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Engine Oil Myth Or Fact?

LatinR33

By LatinR33,
in General Automotive Discussion

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SS8_Gohan Grand Master

SS8_Gohan

Posted
Posted

http://63.240.161.99/motoroil/index.html

from other thread.

I just read the first page. I may have read it wrong, but almost seems as if it's very hard to go too thin, that's not that problem. Goes as thin as possible

xtra.5 Enthusiast

xtra.5

Posted
Posted
http://63.240.161.99/motoroil/index.html

from other thread.

I just read the first page. I may have read it wrong, but almost seems as if it's very hard to go too thin, that's not that problem. Goes as thin as possible

I just read that link, and I agree. Thinner is better, for daily street use anyway.

I use fully synthethic in my RB25, and have since the day i got it

Chris_R33GTSt Proficient

Chris_R33GTSt

Posted
Posted

I Use Kendall full mineral oil in my R33. 20W50 in Summer and 10W40 in Winter. The stuff is absolutely fantastic. It basically stops engine wear and has the same if not better properties as synthetic oil including burn point.

Beer Baron Grand Master

Beer Baron

Posted
Posted
Hey how are we all?? Just wondering I was speaking to a mechanic and was advised that full synthetic oil may be abit too thin for my R33 and for security has said that semi synthetic would be a safe choice. What do you guys think??

not true. oil thickness is not directly affected by whether it's synthetic or not. my advice is go for a good full synthetic. something in 10W40 should be fine. personally I like motul chrono 300V, but it's pretty pricey. there may be other options nearly as good, but for much less $$.

Beer Baron Grand Master

Beer Baron

Posted
Posted

10W60 is not neccisarily a good choice. ideally you want the two weights as close together as possible. because to make an oil have the property of a 10 weight at one temp and a 60 weight at another requires a lot of additives. even a 10W40 has the hot weight 4 times the cold. 6 times is too much imo. 3 times or less is desirable. but I live with the 10W40 as it's a synthetic ester base.

Kinks Grand Master

Kinks

Posted
Posted

Get a new mechanic, he has no clue about engines.

Beer Baron's rule of thumb is true for mineral oils at least, as they do have a natural tendency to thin out when hot, so additives are added to reduce this. The wider the vis range the more additives (which break down over time, meaning your vis changes).

Synthetic oils don't thin as much, and don't require as much additive.

Only go for a 50 or 60 weight when racing. It's much too thick for the street.

5W-30 or 0W-30 fully synthetic is perfect.

nizmo_freek Experienced

nizmo_freek

Posted
Posted

What are you guys thoughts on the fuchs (spelling??) fully synthetic 15w40 for a rb25det? ive used it in my old gtst rb20det and my current gts25t and never had any problems with it.

RellikZephyr Proficient

RellikZephyr

Posted
Posted
What are you guys thoughts on the fuchs (spelling??) fully synthetic 15w40 for a rb25det? ive used it in my old gtst rb20det and my current gts25t and never had any problems with it.

i use the Fuchs 10W-30 (full syn)

love it good stuff

i think for skylines you need a good full syn oil

RellikZephyr

EVIL TWIN Apprentice

EVIL TWIN

Posted
Posted (edited)

Keep in mind guys, when the RB family of engines were designed in the 80's, synthetic oil wasn't terribly common. They were designed to use a 7.5W-30 mineral oil. Use this as a minimum and anything better will just be a bonus. I've tried the Nissan 7.5W-30 and it's pretty crap compared to pretty much all non-mineral oils.

With the numbers though, the first number (eg 5W) is the weight or viscosity of the oil - the higher the number, the thicker it is. Thicker oils offer greater protection but don't flow around your engine very well, which is where the second number comes in. The second number (eg 50) represents the amount of protection it offers - ie the protection of a 50W oil.

So the ideal situation is to have a thin oil that will flow easily to cover every component as quickly as possible, but have the highest protection.

You don't want to go too thin though like 0W which may actually drain down while sitting at the traffic lights quicker than your idling engine can get the oil up to the top.

I personally use Mobil 1 or Penzoil 5W-50 in my GTR. Probably not entirely neccesary, but I'm not taking any chances - I want the best for my baby :(

Edited by EVIL TWIN
djr81 Grand Master

djr81

Posted
Posted
Keep in mind guys, when the RB family of engines were designed in the 80's, synthetic oil wasn't terribly common. They were designed to use a 7.5W-30 mineral oil. Use this as a minimum and anything better will just be a bonus. I've tried the Nissan 7.5W-30 and it's pretty crap compared to pretty much all non-mineral oils.

With the numbers though, the first number (eg 5W) is the weight or viscosity of the oil - the higher the number, the thicker it is. Thicker oils offer greater protection but don't flow around your engine very well, which is where the second number comes in. The second number (eg 50) represents the amount of protection it offers - ie the protection of a 50W oil.

So the ideal situation is to have a thin oil that will flow easily to cover every component as quickly as possible, but have the highest protection.

You don't want to go too thin though like 0W which may actually drain down while sitting at the traffic lights quicker than your idling engine can get the oil up to the top.

I personally use Mobil 1 or Penzoil 5W-50 in my GTR. Probably not entirely neccesary, but I'm not taking any chances - I want the best for my baby :(

Um, eh?

The first number (before the W) indicates the oil viscosity when cold.

The second number indicates its viscosity when hot.

So mobil 1 5W50 viscosity is 105 centistokes at 40 degrees C & 17.5 centistokes at 100 degrees C. 0W40 equivalent numbers are 80 & 14. The hot end is more important because you can cook the oil in a GT-R quite easilly with no cooler. This is why a higher viscosity hot temperature property can be a good thing.

These are physical properties of the oil & don't refer to it's protection. For that you need look at different API ratings for the oils. I don't know what "the amount of protection - ie the protection of a 50W oil." means.

Try the Mobil website....

http://www.mobil.com/Australia-English/LCW...c_V_Mineral.asp

HRthirtyone Rising Star

HRthirtyone

Posted
Posted

you cant go wrong sticking to manifacturers specs when its a daily driven street car. For turbo piston engines, fully synthetic is better, because of the lower additives, and higher "cooking" point, which is needed when passing through the turbo.

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