How long does synthetic oil last?

[Timpo]

Originally Posted by Rich Sandor

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.

Is that conventional oil or synthetic?

My friend's Suzuki Sidekick's owner's manual recommends oil change every 15,000kms. (non-synthetic, conventional oil)

[Rich Sandor]

i'm pretty sure it's both, actually.

[GordonTse]

i change my oil every 3k km's. use conventional 5w30 from work which is no cost to me. i don't change filter everytime. short trips to work 6-7mins everyday. spirited drives once in ahilwe eg vtaaaaak :P was thinking of switching to synthetic but no point when i got free oil from work. but soon i'll go synthetic for my manual trans.

[Death2Theft]

What about time intervals where they say u should change your oil once a year even if u never hit 5k.

[hk20000]

Hmmmm I should go top up my oil and change a filter while keeping the current oil then for the next 5000km thing. It just happens that my timing belt needs changing 5000km after the last oil change.

[suzuka84]

oil is such a touchy subject. How many of you guys go out of your way to find German Castrol?

For me, it's Costco synthetic as it's cheap and readily available.

[eFx[A2C]]

It's not THAT hard to find GC...Ctire and Walmart has it.

[wnderinguy]

http://dodgeownerclub.hqforums.com/2...b377ba52f67518

[spoon.ek9]

Originally Posted by LiquidTurbo

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

for the EK i'm using Eneos 5w30 synthetic
for the EF i'm using conventional cheap shit from petro canada

the fuel economy drops 50-60km/tank or more when the oil is near changing (for my personal preference). the difference in feel is there too (no one can deny how smooth the engine feels after an oil change). the engines struggle to build rpms when the oil is near black, so that's why i change it.

[shenmecar]

^

where do you buy Eneos?

[Mugen EvOlutioN]

do any of you uses fuel injector cleaner?


i know engine flush is bad...but..?

[illicitstylz]

Is there a relationship between the age of the car and frequency of oil changes or oil type? ( Synthetic or conventional)
Posted via RS Mobile

[roastpuff]

Originally Posted by shenmecar

^

where do you buy Eneos?

Only place I know locally that stocks it is Rev Competition in Richmond.

http://www.revcompetition.com/shop/i...6hm9edn1bs4c44

[hk20000]

Originally Posted by Mugen EvOlutioN

do any of you uses fuel injector cleaner?


i know engine flush is bad...but..?

fuel injector cleaner is known to gum the shit out of the system....

[spoon.ek9]

Originally Posted by shenmecar

^

where do you buy Eneos?

i get it from either SR Autogroup or Sky Auto. both are on the same street in Richmond.

[thumper]

Originally Posted by GordonTse

i change my oil every 3k km's. use conventional 5w30 from work which is no cost to me. i don't change filter everytime. short trips to work 6-7mins everyday. spirited drives once in ahilwe eg vtaaaaak :P was thinking of switching to synthetic but no point when i got free oil from work. but soon i'll go synthetic for my manual trans.

do you also change the filter as well?

i ask this because i know people who will change the oil only after 3k, but leave the original filter until the next oil change (6k).

[thumper]

Originally Posted by Death2Theft

What about time intervals where they say u should change your oil once a year even if u never hit 5k.

i've been told at least twice a year (every 6 months)?

[hk20000]

Mercedes recommend 1ce a year or 12000km whichever comes first. My garage queen usually the former.

[Mugen EvOlutioN]

^


yes but i spoke to one of the mechanic, one of the BMW had to be towed to the shop due to sludge build up. Not changing the oil frequently causes the engine to build up bunch of craps

[hk20000]

Originally Posted by Mugen EvOlutioN

^


yes but i spoke to one of the mechanic, one of the BMW had to be towed to the shop due to sludge build up. Not changing the oil frequently causes the engine to build up bunch of craps

but i remember that other story on the internets that "sludge killed my engine" happened to a 3 series that didn't get one oil change during its 60k km service life.

So the oil kept the engine running for at least 50k?

[tewee]

Originally Posted by hk20000

fuel injector cleaner is known to gum the shit out of the system....

fuel injector cleaner that u buy off the shelf at stores at canadian tire don't do much good. fuel injector flushing (industrial cleaners) should be a maintenance procedure for your car (ie. once a year). gasoline residue (varnish) sticks on the tip of the injector causing abnormal spray patterns or causes leaky injectors. fuel dryers are good too, as they remove water from inside the gas tank. seeing as we live in a high humidity area, we should add fuel dryer into our gas tanks accordingly.

[AVS_Racing]

Originally Posted by shenmecar

really? what oil do you use?

i use Eneos i can hook u up if u want

[RabidRat]

Originally Posted by 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.

that was extremely informative, thanks for that!

[LiquidTurbo]

No problem dude.

Just pains me to see people running 3,000km/3month oil change routine without really thinking about it. It's like changing your underwear 3x a day because someone told you to.

Waste of precious oil resources (and money too!)
If anyone decides to go do a Used Oil Analysis (UOA), things to note are the viscosity (make sure the oil hasn't sheared out of its range limit.)


Refer to the SAE (Society of Automotive Engineers) chart below, for viscosity limits for oil weights. The first column denotes weights. For example, the 30, in 5w30. The 40, such as in 10w40. This is a chart for 100 degrees C temperature. (As you might know, viscosity changes with temperature. SAE likes to use 40C and 100C as datum temperatures for oil viscosties.)



For example

looking at the S2000's UOA in the above post, we see that the viscosity at 100C is at 11.22 centistokes.

According to SAE regulations this oil, amazingly after 50,000km still has the viscosity properties of a 30 weight oil. There are some UOAs that show a drop on operating cST below 9. This means the oil has 'sheared out of viscosity'. It's a common problem for an oil that's been left in too long. Cars with timing chains instead of timing belts also tend to shear oil more easily. Sometimes 5w30 oils shear to 5w20 levels. That's not acceptable for say, a turbo application like the RDX, which calls for a synthetic 5w30 oil that meets the strict HTO-06 spec.

Another variable to note is the Total Base Number (TBN). Most modern oils start at TBN number of around 7-10, Amsoil even 12. The number then decreases non-linearly to 0. A TBN of 1 is considered too spent. In the example of the Miata above, it was rated a 3.3. It probably could have gone a couple thousand more KMs. The higher quality oils, such as the ones from a Group IV or a Group V basestock will tend to have higher TBN numbers.

Quick 101 on Oil: Oils are made up of Basestocks and Additive Packages. Basestock are the "meat" of the oil, where the additive package give the basestock different desirable properties by adding components, such as detergents, friction modifiers, rust inhibitors, anti-foam agents, pour point depressants, dispersants, and anti-oxidizing compounds, just to name a few. The additive package ranges anywhere from 1% to 20% of the oil volume.

Basestock Groups:
Group I - Mineral oils - cheap, outdated conventional oils may fall into this category.
Group II - Most modern conventional oils (dino) fall under this category.
Group III - Made from a process called Severe Hydrocracking or Severe Hydroprocessing a Group II basestock. Essentially super-refining the Grp II basestock to nearly have Group IV properties to simulate synthetic oil bases.
Group IV - PAO or Polyalphaoloefins. Made from men in laboratory coats. The truly synthetic basestock.
Group V - Made up of Esters and polyolesters. Another creation of men in laboratory coats. Group V isn't usually used a a pure basestock, but mixed with other ones to give it more desirable properties.

Hint: Mobil1 5w30, Castrol Syntec (Except German Castrol), Pennzoil Platinum all fall under Group III category. (They technically aren't TRUE synthetics, but are allowed to be marketed as such) Only Amsoil SSO/ASM and German Castrol are known to be of Group IV basestock (completely synthetic). Some other grades of Mobil1 such as 0w20 and their 15w50 are speculated to be synthetic blends, containing only some PAO.



So anyway, back to the UOA, all the other metals test show different stories such as air filtration problems (a high Silicon number would show).

The 3rd thing to look out for in a UOA is the fuel percentage. A high percentage of fuel in the oil (roughly >3% (due to the blowby from the piston rings) is a good indicator that the oil will need to be changed more frequently than a non-fuel diluter. A common example of a fuel-dilutor engine is the 3.0L V6 in the newer Accords.

Lastly, the other things to note is the insolubles number. A high insolubles number means the oil filter is not doing it's job well. Contrary to popular belief, the oil filter doesn't "clean" the oil in the sense that it turns the color from black, back to the original golden brown color (or purple in Royal Purple's case, or Green, in German Castrol). It's job is to filter out insoluble particulates that the oil itself cannot encapsulate(dissolve and hold in a suspension).


Just as there is no best car, there is no such thing as a 'best' oil.

Hearing about people putting Motul 300V Synthetic Oil in their 1.5L stock Civic (but it has a WING! and VTAAK!) which is used to get groceries is rather pathetic to point of .

The ideal oil for your car depends on many factors, such as:

1. What kind of vehicle you have
2. What your owner's manual says -- not just viscosity, but certifications (look for acronyms like API SM, ILSAC GF-4, etc.) and their recommended change intervals as well
3. Where you live, the seasonal temperature change.
4. How you drive (easy? hard? fast? slow?)
5. What your daily drive is like (short trips? long trips? city? highway?)
6. Whether your car has any known problems
7. Whether you want synthetic vs. conventional
8. How long you'd like to go between oil changes

Going for a pricey synthetic may not necessarily be the smartest choice depending on the variables listed above.

[LiquidTurbo]

My personal favorite oil.