10W/50 OR 15W/50 PETROLEUM-BASED OIL? ;-)

The greater the spread between the Winter weight and the Summer weight, the less stable the oil is, especially on a petroleum oil.

Kind of mentioned above with a correction, AMSOIL makes a 20W-50 M/C Specific oil.. Assuming by your name here, you are riding a Honda, I use to own a Honda CB 750 K-4, it should call for a 10W-40 which AMSOIL also makes in a MotorCycle Specific oil.

Regardless of which oil you choose, I always recommend a M/C Specific oil with a JASO Rating of MA, or, better yet MA 2, but never MB.. These are Clutch Performance ratings.

www.amsoil.com/lit/g2156.pdf Link to M/C Oil tests...

Many think that Automotive oil can be used with no problems in a M/C, but oils have changed in the past few years and even in the last 12 months. ZDP has been Reduced/Removed from Automotive and even Diesel oils which is the "Sacrificial Lamb" for cam wear on Flat Tappet cams. It has been taken out of oils as new vehicles utilize Roller Cams. The exception is MotorCycles and small engines. Hence, use the proper oil, a couple dollars in oil is not worth an engine rebuild.


Doc

Doc's right.

I've seen some really weird **** happen with 15-50. I've seen it where the oil level was absolutely perfect when warm, but when HOT the oil was overflowing! Bizarre!!!

Multi weight is achieved by adding polymers to oil. These long chain polymers curl up when cold (reducing viscosity) and unravel when warm (raising viscosity) in that way they can provide thinner oil at start-up but still retain the warm protection of a heavier weight oil. Oil without these polymers is NOT multi-weight! Sae 30, for example, has no polymers so it is 30 weight at ALL TIMES. 10w-40, however, is essentially Sae 10 that has had polymers added. Polymer can't make oil thinner, only thicker, so you have to start with a base of whatever weight you want when cold. So they add these heat sensitive polymers to this 10 weight oil and get 10w-40 out of it. It has the cold flow-ability of a 10 weight oil, and the warm flow-ability of a 40 weight oil. However, it is STILL a 10 weight oil under the additives. The same holds true for 15w-50. It's a 15 weight oil with sooooo much polymers added that it has the warm flow-ability of a 50 weight oil. The problem with these polymers is that when they unravel, they can get caught in between the gears and other mechanical parts in the engine and quite literally chopped in two. Once that happens, that polymer chain doesn't work any more. That right there, my friends, is exactly why oil viscosity breaks down over time. The polymers all get chopped up and cooked apart and they don't work anymore so the oil begins to revert to its base weight. In 10w-40, if all of the polymers are broken down, you are left with what? That's right, 10 weight! Very good class!!!!!!!!!

Synthetic oils don't suffer from this problem. Well, hydrocracked synthetics do, but PAO's (mobil one) and esters (what Amsoil used to use I think) are designed in a lab and don't require the use of polymers so there's nothing to break down. That's why you hear about their viscosity lasting longer and offering better protection.

With the motors I have rebuilt, having seen with my own eyes the benefits of synthetics, all, and I mean ALL of my bikes run Amsoil motorcycle oil. I have never had to rebuild another engine after the switch either, EVER EVER EVER! DO NOT, however, EVER, under any circumstances, use regular automotive synthetics in a bike with a wet clutch! While I have heard several people have had good luck with Mobil 1, many many people have burned up their clutches because of the friction modifiers in regular synthetic motor oil. If you use synthetics like I do, only use oil that's specifically for bikes and safe for wet clutches. If you have a Ducati, you can probably run whatever because most of them use dry clutches.

I never recommend anyone use a 50w oil unless the manual calls for it, they are leaking oil, have oil pressure problems, running nitrous or a turbo, or have a gazillion miles on their worn out bike. You will actually have better protection out of a 10w-40, not to mention better mileage and performance. The problem with heavy weight oils, beyond their **** cold protection, is they are very thick, which is fine if you have ENORMOUS cylinder pressure, but on a naturally aspirated engine, it just drags on the crank and the oil pressure gets so high and the oil so thick it ends up going through the oil filter bypass and it NEVER gets FILTERED. That, my friends is a very REAL problem for engines without a whole lot of wear! There is a pressure actuated valve in the filter to allow oil to pass through the filter if the filter is clogged rather than blowing up the motor (a great idea!) but the problem with that is 50w is so thick it doesn't like flowing through the oil galleys and out the bearings so the pressure goes up and blows ball valve bypass on the oil pump, then because it's too thick for the filter media, it opens up that bypass too. Also, if you have an oil cooler, your engine will actually run HOTTER with the heavier weight oil because it doesn't flow through the cooler worth a damn. If you run a 50w oil, and switch BACK to a 10w-40, I guarantee you will see the temp drop if you have a gauge, even without an oil cooler! On boosted motors, or for racing, you use 50 because its thickness takes the pounding of super high cylinder pressures and because it keeps oil pressure up. Race engines have super loose tolerances and the bearings bleed oil like a sieve which results in super low oil pressure. With 50w, the thickness of the oil gets that pressure back up there.

Hey thanks man, I appreciate that, seriously.

Yeah, I know what you mean. What I really don't get is how some people defend dino oil so fervently. I mean, if you like it, that's fine, but I have seen with my own eyes and felt with my own hands the differences in motors run on synthetic and dino. That goes soooooo far beyond mere "preference".

In my very honest and most truly humble opinion, those who say "Ive been running BrandX oil for X many years without any trouble." in referring to plain-o group 1 or 2 oil simply had not run their engines long enough in that many years. There will come a time in every engine where synthetics have made, or would have made a difference. Is it worth paying more to run synthetics so that one day you don't loose compression on a couple holes and have to do a rebuild? I think so.

How many synthetic oil changes could you do with the 3 or 4 thousand dollars you could save by not having to rebuild a car engine??

I HAVE seen the difference in motors I've worked on, it's not just "brand preference" at that point, it's knowledge and experience which is waaaaay above and beyond preference! You KNOW what I mean. Amsoil is the only oil out there that I'm aware of that really does what it says and lives up to their marketing babble. It really is that good, and that's why all my cars, bikes, and even lawn equipment run Amsoil. The ONLY thing "preference" means is the oil companies advertising campaign WORKED. That exposes people as the sheep they really are. They just don't know any better. And just like a horse, you can lead them to water, but you can't make them drink. And those who say "it's good enough" just don't care "enough" either way. That's fine, I suppose, but I would never buy anything used from them!

You should make a giant sign 200' tall that says that..... Today, there IS a difference!

You nailed it with that one dude.

bob weeks said:

thanks oil doc I am going to synthetics on every thing next change my dealer,
has told me that it is so much better and wont break down like regular oil will
I do know something about oil ,Work in refrigeration and we must use the correct oil or the system will get stopped up because of the oil & refrigerant mix
must be wright or it will course it to fail much sooner thanks for the info I understand about using the stuff for every thing even your lawn mower,
use the wright lub and it will last & last if not you will be buying a norther one ,
sooner than you thought ,Biker Bob

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Most people think of oil as a way to reduce wear. And that's true. The only thing it does is reduce wear on friction surfaces. Synthetics are a lot different though. They're almost a wear arrestor. In other words, once you have worked all of the conventional oil out of the system (which might take several oil changes), there's almost ZERO wear from that day forward. Whatever wear you have in your engine now, when you switch, you will have in another 100,000 miles from now. There are some exceptions though. It won't save an otherwise dying engine. If you burned the bearings, spun a rod bearing, or what not, it's not going to help that and the engine will continue on its path towards destruction regardless of the oil used. But if you take a motor with 10,000 miles on it that's always run conventional oil and tear it down, take pictures and note the wear on its internals, and then you switch to synthetics and run it an additional 100,000 miles and tear it apart, you will see almost the EXACT same wear you had at 10,000 miles! These oils are so good, in fact, that they can actually keep a new engine from breaking in! Seriously! It's amazing sh!t!

Went and looked (I keep the filters and oil on hand, my own personal stock-pile LOL), yeah, the oil filters are definitely Amsoil EA.

I found a long time ago that keeping oil and filters on hand keeps me changing my oil when I need to and eliminates the procrastination factor. Used to, when I needed an oil change, I would first need to go buy the oil and filters. We didn't used to have an Amsoil dealer here so I had to mail order it of their website. I would forget, or put it off, or do it tomorrow, or whatever, and it just wasn't getting done on time. Plus, it's expensive stuff so you might put it off until you have some more cash on hand or whatever. Well, now, every year I save up a few hundred bucks and buy everything I need for everything that uses oil to last me at least a year or more. It costs a few hundred bucks, but I never need to worry about it after that. I know that whenever I feel liking wrenching on something, changing the oil, swapping out pistons, top ends, doing a port and polish, new cams, or just regular maintenance, I have the oil and filters on hand and never have to go hunt it down, order it, or what not.

It really makes that part of living with the bikes a lot easier. I keep lots of stuff on hand. I have tons of carb kits, at least 4 of every jet you can think of, a great selection of o-rings, extra pistons and rings, lots of gasket kits, 5, 6 brand new cans of Silkolene Race chain lube, parts washer, small paint booth, cans and cans of carb cleaner, all kinds of sealant and RTV, 4 55 gallon drums of VP race gas, two 55 of methanol, even one 55 of nitro methane (I mix my own model engine fuel too, for boats, planes, heli's and cars) all with pneumatic fuel pumps (except the nitro), a bike lift, air everything, a tire changer and balancer, all kinds of tires, I could go on and on (I think I just did! OOPS!). I could quite literally go into business as a motorcycle mechanic LOL!!

But, I try to be very humble and learn from the masters and always, always remember that I am not a pro and I respect those who are! Thanks Doc!