of the oil rather than the operating temperature viscosity. It's true there are more oils out there than not that experience shear within a motorcycle (sunruh can definitely attest to that! lol), and that will vary depending on base stock, the amount/type of VII's they include; plus fuel dilution and other factors as you stated. That's what has got me thinking, will the 10W provide better startup/initial operating protection over the 5W, and have the manufacturers looked into it?

 

[tc1446]

Analyzer: BRP uses a synthetic 5w-40 for winter and sells it under their name for use in their Spyders. A lot of owners also use the BRP 10w-40 which is a blend. Both oils are believed to
be packaged for them by Castrol.

 

[Brent_G]

I have ran t6 multiple times in both a 07 gsxr 600 and in my r1 without a single issue. Also ran t6 for 50 hours in my 09 450r quad that put down 57hp on the dyno. Wear was almost nothing and I am still running that cylinder/piston. That engine is used solely for flat track running near rev limit.

 

[rrguy]

Actually motorex recomended for factory KTM & Canam both have a 5w 40 oil availible. Motorex a quality oil even has a 0-40 oil like amsoil. In recent years I admire KTM & Canams engineering above any of the major 4. The quality thinner oil creates less clutch drag & smoother shifts in cclose tolerance well built gearbox IMO. Amsoil motorcycle 0w-40 actually fixed some clutch drag in a GASGAS 8 plate clutch I had. The old formula of 5w-40 Rotella I used often, but the new energy conserving formula T6 I don't use cause of some oil guru advice.

 

[Analyzer]

Originally Posted By: tc1446
Analyzer: BRP uses a synthetic 5w-40 for winter and sells it under their name for use in their Spyders. A lot of owners also use the BRP 10w-40 which is a blend. Both oils are believed to
be packaged for them by Castrol.


tc1446, very true! I found Bombardier , Yamaha, and others that also manufacture watercraft, snowmobiles, and ATV's usually have a 5W40 engine oil available for those specific applications; but interestingly those oils weren't specified for motorcycle use.

 

[rrguy]

COPIED
Moterex Fully synthetic racing oil developed by motorex racing lab with crescent suzuki/rizla suzuki team in the british superbike championshipthe 0w40

Id say that oil should hold up for you avg street rider lol
The design of say an atv sport quad engine Is similair to street bikes & probably sees more abuse than most IMO.

 

[Analyzer]

Originally Posted By: rrguy
Actually motorex recomended for factory KTM & Canam both have a 5w 40 oil availible. Motorex a quality oil even has a 0-40 oil like amsoil. In recent years I admire KTM & Canams engineering above any of the major 4. The quality thinner oil creates less clutch drag & smoother shifts in cclose tolerance well built gearbox IMO. Amsoil motorcycle 0w-40 actually fixed some clutch drag in a GASGAS 8 plate clutch I had. The old formula of 5w-40 Rotella I used often, but the new energy conserving formula T6 I don't use cause of some oil guru advice.


Your right KTM does approve the use of Motorex in their motorcycles, but the most common oil grade tends to be 10W50, with only a select few KTM's recommending the use of 5W40 in under 32 degree weather. Bombardier and Can-Am (including some BMW's) get their motors from Rotax, which uses 5W40 in many watercraft, and uses it as an optional weight for the Spyders. The Amsoil 0W40 is meant for 4-stroke recreational motors, ATVs, and snowmobiles. They make 4 options of approved motorcycle oil, the 10W30, 10W40, 20W50, and an uber thick SAE 60 for old school Harley's.

http://www.ktm-parts.com/pdf/TechBull/TB0802.pdf

 

[Cardenio327]

Originally Posted By: Analyzer
Cardenio327, I'm more interested in the cold viscosity of the oil rather than the operating temperature viscosity. It's true there are more oils out there than not that experience shear within a motorcycle (sunruh can definitely attest to that! lol), and that will vary depending on base stock, the amount/type of VII's they include; plus fuel dilution and other factors as you stated. That's what has got me thinking, will the 10W provide better startup/initial operating protection over the 5W, and have the manufacturers looked into it?


I started using 5w oils because of an obnoxious valvetrain rattle my RFVC engine has had since new. It rarely if ever rattles on 5w, rattled occasionally on 10w and rattled horribly on every cold start regardless of ambient temperature with 15w. My take on that is the thinner the cold viscosity, the faster it pumps up to the head, the less cam wear can occur, so in my opinion on the cold end of the operating spectrum 5w protects more than 10w.

 

[LoneRanger]

Originally Posted By: Analyzer
This isn't to start a hectic debate .............


I bet it does anyhow.

 

[rossn2]

I thought I read somewhere, Rotella does not recommend using T6 in a motorcycle wet clutch or shared-sump application?

 

[CATERHAM]

Originally Posted By: Cardenio327
Originally Posted By: Analyzer
Cardenio327, I'm more interested in the cold viscosity of the oil rather than the operating temperature viscosity. It's true there are more oils out there than not that experience shear within a motorcycle (sunruh can definitely attest to that! lol), and that will vary depending on base stock, the amount/type of VII's they include; plus fuel dilution and other factors as you stated. That's what has got me thinking, will the 10W provide better startup/initial operating protection over the 5W, and have the manufacturers looked into it?


I started using 5w oils because of an obnoxious valvetrain rattle my RFVC engine has had since new. It rarely if ever rattles on 5w, rattled occasionally on 10w and rattled horribly on every cold start regardless of ambient temperature with 15w. My take on that is the thinner the cold viscosity, the faster it pumps up to the head, the less cam wear can occur, so in my opinion on the cold end of the operating spectrum 5w protects more than 10w.

What you're really doing to in comparing 5W vs 10W vs 15W oils (you could have included 0W and 20W as well) during start-up in a warm climate has nothing to do with an oil's extreme cold performance but rather how thick these oils are at more typical start-up temp's.
Generally 0W oils have a higher viscosity index than 5W oils which is higher than 10W oils etc and higher V.I. oils are lighter on start-up. Of course the second number of an oil grade, 30, 40 or 50, representing viscosity ranges at operating temp's will also have a big effect on the start-up viscosity.
A 5W-30 will be lighter on start-up than a 5W-40 which will be lighter than a 5W-50.

So one very easy way to compare the relative start-up viscosities of all oils regardless of their grade is to look to their PDS spec's, and check what an oil's viscosity is at 40C.
40C (104F) is pretty warm but it's still cold for an engine and it's low enough that an oil with a lower viscosity at 40C will also be lower at 20C and even 0C.
It's not perfectly accurate because it's not taking an oil's V.I. into consideration but it's a good ball park guide. If two oils have similar KV40 spec's then you need two compare their V.I.s but cutting the relative start-up viscosity comparison finer than is generally necessary.

 

[Analyzer]

Cardenio327-That's interesting about the valve-train noise, what is the recommended viscosity for your 400 in the Honda manual? It is true that thinner weight oils can have easier pump-ability on start up, and while that might reach your valve-train sooner, does that offer enough protection and film strength for other engine internals and the gearbox over tens of thousands of miles? That's the main question I'm trying to get at. My brother for instance has a Masters in Auto Engineering and Technology and is an ASE Master Mechanic. In one of his more recently purchased vehicles it stated the use of a 5W30, which he used a full synthetic and changed religiously. He decided to try out a synthetic 0W-30 (I believe it was Mobil 1) for easier pump-ability and fuel economy, but had such bad valve-train clatter from the reduced viscosity that he dropped the oil after not even reaching 100 miles and went back to 5W30. It's definitely easier for cars to run a lower viscosity (hence the use of some 0/5W-20) because we have a separate transmission. I'm not tying to doubt your use of the 5W40 in your Honda, just trying to present another side of the coin. Off topic, how's the weather down in Mexico? I'm in SoCal and was shocked with the cold snap we had these past 2 weeks, did you guys get similar or was it out of reach?



rrguy- Yeah, lots of superbike and motogp teams tend to run thinner grades of oil to reduce the drag that oil has on an engine's internal reciprocating components and gain a few horsepower. Motul makes a race specific 5W30, Maxima Maxum Ultra made a 0W30 & 5W30 too. The only thing I wonder about the use of these oils is whether or not it would protect a motorcycle engine/gearbox over 20-30,000 miles and up, where as the race motors are being worked on continuously and oil being drained frequently after the harsh race conditions.

 

[CATERHAM]

Analyzer, from my Bike riding days, one easy way of determining if the oil you're using is getting to thin when the engine is hot, is a noticeable reduction is shift quality. Shifting become very notchy and if the oil gets very hot it can be very difficult to shift at all.
So if you can maintain good shift quality on a 0W/5W-30 oil you don't need to run anything heavier.

 

[sunruh]

maxima used to make an "ultra 0w10"

http://www.chaparral-racing.com/Product/maxima-maxum4-ultra-oil-0w10/353-0717.aspx

 

[Cujet]

T6 is a commonly used oil in motorcycles. Regardless of the manufacturers specifications. Most people give it high marks. And, I don't recall ever reading any sub standard results, other than the possibility of slightly more rapid shearing. Many of the "tour" guys do with with fantastic UOA results.

I'm convinced that shared sump motorcycle engines should have frequent oil changes for all the expected reasons. Shear, particulate count, iron, clutch material, etc. With that in mind, I'm not at all of the mindset that you need an oil that is 100% shear stable for 15,000 miles when the oil should come OUT at 2500 miles!

 

[Cujet]

Originally Posted By: CATERHAM
Analyzer, from my Bike riding days, one easy way of determining if the oil you're using is getting to thin when the engine is hot, is a noticeable reduction is shift quality. Shifting become very notchy and if the oil gets very hot it can be very difficult to shift at all.
So if you can maintain good shift quality on a 0W/5W-30 oil you don't need to run anything heavier.


It's interesting how oil "talks" to us, isn't it? Not sure that's a 100% scientific method, but I believe it has validity. My SV1000s certainly likes frequent oil changes, and the shifting starts "going south" after about 1500 miles. Even with top shelf, full syn oils.

 

[Clevy]

Originally Posted By: Analyzer
This isn't to start a hectic debate or condemn anyone, but I'm curious what everyone thinks about the use of a 5W motorcycle oil, like Rotella T6, Castrol Power RS, Motorex, etc ? I've been contemplating the use of T6 in one of my bikes after seeing some promising UOA's (currently testing out the Rotella 15W40), while also noticing some UOA's with higher wear rates (given, this could be due to a range of possibilities from OCI, type of motorcycle, how hard the bike is ridden or raced, etc. which I'm not including in the analysis of the oil).

Given that the T6 has been shown to be fantastic for various gas and diesel applications, I'm wondering if it fares as well for motorcycle use with a shared transmission. Of course once the oil is up to operating temperature it is no longer 5W but equivalent to a 40, but what I'm curious about is during cold start up is the 5W offering enough protection and acting as a thick enough lubricant and providing enough oil film strength to contend with the engine, gearbox, clutch, higher rpm's, and more severe engine conditions when compared to a gasoline/diesel engine alone?
I've looked at nearly every major motorcycle manufacturer from Yamaha, Honda, Kawasaki, Suzuki, BMW, Ducati, etc. and found that out of all of them, BMW is the only one that manufacturers an oil below a 10W (in this case a 5W40) that is to be used within certain year ranges of BMW's. I found many other oils from these companies: 10W30, 10W40, 10W50, 15W30, 15W50, 20W50, but again, no mention of the use of a 5W oil, not to mention the void of the warranty if used during that time frame.
Since motorcycles don't have to conform to CAFE requirements because of their high fuel efficient nature (thus negating one reason to use a thinner oil for improved fuel economy), and since most oil in motorcycles have to not only lubricate the engine, but also the clutch and gearbox, plus the greater demands of the motorcycle itself, is this the reason nearly all the manufacturers mandate the use of at least a 10W oil?

Just wanted to get everyone's thoughts and opinions on the subject.
Originally Posted By: Analyzer
This isn't to start a hectic debate or condemn anyone, but I'm curious what everyone thinks about the use of a 5W motorcycle oil, like Rotella T6, Castrol Power RS, Motorex, etc ? I've been contemplating the use of T6 in one of my bikes after seeing some promising UOA's (currently testing out the Rotella 15W40), while also noticing some UOA's with higher wear rates (given, this could be due to a range of possibilities from OCI, type of motorcycle, how hard the bike is ridden or raced, etc. which I'm not including in the analysis of the oil).

Given that the T6 has been shown to be fantastic for various gas and diesel applications, I'm wondering if it fares as well for motorcycle use with a shared transmission. Of course once the oil is up to operating temperature it is no longer 5W but equivalent to a 40, but what I'm curious about is during cold start up is the 5W offering enough protection and acting as a thick enough lubricant and providing enough oil film strength to contend with the engine, gearbox, clutch, higher rpm's, and more severe engine conditions when compared to a gasoline/diesel engine alone?
I've looked at nearly every major motorcycle manufacturer from Yamaha, Honda, Kawasaki, Suzuki, BMW, Ducati, etc. and found that out of all of them, BMW is the only one that manufacturers an oil below a 10W (in this case a 5W40) that is to be used within certain year ranges of BMW's. I found many other oils from these companies: 10W30, 10W40, 10W50, 15W30, 15W50, 20W50, but again, no mention of the use of a 5W oil, not to mention the void of the warranty if used during that time frame.
Since motorcycles don't have to conform to CAFE requirements because of their high fuel efficient nature (thus negating one reason to use a thinner oil for improved fuel economy), and since most oil in motorcycles have to not only lubricate the engine, but also the clutch and gearbox, plus the greater demands of the motorcycle itself, is this the reason nearly all the manufacturers mandate the use of at least a 10W oil?

Just wanted to get everyone's thoughts and opinions on the subject.




Originally Posted By: rossn2
I thought I read somewhere, Rotella does not recommend using T6 in a motorcycle wet clutch or shared-sump application?



Really? Why exactly would they stamp the label with the JASO label if they didn't think it was able.

That being said I used t-6 in my Yamaha 1100 v-star and you could time the life of it with a stopwatch. It shears so fast in a single ride my bike would go from sewing machine to tap dancing.
The best bike oil for the money is rotella 15w-40 conventional. I'll never go back to paying 10 bucks or more a quart for oil ever again.
The cost of changing my bikes oil with amsoil is more than a 5 gallon pail of rotella costs and the pail lasts all year long.