How long can i go without changing oil safely?

[kntalan]

Hello,

I just was wondering how long i can go safely between oil changes. The reason i ask is because i am putting arround 850+ miles a week on my bike, and that is just back and forth to work 6 days a week. it is almost 140mile roundtrip to and from work, that times 6 days is 840miles. So i have to theoretically change oil at 3000 miles, but that is just about 3.5 weeks of riding. I ride mostly interstate and all paved roads..ect. The oil that i use is Mobil 1 synthetic 20-50w. I know that a 30 dollar oil change isn't that expensive and all and that some people will say pay a little now(for oil change) or a lot later(major engine work). I don't mind paying and doing oil changes, but my question is am i overkilling on oil changes? is the oil with 3000 miles on it still good? I am running a Fram chrome oil filter also.

Thanks..Have a good day...Tom

P.S. I don't want to start a oil war here, i just want to know how long synthetic oil is good for before it starts breaking down..ect...

[SportsterBart]

I'll go out on a limb here and say you can safely go 5K or more with synthetic.

I hate oil threads btw :doh :laugh ;)


Bart

[gronk62]

I'll go out on a limb here and say you can safely go 5K or more with synthetic.

I hate oil threads btw :doh :laugh ;)


Bart

+1


________

[shotgun46]

Mobil 1 synthetic 20-50w. i would say 5000 miles is ok ! according to the moco its even ok !

[SportsterBart]

Thanks Gronk ;)


Bart

[Bite Me]

This may be subjective or objective or both... but here goes... Oil is normaly described as honey colored, thats normal oil. When oil has been run a bit it will get a sort of red/amber tint to it. It is at its best right then when it has the red/amber tint. It is lubricating then at a much hight level than when it was even put into the bike/car or what ever brand new. When it passes that color state it is going over the hill and it should be changed. Learned this back in the 80's in lubrication seminars while I worked in the industry. Have since put well over 100k on more than one v-twin using this color watching deal... Yep they may say 5k but hard driving rough terrain high temps short bar hops all these things come into play so from my stand point I just keep watching it and when the color changes I change it.

[Gyahmers]

I tend to change my oil (syn3) every 5k but after reading what Bite Me had to say I'm going to keep an eye on the color more often and see.

[Gone]

Whatever you decide to do about your oil change intervals, remember clean oil is the cheapest thing you'll ever do to your engine.

[Gary7]

Under your driving condition I think you could go at least 5000 miles between changes. To know for sure, do an oil analysis.

Check out the Used Oil Analysis forum over at BOBISTHEOILGUY. You can see there how people use oil analysis to help them determine just how safely they can extend their oil drains. I personally use the services of Terry Dyson.

[Gone]

the most important part of the oil change is changing of the filter, it may sound stupid but lots of people only change their filter every other oil change. I am a machine repairman by trade and have talked to several oil engineers and they all said in trucks and cars to change your synth. oil every 20,000 miles or once a years which ever comes first but change your filter every 5,000 miles. syn. oil doesn't break down like dino juice but you still need to change the filter to get the particles out. if your oil doesn't change color it is not doing its job. in other words if you change your synth. oil and filter every 5,000 miles you are fine. your oil has 3 jobs - lubrication- cooling - and cleaning the motor. Dave

[t.c. Johnson]

Anyone use one of those paper towel 'bypass filters' to extend their oil's range?
Using syn, oil analysis and a bypass filter your range could be almost unlimited until the oil analysis showed a reason to change the oil.
I don't know where you would put the thing - they are pretty large.
(probably more suitable for a BT - Bert take note)

[joe66]

If you go to any of the diesel pickup website/forums, it's not unusual to find people going 20- 30,000 miles between oil changes when using syn-oil's. Most change filters every 3-4,000 miles and just top off the engine. Some of them do use one of the oil analysis services to check the condition of the oil from time to time. Since we're talking 11 to 15 qt's on a diesel pickup, an oil change can be big bucks. But then, diesel engine repairs are even more.

[ken01976]

just change it every 3000 or 6 months yerself using regular dyno oil. Dont cost much.

[sportysrock]

From the AMSOIL MCV product page:

"SERVICE LIFE
Recommended for use up to twice the motorcycle manufacturer change interval (miles/hours) or one year, whichever comes first, in engines, transmissions and primary chaincases.

For Big Twin Harley-Davidson transmissions only, follow the Harley-Davidson recommended drain interval for synthetic oil of up to 20,000 miles or one year, whichever comes first.

When using an engine filter other than AMSOIL Ea, change the filter at standard intervals."

My '04 says changes at 1,000 miles and every 5,000 miles or annually, twice that interval is 10,000 miles of course. Since you are doing long regular trips instead of shorter rides, the startup wear particles are minimized too. With regular filter changes, and oil analysis I wouldn't doubt you could go 15,000 miles, but would probably limit it to 10,000 miles. AMSOIL will cover you if you experience an oil related failure.

[gronk62]

All this talk about oil color makes me wonder.

My bro has 8 diesel engined vehicles on his farm.

The engine oil gets changed at or close to the recommended service intervals for each vehicle.

Long before these intervals are reached the oil has already turned black.

When I asked the diesel mechanic about this he says its normal and it doesn't mean the oil is not doin' its job.

If the oil got changed everytime it started to get a little discolored it would cost my bro a fortune and he'd be gettin' it done every few weeks.

I think a lot of people are just way to anal about oil.

Yes I agree its cheap insurance but there's no need to go overboard.

[Moved On / My Own Choice]

I don't think the color analysis is valid anymore. Oils (well not the oil itself, but the additive packages) have changed TREMENDOUSLY since the 89s.


the most important part of the oil change is changing of the filter, it may sound stupid but lots of people only change their filter every other oil change. I am a machine repairman by trade and have talked to several oil engineers and they all said in trucks and cars to change your synth. oil every 20,000 miles or once a years which ever comes first but change your filter every 5,000 miles. syn. oil doesn't break down like dino juice but you still need to change the filter to get the particles out. if your oil doesn't change color it is not doing its job. in other words if you change your synth. oil and filter every 5,000 miles you are fine. your oil has 3 jobs - lubrication- cooling - and cleaning the motor. Dave

Some good points here.

Honestly, if I were putting the amount of miles the OP was putting on his bike, I'd spring for some oil analysis for a couple of weeks. One sample per week or per 2-3k miles AFTER you've reached 5k and THEN YOU WILL TRULY KNOW WHEN TO CHANGE YOUR OIL!

I BETCHA it's over 10k for you.

As long as the bike is getting up to temp, you're not in excessively dirty conditions, you don't sit and idle the thing excessively.

Then I BETCHA it's over 10k!

Kev

[Moved On / My Own Choice]

Joe66 - great point. And let's remember, that as hard as an air-cooled Harley is on oil, a diesel motor is probably harder on it (as long as temps in the air-cooled Harley motor stay below 300 degrees F).


just change it every 3000 or 6 months yerself using regular dyno oil. Dont cost much.

Ken, I'm not getting on your case, well, ok, scratch that I am. But do you ever want to just bitch-slap someone for not reading the original F'n post.

The guy puts 3k miles on his bike every 3 1/2 f'n weeks. It is STUPID to use dyno juice and change oil more often than every month! Just STUPID. It's a waste of oil, of oil filters, of time, of effort.

He's never going to see 6 months.

NEVER at that rate.

Kev

[Moved On / My Own Choice]

All this talk about oil color makes me wonder.

My bro has 8 diesel engined vehicles on his farm.

The engine oil gets changed at or close to the recommended service intervals for each vehicle.

Long before these intervals are reached the oil has already turned black.

When I asked the diesel mechanic about this he says its normal and it doesn't mean the oil is not doin' its job.

If the oil got changed everytime it started to get a little discolored it would cost my bro a fortune and he'd be gettin' it done every few weeks.

I think a lot of people are just way to anal about oil.

Yes I agree its cheap insurance but there's no need to go overboard.


:clap :clap :clap

[ken01976]

Joe66 - great point. And let's remember, that as hard as an air-cooled Harley is on oil, a diesel motor is probably harder on it (as long as temps in the air-cooled Harley motor stay below 300 degrees F).




Ken, I'm not getting on your case, well, ok, scratch that I am. But do you ever want to just bitch-slap someone for not reading the original F'n post.

The guy puts 3k miles on his bike every 3 1/2 f'n weeks. It is STUPID to use dyno juice and change oil more often than every month! Just STUPID. It's a waste of oil, of oil filters, of time, of effort.

He's never going to see 6 months.

NEVER at that rate.

Kev
Hey Kev thats what that OR between 3000/6 months means. ORRRrrrrrrr.
So he changes it every month. So what, whats that 4 minutes at most and 14 bucks. :frownthre I'd love to strangle you.:smoke

[Moved On / My Own Choice]

Hey Kev thats what that OR between 3000/6 months means. ORRRrrrrrrr.
So he changes it every month. So what, whats that 4 minutes at most and 14 bucks. :frownthre I'd love to strangle you.:smoke


I saw the Or part, but that was my point. Changing oil THAT often is just silly. It's not the money, it's the natural resource. How much of that oil comes from the middle east just out of curiosity?

It's just so un-necessary with the quality of modern oils.

I'd love to strangle you.:smoke

:doh :laugh :laugh :clap

Fair enough my friend, fair enough!

RIDE SAFE!!!!

Kev

[sportysrock]

Suppose you put in a synthetic at $7.00 a quart, and a filter at $10.00. 4 quarts and filter is $38.00 and you ride for 10,000 miles or a year. Now suppose you add HD dino oil and a filter - the same service costs $21.00 for 5,000 miles. You are doing the labor in both cases and disposing of the waste. The dino oil changes cost you $42.00 for the 10,000 miles.

Using the dino oil; you are wasting your time, your bike runs hotter, you have more engine wear, you have more oil waste and disposal issues, and your engine accumulates deposits leading to sludge buildup. That is how I got started using synthetic oil in my bike.

[ken01976]

Suppose you put in a synthetic at $7.00 a quart, and a filter at $10.00. 4 quarts and filter is $38.00 and you ride for 10,000 miles or a year. Now suppose you add HD dino oil and a filter - the same service costs $21.00 for 5,000 miles. You are doing the labor in both cases and disposing of the waste. The dino oil changes cost you $42.00 for the 10,000 miles.

Using the dino oil; you are wasting your time, your bike runs hotter, you have more engine wear, you have more oil waste and disposal issues, and your engine accumulates deposits leading to sludge buildup. That is how I got started using synthetic oil in my bike.

I don't care what the books say, I'd never go 10,000 miles on any type of oil even if JC came down and blessed it himself. Every 3000 be it syn or dyno.

[Moved On / My Own Choice]

I don't care what the books say, I'd never go 10,000 miles on any type of oil even if JC came down and blessed it himself. Every 3000 be it syn or dyno.


Then don't use synth, because other than slightly lower operating temperatures and potentially better protection against catastrophic failure, you'd be wasting your money.

[sportysrock]

... So he changes it every month. So what, whats that 4 minutes at most and 14 bucks ...

I don't care what the books say, I'd never go 10,000 miles on any type of oil even if JC came down and blessed it himself. Every 3000 be it syn or dyno.

I'm sorry to say it, but you don't make a logical argument with your "4 minute, $14.00" oil changes, why don't you be realistic? The guy would spend all his time wrenching when he's not working.

Do what ever YOU want, and I will continue to be a synthetic lubricant zealot. :laugh

[ken01976]

I'd use syn if it dropped in price, I still wouldn't trust it/or the filter to go over 3000 miles.

[gronk62]

I'd use syn if it dropped in price, I still wouldn't trust it/or the filter to go over 3000 miles.
Based on what credible information?

[Takingabreak]

I am a ASE Master-tech and a Machinist.

3000 miles OR 3 months.

[gronk62]

I am a ASE Master-tech and a Machinist.

3000 miles OR 3 months.
A short quote from the ASE Master-Tech website..

...Oil changes have generally been done around the 3,000-mile interval. With the introduction of synthetic motor oil, intervals have been extended to 7,500 miles or so....

[Gary7]

I am a ASE Master-tech and a Machinist.

3000 miles OR 3 months.

And how many credits in tribology did you have to take to get that ASE certification? ;)

[Oly-rider]

"Tribology is the science and technology of friction, lubrication, and wear, derived from the Greek tribo meaning "I rub". Formally defined, it is the science and technology of interacting surfaces in relative motion and all practices related thereto." From Wikipedia, the free encyclopedia

I had to look that one up. I didn't go to a huge school, but I have never seen a class in this offered. Maybe it's a regional thing.

[Takingabreak]

And how many credits in tribology did you have to take to get that ASE certification? ;)


I see you swallowed a Dictionary there Gary.:geek

Regardless of who refines it, Dino or synthetic, any oil in a Gas Engine will be subject to the same heating/cooling cycles, water absorption (From moisture) and of course the introduction of blow-by that carries gasoline with it. This mixture under heat can cause sludge to build up, and that carbonize and restrict the flow of oil through the system.
The water and gas break down the lubrication abilities and by 3000 mile or three months, it can get to the point that corrosion and wear can become an Issue.

After 28 years of working on Engines, i am sure I have rebuilt more engines then you have seen.

[Moved On / My Own Choice]

I see you swallowed a Dictionary there Gary.:geek

Regardless of who refines it, Dino or synthetic, any oil in a Gas Engine will be subject to the same heating/cooling cycles, water absorption (From moisture) and of course the introduction of blow-by that carries gasoline with it. This mixture under heat can cause sludge to build up, and that carbonize and restrict the flow of oil through the system.
The water and gas break down the lubrication abilities and by 3000 mile or three months, it can get to the point that corrosion and wear can become an Issue.
After 28 years of working on Engines, i am sure I have rebuilt more engines then you have seen.


I think you're missing a critical word there

"CAN"

The water and gas CAN break down bla bla bla...

But how many Harley motors you ever see with a sludge problem?

If you're not jetted stupid rich and the motor comes up to temp most of the time, then you're not going to see a water issue.

I know we're not going to be changing any minds here, but it amazes me how reluctant people are to look at the evidence.

Maybe Gary will take some oil analysis samples.

Maybe I should too.

K

[johnnysquire]

Did anyone read the Bussy report linked (http://www.sportster.org/tech/)over at XLList? Seems to shoot holes in the black = bad, new=good theory. I seem to remember that Jiffy Lube started the whole 3K to an oil change (when manufacturer intervals were longer) back in the 80s, with obvious motives.

After all, the service intervals are written by the lawyers and finance guys, trying to make sure they don't pay warranty claims, not the engineers. I'll bet the rough service intervals are more to make sure the company avoids warranty claims ("we don't have to pay because you subjected the vehicle to rough service and didn't change the tranny oil at 32K, leading to the failure") than sound maintenance, with the possible exception of cabs, police cars and desert dwellers.

Personally, I've always followed manufacturer's service intervals as a conservative estimate. Results? Over 100K trouble free miles on each of 5 cars so far (two Hondas, a pre-Chrysler Jeep, a BMW and a Ford van).

[Gary7]

I see you swallowed a Dictionary there Gary.:geek

I guess that's one way of characterizing someone with a BA, MA, Drs, and JD. :geek

Regardless of who refines it, Dino or synthetic, any oil in a Gas Engine will be subject to the same heating/cooling cycles, water absorption (From moisture) and of course the introduction of blow-by that carries gasoline with it. This mixture under heat can cause sludge to build up, and that carbonize and restrict the flow of oil through the system.
The water and gas break down the lubrication abilities and by 3000 mile or three months, it can get to the point that corrosion and wear can become an Issue.

Only under the most extraordinary circumstances (or in an already neglected engine) would that be the case. Modern base oil technology as well as modern additive packages can easily protect well beyond 3000 miles under virtually any driving conditions. Thousands of UOAs posted over on BITOG cleary show this.

Example: This past summer I did a UOA on the Castrol GTX High Mileage in my Olds minivan. The van had at the time 155,000 miles on it. The oil was in the crankcase for 14 months but only had a little over 4000 miles on it. This van gets used almost exclusively for short trips now just to take my mother to her various doctors' appointments. The UOA showed very low wear metals. TBN was still strong at 6.5. Flashpoint showed a little fuel dilution, which is to be expected given the short trips. But the oxidation and nitration show virtually no sludge precursors. Fourteen months of nothing but short trips where the engine barely got up to operating temp, and this non-synthetic oil performed like a champ. Here's the UOA (Terry Dyson's comments are blurred out because he does not permit public disclosure of his analysis. Only the raw data is shown.)

http://www.oysterquartz.net/BITOG/Olds_van_UOAb.jpg

[army_navy]

"Tribology is the science and technology of friction, lubrication, and wear, derived from the Greek tribo meaning "I rub". Formally defined, it is the science and technology of interacting surfaces in relative motion and all practices related thereto." From Wikipedia, the free encyclopedia

I had to look that one up. I didn't go to a huge school, but I have never seen a class in this offered. Maybe it's a regional thing.

Rub, lubrication, friction,.......sounds like.......
S
E
X
:clap
(I wanna be a tribologist, I wanna be a tribologist):p

[ken01976]

I also like tinkering on the bike, so changing the oil every 3mos/3000 = more quality time with my other half.

[klown]

Hello,

I just was wondering how long i can go safely between oil changes.

Best time to change it is about 10 seconds before your motor locks up :laugh JK, don't know the answer:smoke

[klown]

Why is it that most mechanics always talk about changing oil every 3000 miles. All the cars I've owned in my life get synthetic oil and change oil every 6000 to 7500 miles (depending on the manufacturers recommendations). All these cars last over 200,000 miles. And the engines still run strong when I drive them to the graveyard. Why are mechanics so wrong about this? The people that manufacture the cars know about thier products. :smoke

[ken01976]

The people that manufacture the cars know about thier products. :smoke

And I'm sure its in their best interest to sell you a product that will last forever correct?

[Moved On / My Own Choice]

Why is it that most mechanics always talk about changing oil every 3000 miles. All the cars I've owned in my life get synthetic oil and change oil every 6000 to 7500 miles (depending on the manufacturers recommendations). All these cars last over 200,000 miles. And the engines still run strong when I drive them to the graveyard. Why are mechanics so wrong about this? The people that manufacture the cars know about thier products. :smoke

It's actually not my experience that "most" mechanics say this.

Yes, there are a number of guys who are for a lack of a better term, uneducated and set in their ways. They've been changing oil every 3k miles for 30 years and nothing you say is going to alter that.

But in my experience (and keep in mind that at peak I head about 30-40 techs working for me) MOST of them used synthetics and most of them left the oil in for LONG periods of time.

Of course, I was dealing with a sub-set of techs, serious enthusiasts who could also write. Maybe that has something to do with it. They were the types who were actively seeking further education on the subjects, not just set in their ways and unwilling to change.


K

[Moved On / My Own Choice]

And I'm sure its in their best interest to sell you a product that will last forever correct?


IT certainly behooves them to sell a product that is going to outlast their competition.

[klown]

And I'm sure its in their best interest to sell you a product that will last forever correct?

No but it is in thier interest to keep a good reputation in the community. Reliability is a good sales tool, if they put a reliable product out there the sales would go up. See Toyota Motor Company. They make cars that last forever, but for some reason thier sales have increased, they even outsell Ford and Chrysler here in the US. Sounds like they know what they are doing :smoke

[klown]

IT certainly behooves them to sell a product that is going to outlast their competition.

Exactly! :smoke

[klown]

It's actually not my experience that "most" mechanics say this.

Yes, there are a number of guys who are for a lack of a better term, uneducated and set in their ways. They've been changing oil every 3k miles for 30 years and nothing you say is going to alter that.

But in my experience (and keep in mind that at peak I head about 30-40 techs working for me) MOST of them used synthetics and most of them left the oil in for LONG periods of time.

Of course, I was dealing with a sub-set of techs, serious enthusiasts who could also write. Maybe that has something to do with it. They were the types who were actively seeking further education on the subjects, not just set in their ways and unwilling to change.


K

Well you do have a point there. I usually only talk with the regular type of mechanic. They guy that goes to work everyday etc. Come to think of it. My father in law is an ASE mechanic he also builds high performance drag cars on the side. He tells me 3000 miles. I tell him bullshit! I will do what the manufacturer recommends and I'll use mobile1. He's says your gonna ruin that engine, as I click on 200,000 on my old nissan PU. Once again, same ol banter. :smoke

[ken01976]

Enough of this arguing!!! I shall settle it once and for all! You shall all change oils at 3mos/3000 mile intervals because I said so and I am supreme master mechanic of the cosmos!!! Now shut your pieholes!!!

[klown]

Enough of this arguing!!! I shall settle it once and for all! You shall all change oils at 3mos/3000 mile intervals because I said so and I am supreme master mechanic of the cosmos!!! Now shut your pieholes!!!

Who's argueing? :smoke

[gronk62]

Enough of this arguing!!! I shall settle it once and for all! You shall all change oils at 3mos/3000 mile intervals because I said so and I am supreme master mechanic of the cosmos!!! Now shut your pieholes!!!
:roflblack :roflblack

[Moved On / My Own Choice]

:roflblack :roflblack


I agree Gronk, I gotta admit I like the guy's style!!! :clap

[jwb47]

so when should you really change the oil?

[Moved On / My Own Choice]

so when should you really change the oil?


Before it is no longer protecting the engine.... PERIOD....

[opiewontaylor]

I'd bet that you could safely get a lot more than 5k miles out of a good synthetic. But it's not a bet I'd make with my own bike. At least not my Sportster. (I did own and ride a Suzuki 850 for 65,000 miles, and while I changed the oil every few months, I changed the filter...once. Partly because it was a cartridge arrangement, and a pain in the a**, and partly because I kept hoping it would die so I could ride something that didn't bore the crap out of me....I gave it to my son in law..still runs good...go figure.....

[Ghugly]

It never ceases to amaze me that people will spend their money on what they believe is a fine vehicle, designed and built by competent professionals, and then ignore what the manufacture recommends when it comes to maintenance. :doh There is certainly no reason to get all nervous and anal about following all the manual's instructions to the letter. But, have a little faith in the company that built your bike. When they recommend a certain type and grade of oil and a certain interval between oil changes, have a good reason for deviating from it.

[gronk62]

Just a little story I like to tell people who like to get to get all anally retentive over oil issues.

A few years ago I was a member of a local social Sportster club.

The prez of the club was riding an early nineties (sorry dunno the exact year) Sporty that had clocked up around 150,000 km (93,000miles).

I say "around" because he had a cuppla of speedo related issues where he went for periods of time without a speedo so exact distances are not known.

But anyway, he was the kinda bloke with the attitude, "if it ain't broke, don't fix it".
He also found it a PIA doin' services coz he felt this ate too much into his valuable riding time.

He ran plain old home brand car oil in both his engine and primary for the whole time he owned that bike and only changed it when he flet like it. That mean't sometimes around 10,000km (6000miles).

That engine never gave him a moment of grief until one day he started to hear a dull knockng sound.

He assumed it was his bottom end and so pulled over to the side of the road, stopped the engine and rang someone to come pick him and the bike up.

When he pulled the engine he found the big end bearing was the culprit but was surprised to find very little wear and tear anywhere else.

Not bad for a poorly serviced Sporty running crappy car oil over 150,000km

[TiBaal89]

I manage a Fluid Analysis Laboratory at a midwestern university. We deal mostly with hydraulic oils, but have the capability to analyze engine oils for particle contaminatin by size, count, and weight and do chemical (spectro) analysis of oils, ferrography, photomicrography, etc etc.

One of my coworkers has MORE THAN 20,000 MILES on a change of synthetic in his 1999 ram diesel. He changes the filter every few/several thousand and we frequently sample his oil and analyze it. Its starting to get a high ash content, but chemically the oil is totally fine. :shhhh

The 3,000 mile thing is a load of BS!

If I were an oil company I'd tell you to change it every 3,000 miles - probably I'd say to change it every 100 miles! $$$$$$$$$ :rolleyes:

[Gone]

So, we keep coming back to the fact that today's oils are in a whole 'nother galaxy compared to the "green slime" we had back in the early 60's, when most oil changes were still rated at 3,000 miles. We no longer run oil-bath air filters and today's oil filters actually grab particulates smaller than pieces of sand. And engines are built with exacting tolerances and with much more wear resistant materials. Changing oil and filter every 500-1,000 miles is NOT cheap in the long run, and is just plain wasteful. If a certain engine averages 200,000 miles with 6,000 mile oil and filter changes, that does NOT mean it will average 250,000 miles with 1,000 mile oil and filter changes. 50 year old Navy ships change steam turbine and gearbox oil every few YEARS at their overhauls. The key is keeping it clean, clean, clean, and CLEAN. Truckers (including full-sized diesel pickups) getting 1,000,000 miles on engine life are sure the heck not wasting time and money changing oil every 1,000 miles. They change it when it's time to change it. If YOUR H-D "needs" oil changes every 1,000 miles, you should buy a better built machine and dump the lemon.

[Gone]

Long before these intervals are reached the oil has already turned black.
.

It's blow-by. My little turbo-diesel Ram 50 (Mitsibushi) was used by the previous owner more like a full sized truck (he WORKED IT HARD pulling heavy trailers!!!) and is getting pretty tired at only 142,000 miles. I can change oil and in fifty miles it is pitch black with diesel soot. Still gets 31 mpg. It now gets oil changes only when I feel like it.

[Gone]

I see you swallowed a Dictionary there Gary.:geek

Regardless of who refines it, Dino or synthetic, any oil in a Gas Engine will be subject to the same heating/cooling cycles, water absorption (From moisture) and of course the introduction of blow-by that carries gasoline with it. This mixture under heat can cause sludge to build up, and that carbonize and restrict the flow of oil through the system.
The water and gas break down the lubrication abilities and by 3000 mile or three months, it can get to the point that corrosion and wear can become an Issue.

After 28 years of working on Engines, i am sure I have rebuilt more engines then you have seen.

So, YOUR engine rebuilds wipe out the oil and filter in only 3,000 miles or 3 months? Not sure that applies to factory-built machines.

[ken01976]

Ugh, it seems I must destroy you all...

[klown]

It's blow-by. My little turbo-diesel Ram 50 (Mitsibushi) was used by the previous owner more like a full sized truck (he WORKED IT HARD pulling heavy trailers!!!) and is getting pretty tired at only 142,000 miles. I can change oil and in fifty miles it is pitch black with diesel soot. Still gets 31 mpg. It now gets oil changes only when I feel like it.

You should be glad the the oil is getting black. The detergents in the oil is doing it's job. If that black stuff isn't in the oil then it's in the motor. Just cause the oil is black doesn't mean the oil is broke down. From my understanding, only a chemical lab can tell you if it is in fact broke down. I love oil discussions, cause everybody is usally wrong....except me :smoke

[rvguy]

Enough of this arguing!!! I shall settle it once and for all! You shall all change oils at 3mos/3000 mile intervals because I said so and I am supreme master mechanic of the cosmos!!! Now shut your pieholes!!!

In the military we called that "Taking Charge". Knowing what you're talking about is optional. Making "Timely Decisions" and "Taking Charge" was more important than being correct. Not that you are wrong, but it rings a bell.

[rvguy]

so when should you really change the oil?

Epiphany! Change your oil (any brand mentioned in the lube threads) when you feel like it is the right time. You HAVE to change it when it is gloppy.

[rvguy]

[QUOTE=TiBaal89]I manage a Fluid Analysis Laboratory at a midwestern university. We deal mostly with hydraulic oils, but have the capability to analyze engine oils for particle contaminatin by size, count, and weight and do chemical (spectro) analysis of oils, ferrography, photomicrography, etc etc.

One of my coworkers has MORE THAN 20,000 MILES on a change of synthetic in his 1999 ram diesel. He changes the filter every few/several thousand and we frequently sample his oil and analyze it. Its starting to get a high ash content, but chemically the oil is totally fine. :shhhh

The 3,000 mile thing is a load of BS!

If I were an oil company I'd tell you to change it every 3,000 miles - probably I'd say to change it every 100 miles! $$$$$$$$$ :rol

Yep. I'm trying to kill my 89 toyota pick up with a 22R motor 2bbl. Been over 2 years and 7 to 8k miles. When it dies I'll get a full size truck again. The last oil was the cheapest shyte on the shelf. 91k on the truck. Seriously, I pay attention for the first time to the oil debate because I truly prize my sporty. I have never had a vehicle that I cared about as much. I don't go out and stare at the Grand Marquis....

[Gone]

You should be glad the the oil is getting black. The detergents in the oil is doing it's job. If that black stuff isn't in the oil then it's in the motor. Just cause the oil is black doesn't mean the oil is broke down. From my understanding, only a chemical lab can tell you if it is in fact broke down. I love oil discussions, cause everybody is usally wrong....except me :smoke

Surely the detergents are working at cleaning and keeping it suspended for removal by the filter, though 99% of that soot is too fine to be caught in the filter. I have had the valve cover off and it's still clean inside. What the heck, the truck still pulls the load - even hauling the new Sportster back from Oregon on a 700 mile round trip at it's 31 mpg.

[chrishajer]

P.S. I don't want to start a oil war here, i just want to know how long synthetic oil is good for before it starts breaking down..ect...
You obviously have no idea who you're dealing with here!

Good job... :smoke

--Chris

[Wizzard Of Odds]

2003 Crown Vic police interceptor = every 6K Mobil 1
140,000 trouble free miles, with exception of head gasket leaking oil two months ago (due to age of gasket probaly). Dealer technician said everything looked like new when heads were off.

2002 F350 Superduty Diesel = every 10K Mobil Delvac 1
189,000 trouble free miles

1995 Honda Civic Ex = every 6K Mobil 1
267,000 trouble free miles

1993 Ford E350 Jayco motor home = once a year (about 5K), Mobil 1
110,000 trouble free miles (excluding tranny rebuild in 2004)

1986 Jeep Comanche = once a year
Bought this truck in 1991 with 70,000 miles on it. I've run Mobil 1 in it since I bought it and always changed it once a year, period. This truck is used for plowing snow, it works hard and is on it's third tranny. With 320,000 miles and never an ounce of engine trouble, I'm not changing my habits now.

Bottom line, 3 months and 3,000 miles is to fatten the pockets of mechanics and oil companies, period.

I change the oil and filter in my bike once when the riding season starts, and just before storing it for winter, it's about 8-10K a year. I use Mobil 1 V-Twin, K&N filters, and Mobil 1 75w90 gear lube in the primary. According to oil analysis the oil is fine and ready for more. I only change it as part of my into-storage/out-of-storage routine.

[racerwill]

5000K miles is fine on synth.... check it often and make sure its always full of clean oil.....

Ww

[Malc_F]

I wonder, why would Harley tell us 5000 miles is when to perform an oil change, if it aint right?

Do they want the engines to blow prematurely so we all have to buy new ones quicker? I doubt it, as unreliable short lasting engines would more likely make us say, stuff that I'll get a Jap bike next, or are the MoCo just stupid and dont understand oil at all? I have to wonder! :laugh

[kntalan]

wizzard of odds...thanks for the info. I put alot of miles on my bike(i have put more then 10000 since middle of dec.) i expect to put between 45000 and 55000 a year. living here in the desert i ride year round to work at least 6 days a week. One more question for ya...your bike is a 2003 so you probably have at least 30000 miles on it(based on 8 to 10k a year) have you run the mobil1 75w90 in the primary/trans the whole time and if so have you had any clutch problems..ect.. i just changed my primary oil and went to mobil1 75w90 and was wondering if that is a safe thing to do? I sure do like the smooth shifting with the new oil.

Thanks again..and have a good one...Tom

[Wizzard Of Odds]

wizzard of odds...thanks for the info..............One more question for ya...your bike is a 2003 so you probably have at least 30000 miles on it(based on 8 to 10k a year) have you run the mobil1 75w90 in the primary/trans the whole time and if so have you had any clutch problems..ect.. i just changed my primary oil and went to mobil1 75w90 and was wondering if that is a safe thing to do? I sure do like the smooth shifting with the new oil.

Thanks again..and have a good one...Tom

You're welcome. :)

Yes, my scoot has right at 30K and I've run the M-1 75w90 since the first primary oil change. I've had absolutely zero problems with clutch slippage, nor have I noticed any other ill effects. She still shifts like butter, and I have seen almost none of the "normal" fine metal shavings on the drain plug when I change the primary.

.......Wiz

[ParrotHead]

Change your oil? I can honestly say that I have never, ever, changed my oil in my old bike and at 30+ yrs old it still runs strong. Smokes a little though ...

Of course, it is a 2 stroke :)

[JeePing]

Under your driving condition I think you could go at least 5000 miles between changes. To know for sure, do an oil analysis.

Check out the Used Oil Analysis forum over at BOBISTHEOILGUY. You can see there how people use oil analysis to help them determine just how safely they can extend their oil drains. I personally use the services of Terry Dyson.

x2 that site hase alot of info. Havent done UOA on my bike yet but it;s in plans.