SilverRSXJezus

Except there probably won't ever be an instance of someone able to run 15k miles on on oil change....unless you're saying that the person is a willing cheapskate and feels like changing it later than when he probably should.


There are plenty of ignorant people out there, so it's not always in their best interest to do anything they want without some basic information.

G37xS

Porsche 987S and BMW M3 recommend to change oil (synthetic only) in 15K. But I do it every 7.5K. Also, they use about 7 to 8 liters per change.

Mayu

Before you read - I DO NOT...
1) work in the car biz
2) work for an oil company
3) have an engineering degree
4) have ANYTHING to gain from sharing my research with you...
5) enjoy long posts, but find I do this on Fridays at work... Sorry.

FYI... I have a Comp Sci degree and work for a marketing firm... anywho...

...I have been researching oils for the last month since my G37S has been in storage for the winter and I want to start using "100% SYNTHETIC" this spring - NOT to be confused with "FULL SYNTHETIC."

Difference?

There are only 3 oils out there (that I know of/can find locally) that are REAL Synthetic and MAN-made from Ester. These are Lucas (from Great Britain), Amsoil (from the US) and Motul (Australia/France).

Other oils (Mobil 1 Sythetic, Quaker State Sythetic, etc) are FULL Synthetic meaning, they are VERY highly refined mineral oils. Refined to the point they have higher viscosity and lubricity than their 'conventional' bretheren. This extra refining is said to be enough human intervention to "Consider" it a 'Synthetic'. Now the marketing gurus come in and sponser wonderful Nascar teams to advertise their 'synthetic' oil.

So what?

Mineral oils, when refined enough will imrove as mentioned above. HOWEVER, no matter how much you refine them, they will NEVER spontaneously create the chemical properties found in ester based oils. The properties I talk of are what helps esters BOND to metal. Yes, ester will infuse into the meteal and create a continuous film of oil minimizing 'dry' starts - the leading contributor of engine wear. Furthermore, these Ester based, 100% synthetics, have MUCH higher 'shear' resistance and 'climbing' properties than these refined minerals. In addition to this extra protection, they do not burn in the combustion chambers allowing for longer change intervals - BMWs 15,000 mile service schedule for example.

Do not use oil additives. Some (like the Lucas Synthetic Oil Additive) are simply 100% synthetic oils you add to your crappy mineral oil to give it some of the properties of a ester synthetic at 20X the cost. Others can be really harmful as seen with ZMax.

To be safe do this:

1) Use mineral oils for the first 10k miles/km - break-in period for engine.
2) Do not "Think" or "feel" for what your car needs - IT NEEDS regular changes.
3) Once ready to move to 100% Synthetic, do an engine flush (Motul sells one) before the first change to get rid of as much of the old mineral oil as possible.
4) Maitain your regular service schedule based on your driving style - you are only helping protect your investment/baby/best looking thing about you - kidding
5) Never go back to mineral.

FYI - those of you with high mileage engines that have been on minerals the entire life should NEVER be switched to 100% synthetic as these oils love to creep on metal - remember they infuse into it. This means, an old engine with already weak seals will have oil creep out of it. This will not happen with FULL synthetics (Mobil1) - as these do not 'creep' or 'infuse' into metal. (not sure what they "SuperSyn" technology in Mobil1 is though - could be a 100% synthetic oil added into the highly refined mineral to get some oil to metal infusion)

So what is the best oil?

Any ester based 100% synthetic will do. But only Motul has an oil made from Complex Ester with better properties. At this point, you are trying to decide between the best and you cant go wrong.

DISCLAIMER: I have not switched yet. I have 6L of Motul 300V 5W30, one bottle of Motul Engine Flush and one bottle of Motul Fuel System Cleaner waiting. I am going to the dealership tomorrow for a regular oil change, then I am booking an appointment with a highly respected local garage (RT Motorsports for any Torontonians on this forum - ask for Rick) to have the Engine Flush and Synthetic switch done.

I will come back to this thread and update. My camera is broken so I cant take any pics of the oil containers and the flushes. I must say, the containers are pretty damn cool looking (yeah, I am a grease monkey and a techie, but I am in marketing). The finacee was jealous that I was staring at the containers so much - she asked if 'we' wanted to be alone. I said... "Yes!"

sorry about the long post - but this is an important subject and group of cars!!

notalk

Keep researching. You have a way to go.

Mayu

Funny. Almost as useful a comment as your "rtfm" to the OP'er.

If you have nothing useful to say, perhaps because you know nothing, please log off. The rest of us are all trying to learn something here.

But, thanks, I plan on continuing my research despite your useless feedback and hope to help others out on this forum.

Good luck to you!

SilverRSXJezus

Thanks for your post...it confirms most of what I've read as well with regards to the differences between "100%" ester synthetic oil, "full" synthetic, and conventional mineral.

G_Thang

WOW.. That is the first post on this site that I've learned something from (not to knock anyone or boast myself). To the one that said change it when you feel it needs it! What kind of systematic answer is that. Oil serves three purposes:

1) Lubricate
2) Cool
3) Disperse soot from combustion

Engineers design with a "factor of safety" which is a way to protect the consumer. Ex. You buy a chain with a rated 3000lb max capacity, but material properties will actually allow the chain to withstand a 4500lb load. Engine oil is no different. I follow the owners manual on oil change intervals to an extent, but I know the signs of oil thats broken down. If you look at your oil after 3500 miles and its still partially clear, its not saturated with "soot". This "soot" (from combustion) is what causes oil to turn black. When your engine oil is full of soot is cant disperse the soot anymore and has reached the end of its life. Viscosity can also break down under elevated temps and lead to premature life if you drive hard or track the car. In the end it depends on the driving style of the driver and environment, which is why they give a "general" interval for everyone to follow... which protects them, and the engine.

Mayu

Thanks SilverRSX and G_Thang - I thought I was finally getting there with the information. Good to know you guys have found the same information as I did.


Cheers. and here is the motul oil I was referring to. I asked my Infiniti Service Manager his thoughts on this oil and all he had to say was "its the best oil you can get."

todd92

You have a ways to go.

First, your entire distinction between 'real' 'full' 'man-made' synthetics is just plain wrong. There are 3 kinds, Group 5 (made from esters), Group 4 (made from polyalphaolefins) and Group 3 (highly refined petroleum). They are ALL synthetics. Each is better is some respects and there is no clear benefit of one over the others, but the marketing hype to lead you to believe otherwise is relentless. What matters is how the oil holds up in use, and that can only by known by finding and using it to it's service limit using oil analysis.

The bonding to metal is nonsense.

BMW recommends oils for the 15,000 oil change intervals. Currently only Group 3 and Group 4 oils are on the approval list. So much for esters here.

Stay away from additives. You are 100% correct here.

No need to wait to use synthetic for any period. Many cars (BMW, Porsche, MB, VW, Corvette) come with synthetic as initial fill.

Of course you need regular oil changes. That is somewhere between 7500 and 15000 miles with a synthetic, depending on your driving conditions.

NEVER use an engine flush.

Protecting your investment? Since when is a rapidly depreciating vehicle considered an 'investment'? Just do regular maintenance. It's a machine, not a 'baby'.

You can switch back and forth between mineral and synthetic, and even mix them together, with no problems.

There is no BEST oil. There is only BEST marketing, which your post shows that you have succumbed to.

G_Thang

Not all "investments" appreciate. Seen the DOW lately? A car is an investment in that you take your hard earned money (or banks) and purchase a tangible good. Would you say a house isn't an investment? Absolutely not, but have home prices increased in value in the past several months?

todd92

An investment is purchased with the expectation it will appreciate. Vehicles (except the tiny collectible segment) have never fit that definition.

G_Thang

Its relative. Economist call homes and machines investments, while financial economist call investments financial assetts. I tend to use common sense. If you dont view your car as an investment, you should sell it and try hitch hiking, riding a bike, taking the bus, etc. for transportation. A car is an investment in your mobility. You will surely waste more enegry and money takng public transportation. Remember, time is money too. You cant get so wrapped around the axle. Step back and look at the whole picture. It would cost me $50/day to take a taxi to and from work. I live 70 miles from work, so a bicycle is out the window.

Thrillhouse

You're just getting caught up in semantics at this point. Whether a car can be considered an investment or not isn't important to the discussion at hand.

todd92 made some good points. There is no One True Oil out there, but there is a vast number of perfectly good ones. It's more important that you get the correct weight of oil and change it on time, than it is to use some fancy expensive boutique oil.

delfin2003

wow, thank you so much buds, it's like OIL 101 here

notalk

The original poster wanted to know how often to change his oil. The "official" answer is in his owner's manual. Please tell me why suggesting the original poster read his manual to get the answer wasn't a useful response?

I didn't give you detailed responses because I hoped todd92 would spend the time to point out the fallacies in your post. Thankfully, he did.

Since you missed the biggest selling polyol ester base stock oil, RedLine, I believed you really had not performed the research you believed you had performed.

Come on, you read a few web sites on the internet and you believe that substitutes for years of experience working with petroleum/oil engineers?

The basis for your learning should be published white papers. Otherwise, you are just regurgitating misinformation passed along on the internet.