I see this debate going on in every motorcycle forum continuously, so I am going to weigh in with my thoughts. Opinions on oil are like a**holes, everybody has one. I have owned an maintained 60-70 motorcycles of all varieties and have never had one oil related failure These are the guidelines I go by.
Auto Oil or Motorcycle Specific Oil
These debates get HEATED but I never pay much mind. The argument for motorcycle specific oils is that motorcycle oils are shared between the motor and the transmission and clutch components. Because of this they face more abuse than an auto oil would inside of a car. The faces of the transmission gears mashing together cause significant wear to your oil, which is why it is best recommended that motorcycle oils are changed on a more regular basis than a car. Most vocalists for motorcycle specific oils state that you should use them because they have additives to keep your clutch plates from slipping and wearing out faster.
In my book (remember, everyone has an opinion) oil is oil. A good quality auto oil is just as suitable for a motorcycle and gearbox as is a motorcycle specific oil. Auto oils also cost 1/3 the price and are available everywhere. I do not want to be tied to a dealer to get my oil. Occasionally I need to change oil while out on the road. If you use a common auto oil you can stop at any auto store, Walmart, or gas station and pick up a few quarts.
As for clutch condition. I have always used auto oils in every one of my bikes. I ride my bikes hard and frequently, and over all the years of riding on all sorts of different machines, I’ve only ever replaced clutch plates in one of my street bikes. Clutches are built to last and as long as your oil is kept clean, they will.
Oil Weight and Viscosity
Thick or thin? Warm blooded or cold blooded? It doesn’t make a whole lot of difference unless you are riding in extreme conditions (very hot or very cold temperatures). Just like a car any typical 10w-40 weight oil is going to work great in most applications. Some prefer to run a 20w-50, but there really isn’t a huge difference. Again, I prefer to use something real common so I can find it anywhere I go.
Synthetic or Fossil Oil
This gets a lot of heat in the forums too. Quality synthetic oils have only been available for 10-12 years. Engines built prior to that time period were not designed to use synthetic oils and should therefor use fossil oils. A new bike with low miles will benefit in the long run by using a synthetic oil, it has been proven that they really do protect better.
Consistency
This is something I feel very strongly about. Pick an oil and stick with it. I don’t like mixing and matching oils, I much prefer to pick one type of oil that is commonly found in auto stores and stay the course. I do this with all my vehicles. I have no science to back up any claim that switching oil brands all the time is hurtful to your engine (and I doubt that it is). But there is something comforting about knowing the history of a bike, knowing that it is consistently maintained, and being able to recognize the condition of the oil by looking at the dipstick.
The Important Part
The important part of oil related motorcycle maintenance is not so much what oil you use, but how often you change it. Many motorcycles have drastically different oil capacities and run at much different RPM’s. Those two factors are what contribute the most to the life of the oil in your bike. A bike with a large oil capacity that runs at relatively low RPM (like a large cruiser or mid sized twin) will circulate the oil slower and cause less wear. A high strung motorcycle (performance or sport oriented) will circulate the oil much faster and wear it out in about half the time. Most of my street machines get their oil changed every 2,000 miles.
What to Watch Out For
- Don’t run synthetic oil in an older motorcycle that has not been using it. Synthetic oils are more thin than fossil oils and can seep right though old gaskets. If you bike has been running on dino oil, keep it that way.
- Cheap oils. OK, auto oils may be inexpensive, but don’t get the CHEAP stuff. Buy a major brand oil (mobil, pennzoil, castrol, etc) at a typical price point ($3-4 a quart). If you’re buying some garbage oil like “Master Cruiser†for $1.39 at the dollar store, you are going to be sorry. Cheap oils are just that, cheap. They are the remaining sludge in the tank, they are often recycled, and if you look up their ratings they are often not suitable for vehicles made after 1950! Just use common sense and you’ll be fine.
- Detergents. There aren’t many oils that use detergents anymore, this can probably be lumped into the ‘cheap oil’ category. Back in the day they used to add detergents to oils to ‘clean’ the motors. This is no longer common practice as oils and motors have come a LONG way over the last 50 years. Do NOT put an oil with detergents into your wet clutch motorcycle. The detergents will make your clutch slip terribly and you’ll need to flush the system several times with fresh oil, and maybe even remove the clutch plates to clean them by hand. Consider yourself warned. If there are detergents in an oil it will say it on the bottle, no common modern oils have detergents.
- Keep it topped up. After a long day of riding, or riding in some extensive heat, I always check the motor oil level. In fact, I check my oil nearly every time I stop for gas. It’s cheap insurance. This habit was developed over the years of riding old motorcycles that weren’t in optimal operation conditions and burned and leaked oil, but it is good practice for any rider on any bike. Always better safe than sorry.
Is There More to the Oil Story?
For some people there is more to the oil story. For me there is not.
What Oil Do I Use in My Motorcycles
If you’re curious exactly what oils I run, here it is.
- For the past 6 years all of my street going and 4 stroke off-road motorcycles have received standard Pennzoil 10w-40. I have found it to perform beautifully, it’s available everywhere, it’s priced right, and it’s easily identifiable in a bright yellow container.
- My 2 stroke off road dirtbikes get any Dextron III ATF in the transmission and Klotz R-50 premixed in the gas.
I would recommend these choices to anyone with nearly any type of bike. If I had a brand new bike (or near new bike) I might run a synthetic, maybe. Oil change frequency is much more important to me than type of oil. Pick an oil, stick with it, change it regularly, ride happy.
