[Dupo]

Found it -- its from the honda forum, but applies to all.

Oilology


This post was created to help answer some of the common questions about oil that so often passes through this forum.

Keep in mind that all modern API approved oils are high quality oils. Honda recommends an API service classification of SG or higher for our Shadows.

Q. Can I use automotive oils in my Shadow?

A. Yes, anytime you use automotive oil it is referred to as ‘Non motorcycle specific oils’. If you’re going to use these oils just keep a few things in mind.
(1)Be sure you buy an API certified oil.
(2)Check the bottom half of the API seal, if it has the words ‘Energy Conserving’ then its probably better to pass on that one.
(3)If you do use an automotive oil you might want to reduce the mileage between oil change intervals.

Q. Can I use a heavy-duty truck oil like Mobil Delvac or Shell Rotella-T?

A. Yes, these oils are becoming quite popular among motorcyclist. The additive packages used in these oils more closely match the additive packages used in or claimed to be in the motorcycle specific oils. The truck oils are API certified unlike many of the motorcycle specific oils that only claim to meet a certain API certification. The truck oils have API certification codes for both diesel and gasoline engines.
The Chevron Delo oil is the only one that I might caution someone about using because it has a pretty high level of Moly in it and it could lead to clutch slippage
You can also go the same mileage between oil changes that you would with a motorcycle specific oil. These oils are designed for higher mileage applications.


Q. Can I use Synthetic oil in my bike?

A. Yes, there isn’t anything about synthetic oil that would make it not useable in our Shadows. Now that’s not to say that synthetic oil will work in everyone’s bike because some engines and some riding conditions just don’t match up well with certain types of oils. That also goes for any oil, synthetic or crude.

Also synthetic oil is no different than any other oil in that it shouldn't be an 'Energy Conserving' type oil. So be sure you look at the API service seal on the bottle to make Sure the words 'Energy Conserving' are not listed in the bottom half of the circle.

Q. How many miles should I have on my bike before I can change to synthetic oil?

A. This question always gets some wild answers. If you wait until the first 600 mile service then you should be fine. The statements of having to go thousands of miles before you can switch to synthetic oil are nothing more than myths.

Q. Can an engine have too many miles on it to change to synthetic oil?

A. The oil manufacturing companies say ‘No’ but I disagree with their claim. There are countless testimonies of people developing oil leaks and rattles after changing to synthetic oil in late life high mileage engines. The rattles are not nearly as common as the leaks. The problem is that there isn’t a set amount of mileage or time that marks the point of being to many, or to long. What most people would call low mileage I would say would be fine, 20,000 miles or so. As for age, I would call any engine that is over ten years old an older engine and for sure any that was manufactured pre 1990. The reason I say pre 1990 is because the crude oils of that time could have well plated the inside of the engine with more varnish than the later dated oils.
You might very well be able to switch to synthetic oil in a much older vehicle with a lot more miles on it than 20,000 and not have a problem at all. But it gets to be like the rolling of dice: sometimes you win, sometimes you lose. If you have an older bike that has a fair amount of miles on it and it’s running good, then I would say, ‘Let the sleeping dog lie’.

Q. What’s the best viscosity range of oil to use in my bike?

A. Honda recommends using 10W-40 oil for what is considered ‘Normal riding conditions’. That does not mean you have to use that, nor does it mean that a 10W-40 oil is the best for your riding conditions. It’s quite possible that you could choose an oil with a more dedicated viscosity range. The recommended 10w-40 oil is the most universal oil or the one oil that covers the widest temperature spread between different climates. A good crescent wrench will fit the 13mm bolt, but not as well as a good 13mm six point socket will. If you’re not going to be starting your bike (cold starts) in temperatures below 20 degrees (f) then you could move up to a 15W-40 oil or even a 20W-40. The same thing applies to the high number listed for the oils viscosity range, except on the other end of the temperature range. If you don’t do a lot of extreme hard riding in extreme heat like above 110 degrees (f) then you probably don’t need an oil with the high number above 40. What about those that do ride in the extreme heat? They would be more concerned about the high viscosity number. They would do better using an oil like, 20W-50 or even a 15W-50.

Q. What is a good mileage to go between oil changes?

A. The Honda owner’s manual for my ‘97 1100 Spirit states 8,000 miles. There seems to be two understandings of this recommendation.
(1)Honda recommends 8,000 miles, so that is what you are supposed to do. It’s a good thing.
(2)The recommended 8,000 miles is a Maximum amount of miles to leave the oil in the engine.

Number 2 would be the more correct answer. Think about it like this. If your bike is still under warranty and you go beyond the recommended 8,000 miles before you change the oil it can jeopardize your warranty. Some live with the belief that whatever the owner’s manual states is an absolute! In a way it is, if you think of it as the absolute Max number of miles and beyond that can cause damage to your engine. That tells me that an oil that is left in our Shadow engine’s for 8,000 miles has out lived its usefulness.
Here is what I recommend for the mileage between oil changes.
Automotive oils = 2,000 to not over 2,500 miles.
Heavy-Duty truck oils = 3,000 to 3,500 miles.
Motorcycle Specific oils = 3,000 to 3,500 miles
All Synthetic oils = around 5,000 miles.

The above listed mileage’s does not mean you should let used oil rest in the bikes engine during long periods of storage.

Q. I bought some extra oil on sale, how long can I store it?

A. The actual oil doesn’t really ever-go bad but the additives can. I sent out an email to the Shell Oil Company with this question, they informed me that an unopened bottle of oil has a shelf life of five years. They went on to say that it is possible that oils that old may still be usable, but it should be tested first.

Q. Are there any oils that are known to cause problems with our bikes other than 'Could cause problems'?

A. I don't know if there is any one oil that would be a problem in Every motorcycle that you put it in. There is one type of oil that I wouldn't put in my motorcycle on a dare.
Some oil companies now have a line of oils that are designed for older higher mileage engines. These oils have additives in them to help seal oil leaks and to help better control oil flow. These additives will at lest cause Some wet clutches to slip. I have seen an older Virago that had a six month old clutch torn down due to the owner changing to one of the 'High Mileage Engine oils'. Another thing about that Virago was that changing back to his normal oil didn't help the clutch. To fix the bike the mechanic had to remove the clutch plates, soak them in kerosene, dry them, then he used a fine sand paper and buffed the surface of all the plates and re-installed them.

Q. What’s the correct way to check the oil in my Shadow?

A. From the Honda OEM service manual.

“Start the engine and let it run for a few minutes.
Stop the engine, remove the dipstick and wipe the oil from the dipstick with a clean cloth.
Two to three minutes after stopping the engine; with the motorcycle in an upright position, insert the dipstick into the stick hole without screwing it in”

The important points to remember is that the motorcycle Must Be on level ground and in an upright position not resting on its side-stand.
Next, to properly read the oil level on the dipstick you Must Not screw it into the engine, the dipstick is to only rest on top of the dipstick hole.

Q. How do I correctly read the oil level marks on the dipstick?

A. It’s really no different than the reading the dipstick in a car.
The Honda service manual states that when the oil is Near or Below the lower mark that you are to remove the filler cap and fill to the upper mark. That means that if the oil is somewhere reasonably between the upper and lower marks on the dipstick then the oil is at a safe operating level. That leaves the upper mark on the dipstick as a max fill line, still safe but Max.
Caution! Do Not over fill the crankcase with oil, doing so can damage the engine seals.