Can anyone explain why Harley recommends a diesel

[alarmguy]

Originally Posted By: BigCahuna

It still doesn't explain why Harley as a manufacturer doesn't list a spec from an API rated oil like they used to. They changed from recommending a SG rated oil, to diesel oil with ratings for things that a Harley motor doesn't need or require....,,

A couple other thoughts, just thoughts, at what point did HD go from SG to CH4? Was there a change in engine oil lubrication system, fuel injection or when they came out with the twin cam design? Also when someone says there are more robust add packages in S rated oils but what criteria does one use, clearly not everything is in a UOA and how it works in any particular engine, if using UOAs one can go take a quick look in the UOA of Redline on the first page of the motorcycle UOAs, it's got one [censored] of an add pack but the results of the UOAs are not impressive at all and HD360 delivered far better results along with other oils. When looking at automobile UOAs one can see stellar results from oils that test with far, far lower ad packs... Again... Not debating, just thoughts.

 

[alarmguy]

Well said DR

 

[kmrcstintn]

this might be a bit simplistic... a Harley owner is out on a long trip and discovers he/she is low on oil and didn't pack an extra quart; not everywhere that sells oils will have motorcycle specific oil & might be more likely to carry diesel oil along with car oil; the car oil will have the correct viscosity (20w-50) but the additive package might be lacking; the diesel oil has a lighter viscosity (15w-40) but will likely have a stronger additive package; I think it deals with 'common sense' viewpoint of what is a 'preferred' top off oil when the 'ideal' 20w-50 motorcycle oil might not be available...better to use a strong diesel oil to protect the engine than a thicker car oil with a weaker additive package

 

[BusyLittleShop]

Originally Posted By: SJohnson

BusyLittleShop, do you have a link to the testing done by 540Rat?

https://540ratblog.wordpress.com/2013/06/20/motor-oil-wear-test-ranking/

 

[BigCahuna]

Originally Posted By: kmrcstintn

this might be a bit simplistic... a Harley owner is out on a long trip and discovers he/she is low on oil and didn't pack an extra quart; not everywhere that sells oils will have motorcycle specific oil & might be more likely to carry diesel oil along with car oil; the car oil will have the correct viscosity (20w-50) but the additive package might be lacking; the diesel oil has a lighter viscosity (15w-40) but will likely have a stronger additive package; I think it deals with 'common sense' viewpoint of what is a 'preferred' top off oil when the 'ideal' 20w-50 motorcycle oil might not be available...better to use a strong diesel oil to protect the engine than a thicker car oil with a weaker additive package

You can go into pretty much any auto store and get Valvoline VR-1 20/50 wt automotive racing oil. That oil would take care of any additive concern you have, plus you won't be watering down your 20/50 with 15/40 wt oil. It might even bring up the additive level of Harley oil, and it's cheaper too.,,,

 

[kmrcstintn]

Originally Posted By: BigCahuna

Originally Posted By: kmrcstintn

this might be a bit simplistic... a Harley owner is out on a long trip and discovers he/she is low on oil and didn't pack an extra quart; not everywhere that sells oils will have motorcycle specific oil & might be more likely to carry diesel oil along with car oil; the car oil will have the correct viscosity (20w-50) but the additive package might be lacking; the diesel oil has a lighter viscosity (15w-40) but will likely have a stronger additive package; I think it deals with 'common sense' viewpoint of what is a 'preferred' top off oil when the 'ideal' 20w-50 motorcycle oil might not be available...better to use a strong diesel oil to protect the engine than a thicker car oil with a weaker additive package

You can go into pretty much any auto store and get Valvoline VR-1 20/50 wt automotive racing oil. That oil would take care of any additive concern you have, plus you won't be watering down your 20/50 with 15/40 wt oil. It might even bring up the additive level of Harley oil, and it's cheaper too.,,,

very true...I was thinking more toward pulling into gas station to fillup, checking oil, and finding out yer low; how many gas stations/quick marts/truck stops have motorcycle oil or automotive racing oil on the shelf? diesel oil is much more common in stores that have limited shelf space...

 

[rossn2]

Amsoil does not make a specific 20w-50 Diesel Oil.. They make SAE 20W-50 Synthetic Premium Protection Motor Oil" which can cover gas and diesel applications. as DR stated Diesel oil is only recommended as last resort and get the oil changed out as soon as possible.. And BigC is right on availability in any automotive store. Haven't found any API rated MC oils probably due to costs involved and the MC community a small market. Have run Amsoil, Redline, Valvoline in my HD's. Now, I run Schaffers Supreme 7000 20w-50 in engine and primary and the gear oil in the tranny. It's cheaper than boutique oils and I have a dealer close by so no high mailing costs..

 

[alarmguy]

Originally Posted By: rossn2

Amsoil does not make a specific 20w-50 Diesel Oil.. They make SAE 20W-50 Synthetic Premium Protection Motor Oil" which can cover gas and diesel applications. as DR stated Diesel oil is only recommended as last resort and get the oil changed out as soon as possible.. And BigC is right on availability in any automotive store. Haven't found any API rated MC oils probably due to costs involved and the MC community a small market. Have run Amsoil, Redline, Valvoline in my HD's. Now, I run Schaffers Supreme 7000 20w-50 in engine and primary and the gear oil in the tranny. It's cheaper than boutique oils and I have a dealer close by so no high mailing costs..

Your post is not entirely correct and some people might misread what you wrote. 1. Amsoil 20/50 oil is listed in the "Diesel Oil' section of Amsoils website. True, on the page Asmoil promotes it as a Rated S and C motor oil and I guess that is why you say they do not make a specific 20/50 c rated oil. But that is incorrect. It is a C rated 20/50 oil and also rated with other S ratings. ALL diesel Oils from Rotella, Mobil, Valvoline, Delo also list the automotive S rating as well ... they just market it different ... Here is the page, scroll down ... Amsoil Diesel 2. You are incorrect that Harley lists " Diesel oil is only recommended as last resort" There are no such words in my manual, not even close to those words.. My 2014 Touring Manual says "HD360 20w50 is the preferred oil.." it goes on to say "if 360 is not available, add oil certified for diesel engines" "CH4, CI4 and CJ4" "preferred viscosities, in descending order are: 20w50, 15w40, and 10w40" it then does say "At the first opportunity, see an authorized dealer to change back to 100% Harley-Davidson oil." Some might see that as a "last resort" I dont and if Harley wanted to warn you they would have used those words, clearly they just think their oil is best. Which is a Citgo diesel type oil formulated for HD and why the C rating ... in fact Citgo makes a 20/50 diesel oil, its on their website, but darn, you cant buy it anywhere that I can find, then there is a semi syn diesel in Citgos Mystik brand you can buy anywhere in the 15/50 weight.

 

[BigCahuna]

And if it's 72 degrees out, you find yourself 1 qt low on oil and you go into the local Quickee Mart for a qt of "recommended " oil , and can only find Rotella T 15/40 wt oil. Probably the easiest wt to find , is not the correct oil to use, per the moco.,,

 

[pwr2tow]

Originally Posted By: BigCahuna

And if it's 72 degrees out, you find yourself 1 qt low on oil and you go into the local Quickee Mart for a qt of "recommended " oil , and can only find Rotella T 15/40 wt oil. Probably the easiest wt to find , is not the correct oil to use, per the moco.,,

Wrong. My owners manual clearly states I can use a 15w40 diesel engine oil. Rotella T 15-40 is also JASO rate as stated right on the jug.

 

[pwr2tow]

I use Mystik 15-50 in my HD and have drove in slow Sturgis ralley heat the past two years plus my usual every day day driveing and have zero complaints. Just bought a 5 gail pail for $54.00 with a $25.00 rebate which makes it $29.00 for 20 quarts. Read any HD website or even within this site and you"ll see plenty of people running diesel rated engine oil.

 

[Robenstein]

Originally Posted By: pwr2tow

Originally Posted By: BigCahuna

And if it's 72 degrees out, you find yourself 1 qt low on oil and you go into the local Quickee Mart for a qt of "recommended " oil , and can only find Rotella T 15/40 wt oil. Probably the easiest wt to find , is not the correct oil to use, per the moco.,,

Wrong. My owners manual clearly states I can use a 15w40 diesel engine oil. Rotella T 15-40 is also JASO rate as stated right on the jug.

Last HD manual I saw said to only use a 40 weight in cold temps, like below 40F if I recall.

 

[rossn2]

Quote:

1. Amsoil 20/50 oil is listed in the "Diesel Oil' section of Amsoils website. True, on the page Asmoil promotes it as a Rated S and C motor oil and I guess that is why you say they do not make a specific 20/50 c rated oil. But that is incorrect. It is a C rated 20/50 oil and also rated with other S ratings. ALL diesel Oils from Rotella, Mobil, Valvoline, Delo also list the automotive S rating as well ... they just market it different ... Here is the page, scroll down ... Amsoil Diesel

I know it's listed in the Diesel section and it's not marketed as a specific Diesel Oil like the others.. The 20w-50 may be oil used by bikers prior to the specific Amsoil MC 20w-50 oil

Quote:

You are incorrect that Harley lists " Diesel oil is only recommended as last resort" There are no such words in my manual, not even close to those words.. My 2014 Touring Manual says "HD360 20w50 is the preferred oil.." it goes on to say "if 360 is not available, add oil certified for diesel engines" "CH4, CI4 and CJ4" "preferred viscosities, in descending order are: 20w50, 15w40, and 10w40" it then does say "At the first opportunity, see an authorized dealer to change back to 100% Harley-Davidson oil." Some might see that as a "last resort" I dont and if Harley wanted to warn you they would have used those words, clearly they just think their oil is best. Which is a Citgo diesel type oil formulated for HD and why the C rating ... in fact Citgo makes a 20/50 diesel oil, its on their website, but darn, you cant buy it anywhere that I can find, then there is a semi syn diesel in Citgos Mystik brand you can buy anywhere in the 15/50 weight.

Read between the lines..why would Harley recommend changing oil at First opportunity? In some weird way maybe they think using different oils will cause quick depletion of the add pack??

 

[BigCahuna]

If anything a Diesel oils additive package will bolster up Harley's anemic package.,,

 

[alarmguy]

Originally Posted By: pwr2tow

I use Mystik 15-50 in my HD and have drove in slow Sturgis ralley heat the past two years plus my usual every day day driveing and have zero complaints. Just bought a 5 gail pail for $54.00 with a $25.00 rebate which makes it $29.00 for 20 quarts. Read any HD website or even within this site and you"ll see plenty of people running diesel rated engine oil.

Thanks for the feedback on the Mystik, I have heard of many who run it. Yes, I am aware many run diesel oil which is also SM rated. But forget all that, I the reason I will run diesel is because that is what HD recommends. My bike is under warranty as well, so I will use the oil they recommend and I bet they know more then me! HOWEVER I only want to run 20/50. I have HOT summers here and will not use a lighter oil, that makes the Diesel rated oil harder to find, Mystik is one, Amsoil the other and saw another one or two around. For now, Im happy with the conventional HD360 20/50, actually, there is no reason for me to use anything else, except I like to mess around with different oils, chances are good I will try that Mystik one day but do not think I will when I change the oil in the next month or so, bike is still new and I am happy with the HD 360, I think I will like to get a few more thousand miles on it first, not that it matters but it does to me, then again, anything can happen in the next month! I can get Mystic locally at Oriellys. Im REALLY tempted, we will see, I also found it online a number of places. I like the fact its only a semi, Im not big on synthetics in bikes, I have my reasons, no sense getting into that in here! ha! As far as some remarks in here about the HD oil, to me personally, its a nice robust oil that turns in great UOAs. Im unsure what others do not like about it, except maybe its has the HD label on it. Its got an ok add package with a nice helping of Boron and Moly, the viscosity is also robust, this is no light weight 20/50! $33 a gallon isnt cheap but heck its not bad for an OEM oil, not at all and has been tested over and over. Like I say, ANYTHING can happen before I buy my next oil change, got the filter and can go either way, Mystik or HD 360. One other thing for leaning the 360 way is I am going to send in my current 360 for a UOA and doing another change with the same oil will give me more of a reference as the bike is still breaking in, so either way metals will be down further with the next oil change no matter the oil, if I go Mystik route I will not know how much lower the metals go as it will be a different oil. That is one heck of a price you paid...

 

[kballowe]

Originally Posted By: BigCahuna

And if it's 72 degrees out, you find yourself 1 qt low on oil and you go into the local Quickee Mart for a qt of "recommended " oil , and can only find Rotella T 15/40 wt oil. Probably the easiest wt to find , is not the correct oil to use, per the moco.,,

There are some that are running Rotella 15W-40 exclusively and have not reported any problems. Personally, I wouldn't be one of them. Yes, Rotella is like a cockroach. Everywhere !