engine oil, Is owners manual wrong?
Seasoned HDF Member
Joined: Mar 2009
Posts: 24,730
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From: Snow Hill, NC
I saw that in my manual and also in the Sporty manual but i couldn't make myself put a straight weight oil in anything except my lawnmower...To each their own...I like a20W50 either Syn or Dino...I personally use Syn...Used different brands, HD, Mobil 1 and Amsoil...Now i use 15W50 Mobil 1 from Wally world...I have now become a Amsoild distributor and will probably buy Amsoil next.
Outstanding HDF Member
Joined: Oct 2007
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From: El Cajon Ca.
I have run both 50 and 60 wt oils in the summer. it's fine as long as you are in the heat. I prefer Redline 20/60 though. It holds up in the 100+ heat real well. I think your problems are not related.
Extreme HDF Member
Joined: Sep 2005
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From: Baton Rouge, LA
Since most wear in an engine occurs in the first few seconds of operation when cold, you want the oil flowing as freely as possible. To maximize this you don't want a thick oil, but a thin oil when cold that also protects like a heavy oil when hot. That's why almost every engine mfr. today requires multi-viscosity oils.
Synthetic also lubricates better in the early stages of operation. It adheres to metal surfaces longer than fossil oil and thus provides a coating that protects better during that first few seconds of operation.
The HD manual doesn't say you must to use single-visocity oils in those higher temperatures, but that you can use them if you want as long as the temperature requirements are met. It says that 20w50 is recommended for temps >40°F, which covers most any riding conditions I would encounter in S. LA. Personally, I wouldn't run singe-viscosity oil alone under any circumstances.
BTW, the engine oil you use would have no bearing (pardon the pun) on the longevity of your primary components. It could, however, affect lifter operation if too thick.
Synthetic also lubricates better in the early stages of operation. It adheres to metal surfaces longer than fossil oil and thus provides a coating that protects better during that first few seconds of operation.
The HD manual doesn't say you must to use single-visocity oils in those higher temperatures, but that you can use them if you want as long as the temperature requirements are met. It says that 20w50 is recommended for temps >40°F, which covers most any riding conditions I would encounter in S. LA. Personally, I wouldn't run singe-viscosity oil alone under any circumstances.
BTW, the engine oil you use would have no bearing (pardon the pun) on the longevity of your primary components. It could, however, affect lifter operation if too thick.
Last edited by iclick; Feb 22, 2010 at 10:15 PM.
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Multi weight oil is made for multi-temperature swings...
The manual is correct. Depending on ambient temperature expectation you use what is called for accordingly. I have lived in southern florida for over 35 years now. I watched as straight weight oils have all but disapeared from the shelves, simply because of popularity. Northern vacationers and transplants have become accustomed to using multi weight oils, so that's all they want, and that's what sells. EVERY vehicle manual tells you to select the oil viscosity according to the prevailing ambient temperatures. People who have read and know how to choose oil will never convince those that are used to buying something else.
Multi weight oils change viscosity with temperature swings. The lower the temperature, the lower the viscosity. If the temperature never gets low enough for the oil viscosity to reach the lower weight, then it remains in the higher or thickest state.
Watch the responses to my post if you want to see how people are unwilling to change, even if the advice is written in the manuals. OOPS! You've already seen that haven't you?
The manual is correct. Depending on ambient temperature expectation you use what is called for accordingly. I have lived in southern florida for over 35 years now. I watched as straight weight oils have all but disapeared from the shelves, simply because of popularity. Northern vacationers and transplants have become accustomed to using multi weight oils, so that's all they want, and that's what sells. EVERY vehicle manual tells you to select the oil viscosity according to the prevailing ambient temperatures. People who have read and know how to choose oil will never convince those that are used to buying something else.
Multi weight oils change viscosity with temperature swings. The lower the temperature, the lower the viscosity. If the temperature never gets low enough for the oil viscosity to reach the lower weight, then it remains in the higher or thickest state.
Watch the responses to my post if you want to see how people are unwilling to change, even if the advice is written in the manuals. OOPS! You've already seen that haven't you?
Last edited by CroK; Feb 22, 2010 at 11:06 PM.
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Like I said above, if the temperature does not go low enough for the oil viscosity to change, it will remain at the higher viscosity. Just because the engine is 'cold', meaning not warmed up, doesn't mean the oil is at the lower viscosity allowing it to circulate more readily. If the ambient temperature is a consistent 80° F or above, multi weight oil will remain at it's higher rating (viscosity/weight).
To explain further, multi weight oils have been chemically engineered to change viscosity according to temperature. Straight weight oils change viscosity also, but in a different manner. When multi weight oil gets warm it thickens, gaining in viscosity. When straight weight oils gets warm, it gets thinner losing viscosity. Although we used the two terms (viscosity and weight) interchangebly, they are not the same.
Last edited by CroK; Feb 24, 2010 at 11:30 AM.
Road Warrior
Joined: Mar 2007
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From:
Since most wear in an engine occurs in the first few seconds of operation when cold, you want the oil flowing as freely as possible. To maximize this you don't want a thick oil, but a thin oil when cold that also protects like a heavy oil when hot. That's why almost every engine mfr. today requires multi-viscosity oils.
Synthetic also lubricates better in the early stages of operation. It adheres to metal surfaces longer than fossil oil and thus provides a coating that protects better during that first few seconds of operation.
The HD manual doesn't say you must to use single-visocity oils in those higher temperatures, but that you can use them if you want as long as the temperature requirements are met. It says that 20w50 is recommended for temps >40°F, which covers most any riding conditions I would encounter in S. LA. Personally, I wouldn't run singe-viscosity oil alone under any circumstances.
BTW, the engine oil you use would have no bearing (pardon the pun) on the longevity of your primary components. It could, however, affect lifter operation if too thick.
Synthetic also lubricates better in the early stages of operation. It adheres to metal surfaces longer than fossil oil and thus provides a coating that protects better during that first few seconds of operation.
The HD manual doesn't say you must to use single-visocity oils in those higher temperatures, but that you can use them if you want as long as the temperature requirements are met. It says that 20w50 is recommended for temps >40°F, which covers most any riding conditions I would encounter in S. LA. Personally, I wouldn't run singe-viscosity oil alone under any circumstances.
BTW, the engine oil you use would have no bearing (pardon the pun) on the longevity of your primary components. It could, however, affect lifter operation if too thick.
+1 on this response. Haven't you noticed later model cars using 5w-30? Tolerances are tighter in everything now. I always ran straight 60 in Shovels and Ironheads. The tolerances on the evos and twin cams are tighter and getting oil in those tight spots requires the multi viscosity oil. Yup, most wear occurs at startup not after it's warmed up.
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Joined: Sep 2005
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From: Baton Rouge, LA
I agree with what you've said here, but I think you misunderstood the meaning of my statement, likely because of the unclear way I worded it and my failure to quote the message I was replying to. I was responding to a comment by the OP that he had a bearing fail in his primary, and "primary components" was referring to my feeling that engine oil could not affect a bearing in the primary.
Last edited by iclick; Feb 23, 2010 at 10:41 AM.
Outstanding HDF Member
Joined: Jan 2008
Posts: 3,328
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From: Pacific Northwest
Here goes: Like CroK says, multi-viscosity oils remain at the lowest viscosity until engine temperature causes a chemical reaction raising the viscosity. Many straight weight oils lack the additives and detergents of the newer multi-vis oils. I don't know about HD oils and HD has always kept info on them as "classified information" and very top secret. Just try asking a question regarding Primary oil; no one seems to know (or will tell you) exactly what it is.
If you and your bike never go anywhere that the ambient temp drops below the recommended low for straight weight oil then go for the straight weight; otherwise a multi is the prudent choice.
If you and your bike never go anywhere that the ambient temp drops below the recommended low for straight weight oil then go for the straight weight; otherwise a multi is the prudent choice.