I know a really good mechanic this guy knows his stuff. I was skeptical at first about switching over to a full synthetic 5W30 Mobil 1 Formula. Having always used Castrol GTX Drive Hard, and other brands of "high mileage" oils because my car was close to 100K now its at 127K I always assumed that switching to a thinner oil like Mobil 1 may cause problems. However, 3-3500 miles ago I made a switch over to Mobil 1 based on the advice of my mechanic saying if the engine is in good running condition with no visible leaks then the switch to full synthetic should be fine. Well I made the switch and I have had absolutely no problems. No leaks, no smoke, normal consumption. So why do a lot of people here say that switching over is bad???

 

Dunno. But Mobil 1 5W30 is no "thinner" than Castrol GTX dyno 5W30.

 

I dont know either. I used to have slow oil leak, but after I put Mobil 1 SuperSyn it stopped. That was at 124,000 miles!

 

I always used 10W30, but that's good to know!

 

my max has over 235+K on it and since 40K is its only been gettin Mobil 1 Fully Synth and it runs great... i dunno why its bad, maybe its cause after soo much ware and tare the motor needs something thicker, and its not used to thinner oil... lol i know im probably wrong on this .... but wat i heard its worst to put in regular oil after useing only synthetic oil...

 

i couldnt tell you either but every car i own with the exeption of my 95 firebird has mobile 1, and every time i try to switch oil my vehicle starts using oil so i decided not to do that anymore.

 

ohh i allways put in 5W30 for the summer, and 10W30 for winter... i dunno my dad did this for some odd reason and now i do it too... i dunno if its wrong or right so gime some feedback....

 

the mollecules are more uniform in size and overall smaller they find ways to find leaks that other oils dont. I think u could switch to syn but i wouldnt even if the car was brand new i think it is highly overrated. if u must i would recomned a syn blend if u dont go to Castrol GTX

 

AND its real bad to go back to reg. oil from syn dont do that either

 

Uniform yes. Smaller no.

Syn blends are a waste of time.

And the statement that you can't switch back and forth is false. Read the fluids/lubricants section sometime.

 

1) The info they are getting is from "old school" mechanics.
2) They believe in myths that have no evidence to back them up.
3) They make their own conclusions based on #2.

Personally I'd stick with Castrol GTX. It out preformed Amsoil synthetic oil in my car. Blackstone labs has done my oil analysis since day one, and my switch to Amsoil with an extended drain interval showed much more wear then a normal 3K - 4K change interval with Castrol GTX. That information can be seen in the spread sheet Bill keeps in the lubrications section on this board. Castrol GTX is one of the best in wear protection on the entire spread sheet. Mobil 1 also being one of the best.

 

from what i heard if u do that your valve seals will go bad... ???

 

Well Mobil1 has been known to be the best oil out there. I've read it in articles, and other credible resources. I've heard that some people don't put Mobil 1 in brand new cars because it protects the engine that well and that they put it in at a later time. I think there was a thread about something like that here once. The thread didn't talk about Syn. oil in high mileage engines but did talk about how Mobil1 was all that it was cracked up to be.

 

it may be the best but its much much more i cant justify changing my oil every 10 or 12 k miles no matter if it resists thermal breakdown or not it still gets just as dirty and contaminated as a regular oil

 

You're doing it backwards, you should put the less viscous (5w-30) in for the winter and the more viscous (10w-30) in when its warmer out. The first number in the oil weight relates to its viscosity when the engine is cold, the smaller the # the less viscous the oil is at low temps.

 

thanks.. for the info and my post was wrong im doin it the right way i just posted it wrong.oopss.... im puttin oil just like u said...

 

i concur with what he just said, you want less viscous in the winter time because it flows better when its cold out. you dont want engine components running even a few more seconds without enough oil. in the summer this isn't an issue, so thicker oil protects from the engine heat and summer heat.

 

cool.. cause ive been doin that since the first days i started to drive.. my dad allways told me to do that when i changed oil i just forgot his reasons.. but i see now thanks guys...

 

Another FALSE statement.

 

You sure about that?? You compared a GTX @ 3,000 miles vs Amsoil at 5,000-7,000 miles. Not the same.

 

I just switched to Mobil 1 from GTX at 195k miles.

Now my engine makes a frowny face. The myth is TRUE!

 

http://www.amsoil.com/articlespr/articlemyths.htm
http://www.mobil1.com/why/myths.jsp

 

"Another FALSE statement. "

how in hell is that false its my opinion. dont tell me what i can and cant think

 

This is NOT an opinion. You stated this as "fact" it still gets just as dirty and contaminated as a regular oil

Opinion or not, it is FALSE.

 

and yes read all you want from the companies that produce these products there not going to say anything bad about what there trying to sell

 

Nope I read the oil analysis provided by members. Not companies.

Where are you getting YOUR information?????

 

ok i was half wrong the end i did state as a fact and i ment it as an opinion but how does it not get as dirty and contaniminated? does it completly seal your engine and stop outside elements from coming in? is it magical? does it get blessed by harry houdini when it leaves the factory?

 

i was reffering to this post "http://www.amsoil.com/articlespr/articlemyths.htm
http://www.mobil1.com/why/myths.jsp"
and those companies DO make these oils ( iam stating this as a fact)

 

I thought that's what the oil FILTER was for?????? Outside elements?? I thought that's what an air FILTER was for??????

 

when i say elements iam mostly reffering to water which does get into oil and a oil filter does not catch that if im not mistaken

 

WTF? How does water get into the oil? You drive though rivers or something? Exactly how much "water" is accumulated in the oil over 3-4,000 miles???? You must have some data on that right?

 

but you know what i could care less what oil you or anyone else uses so go nutz and get the synthetic if u want it (dirrected to HarrisH) and let us know how it works for you

 

humidity in the air is not stopped by a air filter some of it may be but not all.

i'm just conveying the info i recieved from a past CEO of honda who gave a speech on this and said most of what ive said here today and also said that the biggest waste of money in the automotive buiness is over(unnecessary)protection

 

Your mechanic is 100% right. Don't know what the exact benefits would be on an engine that already has 100k miles on it though. But if the engine doesn't use oil and doesn't leak, it's fine.

Most people say don't use synthetics on high miler motors and it tends to use more oil and leak more. But that's not the oil's fault. Those engines are probably already worn and have slight leaks anyway. They should probably be run on dino oil anyway. Possibly a thicker grade and be changed sooner anyway. A GOOD running modern engine doesn't use up the addtive packages very fast and the oil stays clean longer.

 

Humidity in the air huh? And I guess 99% of that doesn't get burnt though the process called combustion?? You either didn't understand what the CEO was stating or he doesn't know what he's talking about.

If you think synthetics are the "biggest waste of $" you have absolutely no idea what synthetics are all about, what they do or how they work. Much less comment on if this gentlemen should use it or not. IMHO!

 

Maybe you will actually learn something today.

Motor Oil
The myths, facts, and mysteries of the slippery stuff that keeps your engine happy.
By Gordon Jennings, Originally published in Motorcyclist, October 1996


Here's the bottom line when it comes to motor oils: you really cant go wrong by following the recommendations given in your owner's manual. Your motorcycle's maker has dyno-tested its engine with a crankcase full of the specified oil, or one with the same American Petroleum Institute (API) rating. You can be sure that particular oil will do the job. Will it do the job better than any other oil? Will it do the job if the engine is no longer as its manufacturer made it? Not Necessarily, as you will learn by reading further.
The API's ratings once went from 'SA' (guaranteed to be oil) through the alphabet to 'SE' and was extended to 'SE/CC' (you cant drive a nail through a film of this stuff.) Today the API has fewer performance grades, only 'SH' and 'SG' for spark-ignition engines, with an 'SH/CD' rating for oils good enough to be used in passenger-car diesels. The motor oils bearing these API markings have been test-certified for today's engines, which are in turn constructed with these oils in mind.
You should be aware that motor oils are now being compounded not just for lubrication, but to improve fuel economy as well. Oils have always been compounded with a thought for fluid drag; this is the first time its been made a priority. The API has two economy ratings: "energy conserving" for motor oils that yield a 1.5% reduction in fuel consumption as compared with a reference oil; "energy conserving II" is an oil that provides a 2.7% drop in fuel consumption.
As you might expect, energy conserving oils drag reduction benefits also show up as increases horsepower. Both thermal and mechanical losses diminish the power liberated in the combustion process on its way to the output shaft. The work of pumping air in and out of the engine accounts for the majority of the mechanical losses. The rest is mostly lost to fluid drag on the piston, which is, all other things being equal, largely a function of oil viscosity.
Friction exists even in the absence of actual contact between opposed surfaces. The cylinder wall's oil film normally prevents it from being touched by the piston, it is a source of friction itself, if we take that to mean a resistance to relative motion. Millions of molecules on each side of the gap try to stick together and get pulled apart. The sum of millions of molecule's minute resistance to separation comprises viscous drag, the source of most friction in a running engine.
Viscosity aside, the most important property of an oil is that it be "oily." Introducing any liquid between a piston and cylinder wall, for example, will reduce friction between the two surfaces. The degree to which friction will be reduced is, broadly speaking, a function of the liquid's viscosity. But maple syrup and motor oil of essentially identical viscosity do not lubricate equally, as you discover by rubbing samples of each between thumb and forefinger.
If "oiliness" were the only quality to be considered in choosing motor oils, we'd be squeezing all ours from castor beans. Castor oil, the smell of which once perfumed the air at motor races, is the oiliest of oils and it remains in some respects the supreme lubricant. It does oxidize too readily, however, forming ring-sticking gums and varnishes, and daubing fouling deposits on spark plugs. In a running engine, castor oil goes right to work gluing piston rings in their grooves and slathering gum and varnish everywhere. You wouldn't want it in any engine that can survive without its help.
But castor oil, a mixture of ricinoleic and triricinoleic glycerides, plus 10-12% of other fatty acids, remains one of the best lubricants for 2-stroke racing engines. Castor oil clings to metal with such tenacity it cannot be removed except by machining. It is an exceptionally effective film lubricant.
Oil forming a hydrodynamic wedge between surfaces keeps pistons and bushing-type bearings from metal-to-metal contact. Viscosity pulls the oil between a moving piston and its adjacent cylinder wall, or a shaft and a bearing, and pressurizes the gap. The pressure increases with viscosity and speed, and a well-designed engine almost totally prevents scrubbing contact.
The qualifying "almost" is needed because hydrodynamic action is not present in an engine at start-up, and it collapses around the pistons and rings at the end of their strokes. Under these conditions, parts are protected only by film lubrication, which is provided by the dipolarity of the oil molecules. The molecules behave like tiny magnets and adhere to ferrous metals and each other.
One of the great improvements in motor oils came circa 1950, when when the detergent/dispersant additives developed for diesels came into more general use. Alas these brought with them unfortunate consequences for old, high-milage engines. In those, the detergents sometimes dislodged great clots of oxidized oil filth to clog filters and oil passages. Engine failures caused by detritus liberated in this manner put additive oils in bad repute, with the results that some people still buy and use straight non-additive oils.
The first oil additive was probably the spoonful of sulfur old-time truck operators tossed into axle and transmission housings. The sulfur reacted with gear-tooth steel to give the gears an iron sulfide film. The film was important because the relative speeds between meshing gears is too low to form a fluid wedge strong enough to resist the extremely high gear-tooth loads.
Engines also have points at which loadings can exceed the carrying capacity of the fluid wedge. Take the tiny contact area between the exhaust cam and follower, for example. The load there rises to roughly 1500 pounds for every ounce of valvetrain weight at high engine speeds. Full throttle adds 80 pounds of load for every square inch of valve head area, meaning the load focused on the cam/follower can reach pressures in the order of 20,000 pounds per square inch.
Cams would have to spin much faster than they do (half crank speed) to work up a fluid wedge capable of carrying such high loadings. So the job has to be done with film lubrication, which means a more viscous oil, one with special properties (castor) or an extreme pressure (EP) additive. It's obvious that film lubrication is important, where some of us go wrong is in leaping to the conclusion that those who compound motor oils have overlooked this very point.
Dealer's shelves usually have a selection of flasks filled with liquids I like to call "mouse milk." This stuff reduces the friction in your wallet enough to make money slip out of it, but may not do anything else. About the best you can hope from mouse milk is that it will either be more of the same additives already in good-quality motor oils, or at least not get in the way of the additives that can do something useful.
Film-condition additives usually are chemically and/or thermally reactive. The sulfur- and phosphorus-based compounds react with iron to form slippery iron sulfides, as previously noted, or wear-resistant iron phosphides. Fatty acids, like those in castor oils, react with iron to make low-friction iron soaps.
Thermally reactive "liquid metals" like molybdenum dithiophospate, are oil-soluble chemical compounds; molybdenum sulfide, on the other hand, is a cheap dry-slide lubricant sometimes used in greases. If you put MOS or other dry-slide lubricant powders like colloidal graphite in motor oil, these solids may settle or filter out. Worse, they may become a barrier blocking the more effective reactive additives.
The liquid metals dissolve in oil, like salt in water, and remain in solution at all normal engine operating temperatures. But when friction heats the liquid metal compounds they come apart and their metallic component is plated on the hot spot. This stops the most potent, least obvious wear process in today's filter-protected engines: direct, scrubbing contact between a cam and follower, gear teeth, etc. This contact results in wear largely due to friction welding: Friction melts pinpoint areas of metal on both sides of the contact area, and they weld themselves together. These minute welded particles then break away, and after enough of them are carried off by the oil, the parts need replacement.
The role of liquid metals--usually molybdenum, tungsten, or zinc compounds--is both to interfere with friction welding, and to sacrifice itself to the wear that would otherwise devour engine parts. Unfortunately, phosphorous compounds degrade catalytic converter performance, so the feds limit the amount of additives like zinc dialkyldithiophosphate in motor oils. But in nearly all instances there is enough to last from one oil change to the next.
In the years before we had effective micron-level air and oil filtering, abrasive engine wear was a problem. The typical spark-ignition engine sucks in 10,000 gallons of air for every gallon of fuel it consumes. If you dont filter that air, it carries grit into your bike's engine post-haste. The larger particles do little damage unless they get caught between a valve and its seat, pitting both severely.
Virtually all dust particles are silica or silicon oxide, an extraordinarily hard substance with plenty of sharp edges. Engines with inadequate (or non-existent) air filters eat a huge amount of this grit. The good news is, most of it leaves with the exhaust gases. The bad news? What does stay can do severe damage, whether its in the wrong place or carried around in the wrong oil.
Modern air and oil filters trap just about everything larger than a micron (1/1,000,000th of a meter, or 0.000039 inch) in diameter. Particles of that size are enveloped by the oil film separating an engine's moving parts. Even a very light oil provides this protection. SAE 5 seems watery, but it has a film depth of not less than 0.001 inch, deep enough to submerge particles smaller than 26 microns.
Abrasive wear was a bigger problem back when the typical motorcycle air filter was a coarse screen capable of stopping nothing much smaller than pea gravel. The old gravel strainers gave free passage to the 20-micron grit that does the worst damage, especially to piston rings.
Fine grit was/is still a great killer of roller cranks. Grit becomes embedded in bearing cages and makes them depressingly effective crankpin grinders. You can prevent this kind of damage by using the thick oils, SAE 30 and above, envisioned and reccommended by the people who built these old engines.
Thick, high-viscosity oils are good for enveloping grit. They also do a great job of sealing and cushioning, which are two important functions of all motor oils (much more 30 years ago than today). The aluminum piston alloys in use circa 1960 had high expansion rates and poor high temperature strength. Accordingly, they needed to be surrounded by thick oil, to seal the fire trying to blow past the generous clearances--and to keep them from rattling in their bores.
Thick oils spread the concentrated loads between roller bearings and their races. The mechanism of rolling-element bearing failure usually is "brinelling," fatigue-related flaking, of the inner bearing race. Under load, the race under the roller (or ball) yields minutely as the bearing turns, just as a paved street yields to the weight of a passing truck. And in time the bearing race, much like the street, begins to break up.
Plain insert-type bearings can also fall victim to fatigue failure. You can bring about their early demise by feeding them a too-thick oil, which will turn into a too-thin oil in the bearing. The oil in plain bearings, whether connecting rod inserts or the floating bushings in a supercharger, is heated by fluid shearing. If the oil's viscosity and bearing clearance are properly matched, there will be sufficient oil flowing past the bearing to keep it cool.
When you pour SAE 40 into an engine designed for SAE 10-30, you may intend to protect its bearings with the thicker oil. But the increased oil viscosity , and resulting reduction of flow, can overheat the bearing. The metals used in plain bearings--copper, lead, and aluminum--typically lose half their ambient temperature strength at 200 degrees F. Copper-lead bearings are stressed near their elastic limit at redline crank speeds, even with crankcase oil temperatures below 250 degrees F. Pour in some thick oil, or a "mouse milk" viscosity index improver, and you'll reduce the bearing's oil flow, which will make it hotter and may cause it to fail.
Engine oils are viscosity-rated by subjecting them to the arcane arts of viscometry at 40 degrees F, then heating them and repeating the test at 210 degrees F. When you see a 10W30 rating on an oil, the "W" means the oil's base stock has actually been tested down to zero degrees F with a cold cranking simulator. It is assumed, for purposes of viscosity, that motor oils are "Newtonian" in that their loss of viscosity with temperature (meaning that their rate of loss is fairly constant.) The rate of loss is given as a viscosity index number, and in this respect some oils are better than others.
Multi-grade oils are made so by chemical additives called "viscosity index improvers." These additives contain either colloidally dispersed long-chain molecules that dissolve into true solution as temperature rides, or spiral molecules that open up and get longer with increases in temperature. Both of these actions "thicken" heat-thinned oil. Add the right VI improver and you get, for example, an oil that tests like SAE 10 at 40F, but looks more like SAE 30 at 210F. A multi-grade oil doesnt thicken with increased temperature, it doesnt thin as much as a single-grade oil.
One thing you should know about multi-grade oils is that their VI-improving additives will wear out. You can fool mother nature, but not forever: Long-chain molecules shear apart, so the the 10-30 oil you poured into your motorcycle's engine becomes 10-25 oil after a time, then 10-20, 10-25, right down to 10-10 if you cover enough miles between oil changes.
Over the last couple of decades we have seen the rise of "synthetic" and "synthetic blend" base stocks in motor oils. The big difference between plain old refined oil and synthetic is the the latter is, well, synthesized. When crude oil is refined, it is effectively sifted. The SAE 30 base stock you get in the sifting operation represents an average of molecule sizes, some being larger and others smaller. Shearing in a running engine breaks the big molecules apart faster than the little ones, which reduces the average size of molecules in the oil and thins it.
In contrast, synthetic base stocks' molecules are uniform in size, having been assembled out of fragments in a molecular stew. Synthetic oils also contain none of the waxes that can block low-temperature flow, and none of the instant-sludge crude-oil cruds or aromatics that vaporize and drift away the first time a spark plug fires anywhere near them.
I was not impressed by some of the early synthetic motor oils, which were compounded using cheap glycols as a base. Union Carbide's polyalkylenes oozed past gaskets and seals, some others synthesized from gases returned to gaseous form in the hot engine environment.
The better synthetic base stocks in use today are record-holders on the viscosity index scale. They still need a good squirt of VI booster to qualify as multi-grade oils, but they need less of it than refined base stocks. This is important, as polymeric viscosity index improvers' long molecules are unstable in shear. The less help your SAE 10W30 motor oil needs to meet its high temperature obligations, the longer it will be effective.
Good synthetic motor oils also have better non-newtonian, "apparent viscosity" behaviors. Oil displaying these "kinematically diminished" properties behaves like a thinner oil when rubbing speeds are high enough to build a thick fluid wedge.
Which synthetic oils are best in terms of apparent viscosity? I dont know, and neither does anyone who lacks a laboratory full of expensive, complicated equipment. I also dont know which additives, or how much of each, is present in the containers of motor oil--refined or synthetic--you'll see displayed at dealerships, service stations, and the like. That information is a closely held trade secret.
So after all this talk of motor oils, how do you tell good from bad? The bottom line here is, you buy the label on the container; you buy reputation. When you see a plastic bottle labeled "zowie lube," with small print that says it was packaged by "O'grady's Motor and Hemmroid products," put it back on the shelf and reach for something familiar. When I tell you to buy name-brand products, I'm not just sucking up to this magazine's advertisers.
Castrol is not an advertiser, but I will tell you the company has been making motor oils since we've had motors and I dont think it would knowingly sell you anything that would tarnish it's good name. I've used Castrol's motor oils for both racing and street applications, without disappointment. Refined-based GTX, sold super-cheap at supermarkets everywhere, is a very good motor oil and may be better than some higher-priced synthetics.
Mobil, which is an advertiser, long ago began developing synthetic motor oils and put its considerable technical resources to work creating a good one. They came up with Mobil 1, an oil using mostly polyalphaolefin base stock reinforced with a big percentage of polyol ester, the latter being an especially good lubricant in its own right. Mobil 1 probably is today's best widely-available motor oil. As a result of prepatory research I have done prior to writing this article, I bought (yes, bought!) Mobil 1 for use in my own vehicles
Red Line, an advertiser, is making a name for itself as a source of all-synthetic motor oils, and this company, like Mobil, relies on big percentages of polyol esters in its base stocks. My contacts in two- and four-wheeled racing tell me Red Line's oils are producing excellent results in everything from NASCAR's stockers to motorcycle GP racing's shrieking 2-stroke engines.
Keep in mind that your motorcycle was extensively tested with its cavities full of the lubricants specified by its maker. Motorcycle manufacturers dont test their models on oil specially compounded to keep engines, clutches, and transmissions happy, they instead do the sensible thing and design hardware compatible with the oils they know you'll be able to find. Its the smart thing to do, and it works right up to the point where you ignore their advice.

 

Castrol GTX every 3k....best way to go!

 

an engine that wasnt designed specifically for their use does not need them i do think there a waste of $$ and i do think that harrish should hear both sides arguments sorry if u think im wrong but i was just voicing what the head of a major automobile comapany had said and what i felt (mostly based on what he and other mechanics had said) i could be wrong but i still trust what ive heard and i will continue to use my dinos. as for what you do..the choice is yours

 

2 things we dont have motorcycles and read the first sentence. again do what you want

 

"does not need" does not = cannot benefit or is not better. Thanks