How long does synthetic oil last?

[Timpo]

looks like some of them can last for long time...is it ok for the car though?
would oil still get dirty?

here are some oil change intervals..

AMS OIL: 1 year or 40,000kms(25,000miles)
http://www.amsoil.com/storefront/asl.aspx

Mobile 1: 1 year or 20,000kms
http://www.imperialoil.ca/Canada-Eng...Mobil_1_ep.pdf

[LiquidTurbo]

The 5,000km oil change is an absolute myth, perpetuated by companies like Jiffy Lube. (How else are they going to make their money from you?)

Modern cars and modern oils can go much longer. Just as how car tech has improved since the 70s, so has oil tech. For example, many new cars are equipped with an oil life monitor, which recommend oil changes that are far longer than 5,000km.
It's hard to believe, but the color of the oil has nothing to do with its remaining life and additive package.

One way to check is to do a Used Oil Analysis. (Collect some on the next drain with the free kit you can order from their website), then send it to http://www.blackstone-labs.com.

You'll get a report like this, and you can determine the ideal oil interval for your car.



Amsoil 10W30 - 16,000km. 04 Mazdaspeed MX5, 1.8 turbo


Need more proof? Check out this guy running Amsoil 0w30 with a bypass filter and prelube pump in his S2000. 30,726 miles on the oil! That almost 50,000km!!





Things to realize.
1. Oil color is NOT a good indication of Total Base Number (TBN), or oil life.
2. 5,000km oil change is unnecessary and is a waste of money and oil resources.
3. Oil change interval is heavily dependent on car and driving conditions. If you drive highway frequently you can extend your oil change intervals, because it takes roughly 15-20km for oil to reach full operating temperature. At this temp, you'll be able to burn off the fuel dilution.

Frequent short trips = shorter oil change interval.

By most standards, take an average Corolla or Civic. They can easily go 8,000km on regular conventional oil, even longer on a synthetic fluid.

Personally, I run 12,000km OCI in my RSX with a quality synthetic and sleep well at night. (Confirmed with some used oil analyses). I would have no problem extending out to 16,000km if I had to, the 4,000km is just a nice safety margin.

[Mugen EvOlutioN]

hmmm interesting topic

[thumper]

http://www.bobistheoilguy.com

[CivicTypeRice]

Wonder what Timpo's car looks like.

[AVS_Racing]

lol i change every 3-4xxx km

[shenmecar]

Originally Posted by AVS_Racing

lol i change every 3-4xxx km

really? what oil do you use?

[Mugen EvOlutioN]

Originally Posted by CivicTypeRice

Wonder what Timpo's car looks like.

looks like a fail

[wingies]

can synethetic oil really last that long? I usually change 3000-4000kms too and I use motul in my car. It costs a shitload for an oilchange

[v67gsr]

it can last that long if you don't race the car.

[unit]

im using mobile 1 5w30 synthetic... but i drive short trips all the time to and from work (2min drive or 10min walk but im a lazy mofo)
im prob gonna change it every 8k

[Mugen EvOlutioN]

Originally Posted by v67gsr

it can last that long if you don't race the car.

i think it really depends on your driving habites.

If you are constantly at the track than yes 3000-4000km make sense.


If you are a spirit driver than i think 5000-8000km is fine.


i really wouldnt push it for more than 8000km syn or not, thats just me

An oil change costs $60-70 bux for me with motul, why would i wonna take the risk

[spoon.ek9]

i change the oil when i feel a noticeable difference or see a change in my fuel economy. that's anywhere between 4000-7000km max. plus, fresh oil always feels best for your daily drive

[LiquidTurbo]

Originally Posted by spoon.ek9

i change the oil when i feel a noticeable difference or see a change in my fuel economy. that's anywhere between 4000-7000km max. plus, fresh oil always feels best for your daily drive

What oil do you fill with? You can actually a notice a difference in fuel economy? How much?

[Leopold Stotch]

personally. it' shard for me to go 5k on an oil change, my car already burns a bit of oil and the oil darkens quite quickly and easily. i do drive quite spiritedly.

i'm using cheaper oil. Mobil 1, so i change it whenver usually.

[v67gsr]

Originally Posted by Mugen EvOlutioN

i think it really depends on your driving habites.

If you are constantly at the track than yes 3000-4000km make sense.


If you are a spirit driver than i think 5000-8000km is fine.


i really wouldnt push it for more than 8000km syn or not, thats just me

An oil change costs $60-70 bux for me with motul, why would i wonna take the risk

3000~4000 is over due if you track the car. I change it after every track day even though it is 300V. I run some cheaper products like 4100 for street, switch to 300V for track, then back to 4100 right after track day. I burn oil $ fast during the summer............

[Mugen EvOlutioN]

Originally Posted by LiquidTurbo

What oil do you fill with? You can actually a notice a difference in fuel economy? How much?

you actually notice a difference between using old oil and new oil???

Originally Posted by v67gsr

3000~4000 is over due if you track the car. I change it after every track day even though it is 300V. I run some cheaper products like 4100 for street, switch to 300V for track, then back to 4100 right after track day. I burn oil $ fast during the summer............

300V is balllinggggggggg


8100 for me only
cant afford that shit, well for DD i guess its more than enough since i dont track my car

[hirevtuner]

i change the oil every 5K with mobil 1 5w30 and add STP fuel injector cleaner with a full tank of gas and it feels lost power got restored and i drive mainly short trips

[v67gsr]

Originally Posted by Mugen EvOlutioN

300V is balllinggggggggg


8100 for me only
cant afford that shit, well for DD i guess its more than enough since i dont track my car

I have to agree more less. But 300V do allow me to be lazy sometime if the track event is close to each other. I will just run the same tank in the 2nd event.

BTW, 300V for cars are expensive. However, 300V for 4 stroke motorcycle is cheap (like 2/5 the cost of 300V for car). We ran it and everything is just fine (oil temp and oil pressure). And it comes in neon yellow too !!!

[q0192837465]

Originally Posted by hirevtuner

i change the oil every 5K with mobil 1 5w30 and add STP fuel injector cleaner with a full tank of gas and it feels lost power got restored and i drive mainly short trips

I think that's a bit too frequent. Those oil can last for at least 15,000km. U'r wasting money tbh

Gotta realize that fresh oil is NOT always the best. Generally, it takes oil ~1000-2000km to "break in" so to speak. If u'r changing so frequently, the time ur engine is running "optimal" oil is less than say someone changing every 10,000km

[LiquidTurbo]

Originally Posted by q0192837465

Generally, it takes oil ~1000-2000km to "break in" so to speak.

No offense, but you have no idea what you're talking about and just made that statement up completely.

[taylor192]

Thank you to LiquidTurbo for posting the correct response!

Blackstone labs costs ~$30 CND including the shipping and you get a good estimate of how long you can run your oil. They send you the kit for free (I have one), you ship it back with payment, they email you results. So easy!

Considering synthetic oil costs ~$10/L, this $30 test can pay for itself.

The test includes other results, like if you have coolant in your oil (HG leak), or metal particles (unusual wear, and type of metal can even pinpoint what is wearing), ... so the test should be part of regular maintenance to find out how your engine is doing.

I've been doing 15K changes on my C-class, and am considering going down to 10K changes cause of the additional city driving I do now living in Vancouver. Yet the Blackstone test will tell me exactly what to do, and will be well worth the $30.

[q0192837465]

Originally Posted by LiquidTurbo

No offense, but you have no idea what you're talking about and just made that statement up completely.

Not exactly, I read it @ e46fanatics. People are arguing that changing oil every 3000km is the best thing to do. Then someone found that oil companis have done studies on it and conclude that it takes time for fresh oil to bind to engine parts and create a "protective layer". That protective layer is gone when u do an oil change. So if u change oil too often, the protective layer will not have a chance to establish and result in more wear to the engine. It has been a while but I'll try to find that article.

Edit: There it is

Mobil 1 currently enjoys the distinction of being the only readily available true PAO synthetic motor oil. You can get the stuff at Wal-Mart for Pete's sake! Perhaps because of its wide availability and comparatively low price, we entered this test with both hope and skepticism: hope that it would do well and vindicate millions of M1 users, and skepticism that it would pull it off. We were expecting it to look pretty beat up by 8,000 miles or so; to say we missed the mark would be polite understatement. Mobil 1 really delivered: 18,000 miles later, it was showing its age but was still hard at work protecting the engine.

As our first phase of the Synthetic Oil Life Study, it was as much a learning experience for the process as it was for the results. We changed some things along the way -- moved the filter change from a mileage-based rule to a performance-based rule, altered the tolerable limits for viscosity, learned a lot about TBN, and a few other things -- which set precedents for the remainder of the study.

But the big question is, what have we learned so far? Here are a few points to ponder, based on our experience with the Mobil 1 phase.

Getting just one oil analysis only tells a tiny piece of the picture. It essentially would serve only as a pass/fail mechanism; without a trend to monitor, the most interesting parts of the analysis would be impossible to see.

Total base number is a moving target. There are multiple methods for testing it, which makes comparisons between laboratories worthless, and none of the methods have repeatability rates worth getting excited about. While TBN is worth considering as part of the larger picture, as a singular measure it is too flawed to rely on.

Engine wear actually decreases as oil ages. This has also been substantiated in testing conducted by Ford Motor Co. and ConocoPhillips, and reported in SAE Technical Paper 2003-01-3119. What this means is that compulsive oil changers are actually causing more engine wear than the people who let their engine's oil get some age on it.

Topping up the crankcase is a critical component of extended oil change intervals, and frequent filter changes are most likely the key to extreme-length intervals. The cumulative effect of even minor top-ups, let alone a filter change, substantially increases the longevity of the oil.

Based on the results we've got here, we'd recommend 8,000 miles between oil changes on an engine that uses no oil at all, perhaps 10,000 miles on an engine that uses some oil, and 15,000 miles or beyond with a filter change every 5,000 miles. This, of course, isn't any kind of guarantee, and you must evaluate for yourself what your engine requires. One thing we're pretty sure about though: 3,000-mile intervals is a huge waste of resources.

Sauce: http://neptune.spacebears.com/cars/stories/mobil1.html

[LiquidTurbo]

Originally Posted by q0192837465

Not exactly, I read it @ e46fanatics. People are arguing that changing oil every 3000km is the best thing to do. Then someone found that oil companis have done studies on it and conclude that it takes time for fresh oil to bind to engine parts and create a "protective layer". That protective layer is gone when u do an oil change. So if u change oil too often, the protective layer will not have a chance to establish and result in more wear to the engine. It has been a while but I'll try to find that article.

Edit: That actual article was deleted, but the summary is here (quoted straight out of e46fanatics from 2004)

I actually read that study before, and it's somewhat controversial in its conclusion.

The first things that came to mind was: More engine wear? Is this opinion based solely on interpretation of a single-pass UOA's from this particular test or do more test results & dimensional data support this theory?

You'll find that that there was no tear-downs being done, which is the ONLY way to measure engine wear (with a micrometer). You cannot tell engine wear from the condition of the oil. Single pass UOA's are only a good indication of oil life, additive package remaining, fuel dilution, and whether or not you have contaminants leaking into your oil, like coolant.

Edit:
I seem to remember that they cleaned the parts between oil changes, effectively removing any protective layer that the oil had put in place. The fresh oil had to re-establish an anti-wear layer. If that's the case, of course wear will be higher with new oil. The study may have no relevance at all to real world oil changes where the protective layer is not disturbed.

[Rich Sandor]

The more additives in the oil, the faster it'll break down. Try to stick with an oil with a low viscosity spread, like 10w30, or 20w50, or 0w10. Avoid 0w50 'all purpose' oils, as the friction inhibitors break down quickly and revert the oil back to it's base weight, while leaving behind contaminants. (unless you are going to be changing the oil very frequently)

In a Vancouver Daily Driver, you can stick with 10w30, because it never gets below -10 or over +30, and you won't be driving the car hard enough to benefit from a w50 oil.

But I track my car a lot, and take it south as well, so I need a 15w50 oil for those track days, but in the winter, that oil is too thick and the car idles poorly when cold. So I either park the car, or change the oil to something that warms up faster in cold weather.

I go for about 10,000-15,000km on the oil, because I know I'm using the right oil for my application. I could probably run it longer, but at around 15,000 the oil is usually solid, solid back, and at that point I just feel better about changing it.

3000km is too soon. 3000 MILES maybe.

FYI, Ford used to recommend oil changes every 5000km.. now, the OWNERS MANUALS recommend 12,000km oil changes. That should speak for itself as far as how much better oils and engine have become.