Straight Weight / Monograde

[Overfill]

The other day I spent some time waiting for a register inside a gas station. Whiile inside I saw bottles of Pennzoil SAE 40 (i.e. Heavy Duty / containing detergents).
Another post this year showed good results using straight weight racing (VR1) SAE 40.

Has anyone tried using HD monogrades in a shared sump bike?

Just pondering the idea, can you mix part of a straight weight with a multigrade HDEO to manage shearing losses?

Lastly, any UOA/VOA on monograde HD Pennzoil/ Castrol/ QS monogrades?

 

[nthach]

HD monogrades are now formulated with API SN add packs, I'd be leery running those in a bike since SM/SN oils have more friction modifiers in the interest of MPG. VR1/Delo 400/Rotella monogrades are one-offs that don't need to comply with the latest specs.

 

[ragtoplvr]

A straight weight will have a horrible clunk when going from neutral when cold. Shifting will Be very stiff for the first few miles, and missed shifts may be common.

 

[joe02151]

I personally just ran 3 oil changes of SAE 40 VR1 oil in my 2017 yamaha r1, the bike is a shared sump and I have great results with it, I need to point out that I live in south florida so the bike never sees weather below 70-80F, the manual calls for 10w40 or 15w50. The VR1 has the smoothest shifting out of all the other oils I've used in this bike. also I have not experienced any clutch slipping.

 

[joe02151]

https://www.bobistheoilguy.com/foru...voline-vr1-sae-40-4000-miles#Post4835587

 

[ragtoplvr]

i guess i have requirements, i have always ridden down to mid 20;s

 

[Chris142]

Originally Posted by ragtoplvr
A straight weight will have a horrible clunk when going from neutral when cold. Shifting will Be very stiff for the first few miles, and missed shifts may be common.

My quad shifted great with napa sae 40 in it. I was worried about how slow it would pump up to the cam. So I drained it.

 

[Silk]

I'm using SAE30 in a couple of my bikes. One is shared sump, and was originaly recommended for 20/30, (1974) so pretty close. It has a very wide 3 gear helical primary, which would be a shear factory. Goes very well on it. I've also just put 30 in my Airhead...BMW recommends it from zero to 30C, right in my temp zone. I've done less than 1,000km on it, but seems to still be running. I'll be putting it to a lot more use over summer....and I'm sure it will be up to it.

 

[jeff78]

Originally Posted by Chris142
Just pondering the idea, can you mix part of a straight weight with a multigrade HDEO to manage shearing losses?


You could, but it's just a matter of whether it's worth the extra time/effort to get the proportions right, assuming you know what the final mix will be.

In other words, if your engine is known to be a shear monster and shifting gets bad partway through your intended OCI, then just run a straight monograde and be done with it (environmental conditions allowing, of course).

 

[Overfill]

Originally Posted by jeff78
Originally Posted by Chris142
Just pondering the idea, can you mix part of a straight weight with a multigrade HDEO to manage shearing losses?


You could, but it's just a matter of whether it's worth the extra time/effort to get the proportions right, assuming you know what the final mix will be.

In other words, if your engine is known to be a shear monster and shifting gets bad partway through your intended OCI, then just run a straight monograde and be done with it (environmental conditions allowing, of course).


I would say it is.
To be completely honest though, a lot of this is just interest driven.
OTOH, A few of the bikes I would like to trade up for are the worst shear monsters; I wanna know how I can handle it.

 

[sunruh]

i've tested sae30, sae40, sae50 and sae60 (darn thick)
sae40 was miles better than 10w40 and megamiles better than 5w40 in susvis retention!
ambient temp will say which you should use.
however, i would pick a poor 20w50 over any 10w40 (and friends dont let friends use gtx20w50)

 

[Overfill]

I was also digging to see if PCMO 20w-50 are shear stable today (The SN or 2010 and later blends.)
I guess not.

 

[alarmguy]

Straight weight 40 will be fine if you ride in temps above 50 degrees it will be no different then 20/50.
See the UOA from another poster in here. Not sure of the hysteria over if a SN oil is safe, answer would be yes but for less then $5 or $4 a quart you can buy motorcycle oil from Walmart and not have to think about it. Valvoline 10/40 or 20/50 pick your favorite.

Someone calculated 20/50 viscosity is the same as straight 40 weight oil at roughly 50 to 60 degrees, so it would make sense if you have a shared sump bike. Though the UOA he posted was not all that impressive, so I have no idea if this thinking is correct but you can always try it.

 

[alarmguy]

Originally Posted by sunruh
(and friends dont let friends use gtx20w50)


Why? Just Curious ____

 

[jeff78]

Originally Posted by alarmguy
Someone calculated 20/50 viscosity is the same as straight 40 weight oil at roughly 50 to 60 degrees


Straight 40 is thinner than 20W-50 above freezing. Significantly below that, the 20W-50 (or pretty much any other multigrade) will be thinner.

 

[jeff78]

Originally Posted by Brian553

To be completely honest though, a lot of this is just interest driven.
OTOH, A few of the bikes I would like to trade up for are the worst shear monsters; I wanna know how I can handle it.


There aren't really too many options:

- Climate permitting, you can run a monograde and never worry about shear
- Run a multigrade that is known to be shear-resistant, maybe even one viscosity grade higher
- Frankenbrew a monograde with a multi and do UOA's to see what you're actually getting
- Shorten your OCI's

 

[alarmguy]

Very interesting subject, one that I have only become aware of by someone in this forum a few weeks ago, or maybe better said, never really much thought about it as I needed a multigrade oil in my cars since they are used in very cold weather.

BUT, my motorcycle is NEVER, EVER rode when its below 50 degrees and most times closer to 60 degrees.
I suspect MANY other rides are the same and for those that are, and IF you have a shared sump, simply just use mono/straight weight 40 oil, done, finished, no debate, you will never have your oil shear down.

I never realized mulltigrade oils never made much difference until you get around/ below 50 degrees and at 60 degrees your good.
Many bikers debate the shearing thing endlessly and for much of the country, all you need is a 30 or 40 straight weight, no debate, done. )
Actually for me I can use a straight 50 weight, even Harley sells one. Heck they sell a 60 too.

Interesting chart 10C = 50F & 20C = 68F

 

[alarmguy]

Originally Posted by jeff78
Originally Posted by alarmguy
Someone calculated 20/50 viscosity is the same as straight 40 weight oil at roughly 50 to 60 degrees


Straight 40 is thinner than 20W-50 above freezing. Significantly below that, the 20W-50 (or pretty much any other multigrade) will be thinner.



I dont think so, this chart shows a straight 30 oil thicker then a 5/40 and 10/40 @ 50F/10C which is way above freezing and viscosity darn close to a 10/60 at that temperature.
So I would go back to my original statement of what someone else posted in here. 20/50 roughly the same as 40 at 50 to 60F
Click -The graphs to the right make it easy to compare.
10C=50F and 20C=68F

Either way, its changed my whole way of thinking about multigrades in a bike, really not needed if you live ride above 60 degrees.

 

[jeff78]

Originally Posted by alarmguy

I dont think so, this chart shows a straight 30 oil thicker then a 5/40 and 10/40 @ 50F/10C which is way above freezing and viscosity darn close to a 10/60 at that temperature.


Numbers matter. We were talking about a straight 40 vs 20W-50, not a 30 vs 10W-40 or 5W-40. BTW, that 30 is thinner than the 15W-40 at freezing. So you can see that the W rating makes a difference once temps get low.


For a 40 vs. 20W-50, here are some kinematic viscosity numbers, pulled directly from the VR-1 data sheet and using a viscosity calculator:

(viscosity @ 40c, viscosity @ 100c, calculated viscosity @ 0c)

SAE 40: 136.8, 14.5, 2481.617
20W-50: 181.8, 20.5, 2675.548


Quote
So I would go back to my original statement of what someone else posted in here. 20/50 roughly the same as 40 at 50 to 60F


I don't remember seeing anyone saying that, do you have a link?

I do remember posting a UOA of SAE40 and you questioned what the point of running a monograde was, and I explained. It was where I mentioned that I did the calcs and the 40 was thinner than 20W-50 above freezing.

https://www.bobistheoilguy.com/foru...voline-vr1-sae-40-4000-miles#Post4835587

 

[jeff78]

For the sake of completeness, VR-1 SAE 40 vs a number of other xW-50 oils:

Code
Viscosity @ 40C 100C 0C 10C 20C 30C



VR-1 SAE 40: 136.8 14.5 2481.617 1013.444 470.409 242.748

VR-1 20W-50: 181.8 20.5 2675.548 1180.308 580.445 312.64

Valv M/C 20W-50: 169.4 20 2322.343 1048.171 525.342 287.478

M1 V-Twin: 172.3 20.8 2254.214 1033.904 524.818 290.089

M1 15W-50: 125 18 1266.482 629.873 342.281 200.414

VR-1 SAE 50: 219.3 20 4697.106 1828.742 812.788 403.243


So the VR1 SAE 40 is a little thinner than its 20W-50 sibling and a little thicker than some other 50's at freezing, but practically speaking these are all in the same ballpark (i.e. they'll crank and pump the same) with the exception of the Mobil 1 15W-50. The SAE 50 is in there as another outlier.