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Can I Put Oil for a Car into my Motorcycle?

Mary McMahon
Updated May 23, 2024
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Many motorcycle drivers are given conflicting recommendations about what type of oil to use in their vehicles. Numerous motorcycle manufacturers heavily promote the use of specially formulated motorcycle oils, claiming that these are better for the life of the motorcycle and will not wear down as quickly. In fact, it is perfectly safe to use oil formulated for automobiles in motorcycles, as long as it is of an appropriate viscosity and the motorcycle is kept well maintained, as all motor vehicles should be.

In most cases, it is recommended that motorcycle drivers use synthetic oils in their vehicles. Synthetic is more expensive than natural oil, but will stand up to wear and tear better, and tends to keep desired properties longer. Most companies are making affordable synthetic oils available and it is well worth the minimal extra investment to be assured longer performance. Synthetic all purpose oil is still less costly than that designed specifically for motorcycles.

All oil provides a rating which indicates the viscosity. The lower the rating, the lighter the oil is, meaning that it flows very easily. This is not an issue at low temperatures, but as the engine heats up, it will rapidly begin to degrade, and get very hot. As a result, drivers want one with high viscosity to ensure smooth running of the engine at high temperatures. Many come with a combined rating such as 20W-50, indicating that at low temperatures the oil flows smoothly and as the engine heats, it retains its viscosity. Single grade is available, but multigrade is recommended.

The claim made by many manufacturers of specially formulated motorcycle oil is that which is designed for cars may actually damage the engine of a motorcycle. This is simply not true. While some designed for automotive use is not optimal in motorcycles, most oil is easily interchangeable, although motorcycles are more demanding than cars are. Motorcycles still operate along the same internal combustion principles as cars do, after all.

In scientific testing, it has been determined that motorcycles will break down oil more quickly than cars, with the results being the same for both types. Oil breaks down as repeated circulation shortens the polymers in it, causing the viscosity to be lowered. In addition, increased oxidation and repeatedly running too hot will cause it to break down and become less effective. Testing also determined that synthetic oils are not as subject to break down as natural ones, and are therefore a better choice for drivers.

WikiMotors is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Mary McMahon
By Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a WikiMotors researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Discussion Comments

By anon1004961 — On May 22, 2021

Big no. Motor cehicle oils usually has more friction modifiers than motorcycle oils, and since a motorcycle's engine oil serves also as the transmission oils. Motorcycles usually operate with a wet clutch and deals with clutch friction inside the engine while maintaining proper lubrication for the engine side.

Hence motorcycle oils have a JASO rating usually JASO MA/MA2 for wet clutch engine and JASO MB for dry clutch engines, which is most of the time for motor vehicles doesn't have on its specifications that is indicated to be an alternative for motorcycle oil. The same goes to motorcycle oil use for wet clutch is not recommended for motor vehicle engines which required specific friction modifiers.

By anon967940 — On Aug 30, 2014

So can all the service techs like Kilroy just knock it off with the "car oil is bad" crap? For those of us who actually ride them, and not just service them, car oil works just fine. Get over it, man.

By anon955672 — On Jun 09, 2014

I need advice from senior bikers. I am currently riding a Kawasaki Z800. so Last week, I changed the engine oil in my bike. I am using top 1 high performance 10w40 made in the USA. After the change, I have had no problems. I need advice please.

By anon348875 — On Sep 21, 2013

I work in a motor factory and deal with a lot of oils. I use 10w40 semi in my XJR 1300. Oil is oil and if you have a wet clutch, then it needs oil. Don't worry about the dealer's recommendation. Car oil will do the trick. I've been using 10w40 car oil in my bikes for the last seven years and it's never caused me any problems.

By anon333419 — On May 05, 2013

I'm thinking of using Catrol GTX 10w40 car oil on my Ducati 900ss which is air-cooled and has a dry clutch. Any advice?

By anon326456 — On Mar 21, 2013

I am 65 years old and have ridden Harleys, Suzukis, and Yamahas my whole life. I've always used car oils and never had an engine, transmission, or clutch failure. The last few years I have used the more expensive synthetic car oils in my motorcycle. So far, so good!!

By anon283822 — On Aug 06, 2012

My anonymous 2 cents worth: To the fellow who asked "wet clutches, what's next the (boogey)man?" Umm, better read up. Motorcycle clutches run wet, my friend. I know there are plenty more, but only one dry clutch bike in recent history comes to mind and that was that special edition Suzuki GSX750R in the late 80's.

Secondly, I have a V4 1200 cruiser with a hydraulic clutch (no adjustment) and the bike always hooks up like a freight train, until that is one time I dumped 4qts of automotive oil in her and immediately the bike would rev well over my road speed and I thought, "Uh-oh! Something's not right." I flushed the engine, got some 'Zuke oil and after a couple hundred miles and two or three more change outs, it hooks back up again. Now you tell me: car oils with friction reducers in a wet clutch bike (adjustment and knowledge of clutch use aside) that I'm imagining things? Hardly. They don't mix.

And I will go on record as saying that anyone who can't get their head out of the box and realize that just because it looks like oil, smells like oil and may even taste like oil, doesn't mean that at the molecular level "oil is oil" and you're uninformed if you think that.

By anon271083 — On May 24, 2012

I had put over 50,000km on both my 1978 Honda CX500 and 1996 Yamaha YZF600. I always used regular car oils that satisfy oil requirements on the service manual: SAE, API with non-energy conserving ones. I never got engine or clutch problems.

By anon249065 — On Feb 19, 2012

Here it is. I have used car oils, almost all brands, with no problems, and put 148,000 miles on 600cc v twin. Yes, the engine wore some, but but this engine had an oil burning problem when getting high in mileage. Who to trust? Read your manual, and use what oil they say to use.

Don't use energy conserving oil. Now put in regular oil and put tons of miles on and enjoy your motorcycle, and keep the money in your pocket.

By anon229076 — On Nov 11, 2011

I have a 03 Honda VTX1800C with 80,000 miles, bought new in 2005. The only oil I use is Mobil 1 fully synthetic auto oil 15W-50. It runs like the day I bought it, never an engine or clutch problem. Oh, I change the oil every 8,000 miles. Just my experience.

By anon222134 — On Oct 14, 2011

OK, the engine in a 4T car may be similar to the engine of a 4T motorcycle. It's all about the design and level of tune. But both need different oils because the requirements are different. A car has a multigrade engine and an EP transmission oil [gearbox] oil. 99 percent of bikes have one oil to do the job, be it a modern synthetic multigrade oil or single grade. Vehicle engine oil does not have to put up with the crushing and shearing of its Viscosity Improvers [VIs] in a car engine that it would in the bike's engine/transmission. Therefore, a motorcycle oil is designed to cover this requirement, by being designed to run consistently well without the need for VIs. Therefore simply, don't put a modern car oil in your modern bike, or you will shorten the life of the gearbox. Use a synthetic bike oil, designed for the purpose, and change at service intervals. It's cheaper in the end.

By anon214035 — On Sep 13, 2011

i agree that you can use car oil, using a semi synthetic can give you an extra 2 bhp.

By anon205846 — On Aug 14, 2011

I'm aaron from singapore a newbie with DR200SE (Suzuki Enduro bike). After reading all the "expert" comments, I am convinced that motor oil for cars can be used for motorcycles so long as there is no friction modifiers or energy conserving elements in the motor oil. Thank you guys. I am starting with Shell Helix 5w-40 synthetic.

By anon199065 — On Jul 21, 2011

I myself once used the remaining oil after change oil of my car and pour into my motorbike. The clutch is very much terrible and after one week I did realized that it was the oil! I had to change to normal oil for my bike.

By anon190309 — On Jun 25, 2011

So called "experts" can claim oil is oil and therefore one can use car oil in a motorcycle. Yes the clutch is a wet clutch therefore needs oil. However, car oil has a tendency to foam at high revs (like a motorcycle v a car) as well as one undisclosed fact. Bikes are not ridden as much as cars are driven. Car oil can and will crystalize on a clutch necesstating a costly repair when the bike won't shift. Recommendation: bike oil in a bike and car oil in a car.

By anon183231 — On Jun 04, 2011

I find it really funny that people think motorcycles and cars are so different, when in fact they are all 4-stroke transverse compression engines. Yes, it is a wet clutch and the oil is shared with the transmission, but guess what? A wet clutch wants oil!

I can't believe people are willing to trust oil companies when science clearly shows there is no difference. Don't let them stir fear so that you are willing to give them more money for peace of mind! Its a scare tactic and nobody should support that kind of crap.

Good oil is good oil. A wet clutch cannot slip because of oil as long as it's not EC. It wants to be wet, you know, with oil.

By anon170486 — On Apr 26, 2011

I would think oil, any kind of oil, would be the last thing to cause a valve to go even on a Kawasaki 500. Use the proper weight oil that is not energy saving. I can't believe motorcycle engines are that fussy, weak clutches excepted. Of course I am new at this, 47 years doing my own work on motorcycles.

By anon164584 — On Apr 01, 2011

I ran mobile 1 15-50 synthetic through my Ninja 500 after reading an article ( in a motorcycle magazine no less) on how this oil outperformed motorcycle oil in a bike.

Well, 75 miles later my bike blew a valve. Everyone knows Kawasaki Ninja 500 engines are damn strong and mine only has 15,000 on it. sometimes you have to leave well enough alone. car oil in a car. bike oil in a bike.

By anon156827 — On Feb 28, 2011

I've read the posts below, as well as the original article, and I think I can bring something different to the table, as I can give you the perspective of a lubricant manufacturer, which is what I am.

Regular car engine oils are not designed, formulated nor tested to work properly on motorcycle's wet clutches. Motorcycle oils are. However, that doesn't mean that a certain type of car oil cannot do the job.

Old mineral formulas might be up to the task, but I'd suggest you stick to the user's manual first. About synthetic oils being suitable for motorcycles, sure! As long as they are meant for motorcycles, you can use them.

Oh, and the old saying: 'if racing bikes use it, then it's good for your scooter' couldn't be more misleading. Racing bikes change the oil after every race, which isn't the case with your scooter. Also, a scooter is constantly starting / stopping, while a racing bike starts just once every race (well, sort of). There, I hope it helped.

By anon145119 — On Jan 22, 2011

I have run into clutch slippage problems with regular Mobil 1 (not the motorcycle 4T Mobil).

It will be more noticeable in bikes that are driven hard or have modified engines.

Mobil 1 slippage also shows up on the

dynamometer. Slippage usually shows up in the higher gears and on the high performance bikes.

The "A" riders that I do motors for spot it right away, the "C" riders either don't know it's slipping or aren't getting on it enough to make it slip.

By anon140495 — On Jan 07, 2011

I always use car oil in my xj 600 and not even the best bit of this, bit of that. It has 80,0o0 on the clock and on the original clutch and it doesn't miss a beat or slip at all.

You have all obviously got more money than knowledge and use daz washing powder because it says it's better than the supermarket's own. Don't believe what the money grabbers say. You pay for the label.

By anon136785 — On Dec 24, 2010

Great article you have going. I'm still new to biking, some eight months into it after a lapse of 20 years. After reading all your comments, Shell Rotella it is. Thanks guys.

By anon119224 — On Oct 17, 2010

I'm surprised that so many people say that they have used car oil in their bikes for long periods with no problems. I tried quality car oil in my CG125 briefly. I immediately got clutch slip. Yes, the clutch was adjusted properly!

I straight away flushed my engine out and refilled with a bike specific oil. In my mind, I would rather pay a couple of pounds more for an oil that I know to be safe, rather than penny pinch and potentially ruin my clutch. When I move up to a larger bike, with a more powerful engine and more expensive clutch, I certainly won't be trying car oil.

By anon115252 — On Oct 01, 2010

LOL @ Post 26. Obvious Yamaha tech is obvious. It's either that, or you're sold on the hype. Any non-friction-modified oil of the proper viscosity will work in your motorcycle.

But if it makes you feel good to drop $12/qt of oil, go to town bud.

By anon111272 — On Sep 15, 2010

I ran 15W40 castrol GTX in my 1995 XV1100 for 15 years. That's right, ordinary mid-range motor oil, not even synthetic. Bought a new set of clutch plates at 85,000km because I figured it was time, but never installed them. Sold the bike with 150,000km on it this year to upgrade to an M109 boulevard. If I had anywhere to store it, I would have kept it. No clutch slip, no excessive engine wear, no bearing failures - nothing unusual. There's a lot of voodoo and superstition surrounding motorcycle oils. Special motorcycle oils are really just a BS marketing exercise.

By anon110839 — On Sep 13, 2010

I've run full-synthetic oil in my 2003 VTX1800C since it was brand-new and have never had a problem with clutch slippage. I've run full-synthetic oil in my wife's 2007 FZ6 since it was no, with zero issues. I am currently running conventional Walmart auto oil (10w40) in my used CBR600F3 - with 76,000 miles on the clock - in an effort to "flush" the engine before switching to the same Shell Rotella T6 I use in my VTX.

I've worked as a dealer mechanic and currently as a "shade tree" wrench and would advise anyone that it's perfectly acceptable to run auto oils in their bikes, provided they're not labeled "energy conserving." As far as I know, a 5w40, 10w40 or 20w50 oil will never be labeled EC. No motorcycle specific oil will ever be labeled EC. And while we're talkin' oil, 20w50 is a waste in a water-cooled engine. As far as oil filters, I've never put an OEM filter on my bikes. I've used Motorcraft oil filters, AC Delco oil filters, Purolator oil filters and on occasion, Walmart SuperTech oil filters (which are made by the same company that makes Bosch oil filters), with zero problems or complaints. Don't fall for the marketing bull - put out by the companies that are trying to get you to spend money on their products. Listen to the guys doing the riding and the wrenching!

By anon110207 — On Sep 11, 2010

i have a honda cb500 2003 with 155000miles and use castrol high mileage,its still on original clutch plates, bike still singing.irish courier

By anon103492 — On Aug 12, 2010

It's OK to use car oil. I have a bike with a wet clutch if it is not an "Energy Conserving" oil. On the back of the oil bottle look for the round stamp with the classification numbers. If it does not say energy conserving, you are good to go.

E edgy conserving oils contain friction modifiers that can damage a wet clutch, so make sure you check the bottle before you put it in your bike. You'll find that most *w-40 oils aren't energy conserving, and are perfectly safe to use.

Oils branded "High Mileage" are usually not energy conserving. Oils made specifically for motorcycles carry the classification JASO-MA on the back. All this means is that the oil is safe for a wet clutch. Here's a tip: Shell Rotella Synthetic T 6 has every classification you can think of, including JASO-MA, and is an excellent oil for motors with wet clutches.

It says diesel oil on the bottle, but that's only because it's 5w-40, which is what most diesel and heavy equip mfrs. I recommend in their engines. It's 20 bucks a gallon at walmart.

By anon102092 — On Aug 06, 2010

I've been reading all of these post. and I'm going to blow all of your minds!! i have a 2009 fz6r yamaha 600, well, this bike has 76 miles on it. I use 20-50 castrol car engine oil, and on top of that i put six ounce of prolong AFMT (anti friction metal treatment) in the engine of everything i have ever had.

I can lock up the front brake on any of my motorcycles and smoke the back tire in the road! No clutch slipping there! This is one of the best anti friction products in the world. it is amazing to use.

By anon101049 — On Aug 01, 2010

I'm going to play it safe. I ride a Nighthawk 750. Sure my Honda four stroke synthetic is $9 a liter/quart and my bike holds 3.1 quarts, but it buys me the peace of mind that I'm not causing any problems in the near or distant future.

After all, most problems I've heard so far are clutch slippage due to vehicle blended oils. My bike has a wet clutch and an air cooled I-4,so yeah, I'm going to play it safe. A motorcycle is a motorcycle, and a vehicle is a vehicle.

By anon92215 — On Jun 26, 2010

Sold on Synthetic oil, but have Honda Valk that runs good on Honda dino oil, and a KAW 750 Vulcan that has clutch slippage big time with cheap dino oil, then changed back to KAW dino oil and the slippage stopped.

By anon86680 — On May 26, 2010

Important! Take another look at post 10 below. Most auto oils now have lower zinc and phosphorus (high pressure)additives in their oils. This was done to increase auto catalytic converter life. Not a biggie for water cooled stuff (cooler running) but insufficient for air cooled engines (hot).

A hot running, air-cooled engine will tend to prematurely wear cam lobes if a medium quality auto oil is used. Make sure you use a high quality racing oil if you use auto oil. Check some racing oil websites and find which brands still have an adequate ZDP (zinc diophosphate) high pressure additive package. Bottom line is auto oil blends are not what they used to be. High end Castrol and Rotella still have adequate ZDP but some of your common synthetics do not. All "motorcycle" blends have a much greater percentage of high pressure additives in their oil for this reason.

By anon86367 — On May 24, 2010

So a motorscooter should run fine on car oil, even with frictionless energy conserving oil? after all, they have the clutch far and dry away from the engine (various types).

By anon82931 — On May 08, 2010

Thousands of miles ridden on motorcycles w/wet clutches and "car" oil demonstrate you are wasting money to buy motorcycle specific oil. As long as the "car" oil is of a thicker viscosity (10-40 and higher) and does not contain friction reducers (read the container).

By anon82660 — On May 06, 2010

So for a Honda Shadow 1989 with 22,000 miles will it be OK to use a 10w30 or 10w40 car oil??

Its my first bike and don't know what to use or to put in it. I will take in consideration any ideas.

By anon81822 — On May 03, 2010

"Motorcycles still operate along the same internal combustion principles as cars do, after all."

Well, sort of. Car engines are totally separate from the clutch and transmission assembly. Motorcycle engines generally have the transmission and clutch soaking in the same engine oil -- a pretty significant difference.

Car engines generally redline at 5500 or 6000 RPM. My bike redlines at 14,000 RPM.

Car engines generally run cooler - maybe 190 to 210 degrees. Most bikes I've had will run at 230 on a hot day.

So if you really need to save five or ten bucks on your oil change go ahead with the car oil. Or buy yourself a little peace of mind and get some Yamalube.

By anon81814 — On May 03, 2010

his is really cool. I ride a custom V-Twin with a BDL open primary. That means I have a dry clutch which will not be affected by the oil that has been giving the wet clutch crowd a problem.

I am totally ticked at the motorcycle companies for running the crap on us bikers, just to fatten their wallets.

I used to be a big dummy who believed everything I was told without checking the facts myself. There are websites that do tests on oils in a controlled environment and confirms that we have been getting burned for a long time by the motorcycle companies. I hate harley. The bike is cool, but the company blows!

By anon81620 — On May 02, 2010

i used to use motul in my track bikes, switched to rotella t6 for the last two race seasons with no clutch problems. both have slippery clutches. my new cbr1000rr is getting the same oil change in 50 miles (first oil change).

By anon77714 — On Apr 15, 2010

Some automobile oils have friction modifiers; therefore, we must be careful not to use any oil on our motorcycles that has friction modifiers.

This has been a big problem with the Honda Shadow when using energy conserving oil or friction modifiers on the oil, the clutch tends to slip. Mobil 1 synthetic for bikes is OK to use on any motorcycle.

Just remember, when using car oil on bikes, don't use oils with the label energy conserving or friction modifiers made. Shell Rotella in the dark blue container is another good inexpensive quality synthetic oil that you can use. Amsoil is great too, but a bit costly.

By anon77180 — On Apr 13, 2010

I have just put 10-40 semi synthetic Comma oil in a 96 blade with 11k genuine miles. The clutch has started to slip.

I never knew anything about this problem before. Is it a coincidence?

By anon74569 — On Apr 02, 2010

I have had three gsxr1000's and run them all on Castrol RS car oil(0w-40 in winter) and 10w60 in summer. I have never had clutch slip and all three bikes were ridden all year round and all three were taken to their 186 mph limits without a trouble.

RS is difficult to get hold of now so will use Castrol Edge instead.

By anon74079 — On Mar 30, 2010

Kilroy, if you're not supposed to use full synthetics in motorcycles why does Amsoil, Motul and Mobil 1, to name a few, all make a fully synthetic, motorcycle specific oil?

By anon72729 — On Mar 24, 2010

I may as well post my $.02 on the slipping clutch.

I have a 1983 Honda Nighthawk CB650SC with close to 70,000 miles on it. I have used Mobile One synth for Motorcycles for years and years.

I believe that the clutch issues may be from newer oil blends with "friction reduction" additives. I have a buddy who put some (don't know the brand) new oil with the friction modifiers in his Nighthawk, and had clutch slipping issues almost at once. (within 100 miles). We ended up flushing the oil out, and this helped the clutch, but it still slipped some, so we had to replace the clutch plates.

I am not saying this will happen to anyone, and I am sure that most oil will be fine in the motorcycle. But it is not like we are talking about a huge amount of money. Most riders will not be changing oil more than a couple of times a year at most anyhow.

If the cost between car oil and motorcycle oil is a major factor then you probably have other problems to worry about anyhow.

By anon70746 — On Mar 16, 2010

Kilroy: you may have 15 years experience in service work on bikes, but you must get all the bikes that have the "odd man out" problems, because I have been riding and racing for years, and nobody I know on the circuit has ever had a clutch slip using automotive oil.

Most of the teams and most of the MC clubs in my area also use automotive. Specifically Shell Rotella T. If it's good enough for the extreme abuse a race engine takes, then it's certainly good for street use. I think you want to be "right" about oil choice. If you can show me a clutch burned out from auto oil, I will show you someone that A) can't use their clutch properly, or B) clutch was crappy, or C) clutch wasn't adjusted properly to begin with.

By anon60491 — On Jan 14, 2010

I ride a 2009 honda CBR1000 and would like to use fully synthetic oil during my next service, but after reading your posts on the web site I am completely confused. The bottom line is Castrol has a fully synthetic oil for bikes with a label marked with T4. Can I use it or not?

Thanks, Crow

By anon58258 — On Dec 31, 2009

I emailed Shell themselves, and they said the Rotella T synthetic is an excellent choice for a motorcycle oil.

I also talked with the folks at Royal Purple, and they said there was nothing wrong with using their High Performance Motor Oil found on the shelves at many auto stores. Gosh, I've even used Castrol GTX 10w-30 for years in one of my third gen. Honda Magnas and never had a clutch go or slip. I don't know what the fuss is all about.

I use either Rotella T synth or RP oil in my Yamaha FZ1 (2008 model), and have logged 8k trouble free miles so far.

By anon57951 — On Dec 28, 2009

In over 45 years of riding I have always used "car oil" and never had a problem. I have used synthetics since they have been available. I get disgusted seeing the old wives' tales about motorcycle oils repeated over and over. Use the proper weight and change it and the filter regularly.

By anon56072 — On Dec 11, 2009

not all cars have separate sumps for their transmission. in most subarus the transmission shares the engine oil. it seems automotive oil will work, but that doesn't mean that it's the best tool for the job. there are specially formulated motorcycle oils for a reason.

By anon53532 — On Nov 22, 2009

All right. You fellows need to calm down. You're getting nowhere. This information was for helping those who do not know, and if they were confused before imagine what they are thinking now? You just made this website useless.

So all you reading this argument, just use your best judgment and good luck. You'll need it after reading this message board. --TC

By anon49788 — On Oct 22, 2009

Its all confusing Can you use auto synthetic in a motorcycle or not?

By anon49347 — On Oct 20, 2009

I find it quite interesting to see that you recommend automotive oil. It makes me wonder if you are aware that the api changed the performance standards in '96 which causes for lower zinc and phosphorus which protects the wear of mc also that they have friction modifiers which can cause wet clutch slippage. this article certainly is not by a mechanic.

By anon35597 — On Jul 06, 2009

Do the research on oil and you will see that synthetic is far superior to conventional oil in every way. It's all I use in my motorcycles and cars and I tend to use all the available horsepower. No wet clutch problems, ever. There is nothing wrong with modern regular oil and it will work well in all vehicles, *but*, synthetic will last longer, create less sludge, stand up to heat better and reduce wear. It's just better.--John

By Lammy1000 — On Apr 25, 2009

Kilroy, I do not accept your "facts" because in 22 years. of riding all my bikes have had wet clutches and car oil was always used, typically Mobil 1 and Rotella. Even my dirt bikes which take significant clutch abuse have never slipped. Enough with consumers paying rip-off prices for "motorcycle" oil.

By fvasqu01 — On Feb 25, 2009

If you use semi synthetic oil, might as well send your extra expense to the relief center for the Rich People Foundation. All you are doing is throwing your money away. Amzoil is a great product as Mobil1. Shell Rotella Synthetic is great too. At one time or another, I have used these three brands and have never had any trouble with my bikes 38 years. to be exact. All my cars and truck run on Mobil 1.. Why?? Because, I can run to Wal Mart and buy it there... Amzoil is purchased through a dealer or distributor... Shell is much cheaper but it's still great oil..

By anon26352 — On Feb 11, 2009

Automotive oils have friction modifiers that can cause wet clutches in motorcycle engines to burn up quickly. I have changed a few hundred because of unknowing owners. At a cost of $300 to $1100 per clutch, it isn't cheap.

So save yourself the money and quit paying a mechanic. Motorcycle oil isn't much more than auto oils, plus most motorcycles hold less oil than cars. Don't for get to change the filter.

By anon19511 — On Oct 13, 2008

I'd listen to Kilroy. The one thing that most people don't notice is that even though cars and motorcycles share the same engine design, there is a fundamental difference. Motorcycles share their oil with the transmission while cars have separate sumps for the transmission. Adding friction modifiers to your engine may sound fine but it has an adverse affect on your clutch. It's just the place where you really don't want any slip.

Also I've used Motul Synthetic in my V-Strom and rode it across Canada and back. The Synthetic is made for motorcycles and it ran fine. It even seemed to have cured the notchy transmissions that Suzuki's seem to have.

By anon14711 — On Jun 22, 2008

So does this still apply about car oils vs. motorcylce oils if your bike says 4 stroke engine?

By anon6275 — On Dec 21, 2007

I use synthetic auto Oils in many bikes for years.

Synthetic is the way to go!

Most bikes only say 10w40.

Just worry with that.

And many of my friends do the same.

I even remember a website where a guy said he used mobile one on a cbr900 for 200.000 miles with no problems whatsoever!

Wet clutches ... what's next the buggy man?

By anon1287 — On May 23, 2007

Kilroy -- you state - "it is not recommended to use full synthetics in motorcycles semi-synthetics maybe but not full." I question this simply because if you go to a circuit, you will easily see all the racers using the full synthetic oils. Being 52yrs old now and racing street and dirt along with owning my fair share of street motorcycles, I will say using Rotella oils are the best overall.

By Kilroy — On May 09, 2007

OK so something I would like to know where did you get your info consering the compatibility of car oils vs. motorcycle oils. Also are you referring to motorcycles with wet clutches, or motorcycles with separate transmisions? If its the former you most likely have damned people to an early clutch replacment, as the blended oils that are used in cars will make them slip. also it is not recommended to use full synthetics in motorcycles semi-synthetics maybe but not full. Now if it was not important to run a specific oil type in a bike why then do many of today's oil brands offer motorcycle oils? with over 15 years of service work on bikes I have seen first hand what can come from using the wrong oils in a bike. There are many oils out there you can run but please stick with one that states its blended for motorcycles.

The oil companies and there salesmen will always say its safe to run there brand when asked, but when it comes to damage due to running their car oil in a motorcycle they are quick to piont out that its not designed to run in a motorcycle!

Mary McMahon

Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a...

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