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mark77s

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Posts posted by mark77s

    The Goods On Oils

    in General Maintenance

    Posted

    I agree with the first paragraph but not the second.

    Why higher temps for a worn engine? I mean are you saying that you expect your engine to run hotter as it gets more warn and will therefore need a oil with a higher number at the end (forget the technical term for this :) )?

    I've been told to keep the numbers closer together, so 0w30 is good is you are not hitting temps like 110degrees (or was it a bit less)? At that point the oil is too thin and you should be using something w40....or even higher if you are a track car...

    Regards,

    Gareth

    My understanding of increasing the oil viscosity is to maintain the pressure of the oil. Each car has an ideal pressure @ x rpm, in order to maintain this pressure a thicker oil is used to achieve this. I see alot of people using a xw-40 or thicker oil for GTR's even though the manual states a 7.5w-30 oil. Same goes for other sites, skylines or not.

    I have also heard to keep the oils numbers closer together. Oils which span a large range i.e 0w-50 have alot more additives in it to make it that type of oil and as time goes on these additives break down and you will no longer have a 0w-50 oil. It may be a 5w-50 or 10w-50 for sythetic oils but if its a mineral oil the 50 drops to say 40. So if you change your oil often it should be ok. Only real way of knowing is to get your oil tested at a lab to see how much your oil has broken down over time.

    The Goods On Oils

    in General Maintenance

    Posted

    Depends on how cold it gets, it's not too thick really as 10w is spec (ASTM D-5293) to flow at -25'c. A good Synthetic will have a lower cP then a mineral though.

    The cold doesnt really matter unless its below zero and even lower as most oils can handle the extreme cold and maintain there properties to a certain point.

    A 10w-40 oil when the car is started in the morning is 10w when cold which equates to say the viscosity of 90Cs, (The thickness of moving oil is measured in centiStokes or cS) when it its at operating temperature (the last digit "40") ideally it equates to 10Cs. So at 10Cs there is minmal wear to the engine and provides the engine with max protection. Whereas 90Cs is thick and will wear the engine until it reaches operating temp. A 5w-40 will be 70Cs at startup and still be 10Cs at operating temps. A 0w-40 will be say 50Cs when cold and 10Cs at operating temps. All oils are still too thick at startup but wouldnt it make sense to go for the 0w or 5w cause it isnt as thick as a 10w or 15w oil when cold?? The majority of engine wear does occur at startup when the oil has thickened overnight. I would only use a 15w-xx or 20w-xx if it was a very hot day at the track.

    I agree with Gohan 0w or 5w and for a worn engine 40 eg. 0w-40, 5w-40. In 10-20years i would go up to 0w-50 or 5w-50

    The Goods On Oils

    in General Maintenance

    Posted

    Mmmmm ic, was in contact with the comnay who brings he REPSOL oil to australia today, (Iknow they are very good quality oil) unfortunately its not available over the counter for dy to day ppl, only registered mechanic shop can buy it from them, but the guy from sales team advised that he will try his best to get me a place if there any in NSW which I can get it off the counter, so far no good news.

    I was using repsol 5w-40 when I gave my car to service every six months to mech in five dock, charge $250 and I could seeonly thing they do is changing oil thats all, doggy ppl, so wanna do it my self...

    if I cant get the repsol full syn 5w-40 then thinking of going for Motul 300v 5w-40 or Penrite 5w-40?

    some say since the car is old i should be using a bit thicker oil like 15w-40 etc which confuce me...........

    well full synth is tha way to go for NON-TUrbo cars as well then hey......... :)

    Cheers

    SkyKC, All manufacturers I have seen are specifying 0W-XX or 5W-XX oils now. Honda, Ferrari, Ford, Mercedes, Porsche, and others specify a 0 or 5W-XX oil to mention a few. These are appropriate for all engines of all ages of all levels of wear. This second number is the only thing that may change with an older, lose or worn engine. I have heard that oils labeled for RACING ONLY is not usable for every day driving. Often these have more additives that are toxic to your catalytic converters and the environment. These oils generally do not have detergents. These are very important for your engine unless you plan on taking it apart every few weeks and cleaning every single surface. Motul 300V says its for racing cars not sure if its for RACING ONLY. Try German Castrol 5w-40 you can buy it from Harold from Performancelub (i think thats the name) its a good oil. I have recently put German Castrol 0w-30 in my WRX and it seems to love it and the engine is so quite. I guess you have to experiment to find the correct oil then stick with it.

    If your still confused and feel like learning more on oils either goto http://63.240.161.99/motoroil/index.html (HIGHLY RECOMMEND reading this although a little long but you can skip some chapters)

    http://www.bobistheoilguy.com

    The Goods On Oils

    in General Maintenance

    Posted

    I can undwerstand after readiing all these that Fullsynthetic is the way to go for TURBO engine, how about RB25 NON-TURBO? my GTS4 non-turbo (RB25DE) has done 112 000KM, and thinking wich oil to go for, at the moment using elf 15w-something but idleing not that good.

    Is full synthetic good for NON-Turbo cars? (Given that Money is not an issue ) if so which viscosity 5w-30? 5w-40? etc

    Cheers

    When the car shutsdown the sythetic type oil thickens less than mineral based oils of the same weight and therefore there is less stress on the engine at startup (better lubrication), where a high percentage of engine wear occurs. Whether it’s a turbo or non turbo car it really doesn’t matter all that much. Stick with the latest API/SAE ratings of SL & SM as these are a far better oil than the SJ oil that was recommended in the early 90’s. I would also recommend a 0w-40 or 5w-40 oil. I still don’t get why people insist on putting in a 10w-40, 15w-40 etc in a street driven car as these oils are way to thick to provide proper lubrication at startup. Hence why you can now buy 0w oils as the oil companies have realised that the lower the weight at startup is way better for the engine. Even though a 0w is still too thick for an engine at startup but its thinner and provides better lubrication than a 5w,10w,20w etc. Since its an old car i would go for a 0w-40 or 5w-40 if the manufacture recommends a x-30 oil.

    What Oils/oil Filter

    in General Maintenance

    Posted

    Running German Castrol 5w-40 in an R32 GTR, filter oem

    Still trying to figure out why people use a 10-20w in thier cars unless your racing? The most engine damage is done starting the engine cold the lower the first digit the better. A 10w oil is thicker at startup compared to a 0w or 5w. No oil gives total lubrication when cold but hence the oil companies are leaning towards lower first digit oils now e.g 0w. The second number is the viscosity of the oil at operating temps, 40 is good for skylines unless racing in hot conditions. Also its better to use an API rating of SL or SM rather than SJ which is stated in the oem manual as the SL and SM are a better oil using the latest technology and wernt around when SJ was popular. You will get better results in regards to maximum cam plus lifter wear, sludge build up, high temperature volatility amongst alot of other things with an API rating of SL or SM over SJ. SM should be better than SL

    Motor oil that is labeled for RACING ONLY is not usable for every day driving. Often these have more additives that are toxic to your catalytic converters and the environment. These oils generally do not have detergents. Use these oils if you plan on taking your engine apart and cleaning it every few weeks

    This site is very helpul explaining oils

    http://63.240.161.99/motoroil/index.html

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