recomended engine oil

#1
any kind soul can advise on wht kind of engine oil to use for evo 9.
brand?
40w/50w??
gd and bad?

very new to the car.
current mileage ard 4000km.

thanks in advance
 

DoggieHowser

Moderator
Staff member
#2
Most of us use 50 grade engine oil because of the warmer climate here.

FWIW, in the endurance tests in Best Motoring, the Evo and STI were using -60 oil. Since most of us don't run endurance, I think -40 and -50 tends to be OK. If you do drive hard, change frequently, abt 5000kms or so.

I am using Apexi GT -50 oil.

Will probably try the Endless one next.
 
#5
DoggieHowser said:
Most of us use 50 grade engine oil because of the warmer climate here.
In the Evo engine, I wonder if heat is the real concern or fuel dilution, hence us running a higher viscosity oil. The operating temperature of our cars on hot Singapore roads never exceed 100 degrees. Even a 0W30 oil can cope with that.

I'm worried that running a heavy weight oil will be detrimental to the engine because of poor flow to the critical areas. After all, the factory spec is to run a 30 oil.
 

Privateer

Well-Known Member
#7
Tanzy said:
In the Evo engine, I wonder if heat is the real concern or fuel dilution, hence us running a higher viscosity oil. The operating temperature of our cars on hot Singapore roads never exceed 100 degrees. Even a 0W30 oil can cope with that.

I'm worried that running a heavy weight oil will be detrimental to the engine because of poor flow to the critical areas. After all, the factory spec is to run a 30 oil.
What do you mean by "fuel dilution"?
 
#8
Privateer said:
What do you mean by "fuel dilution"?
Fuel dilution definition
"Fuel dilution of the engine oil is the direct result of partially burned or liquid fuel entering the crankcase from piston ring blowby or fuel system leakage."
http://www.knowyouroil.com/amsoil/articles93.htm

Engine which tend to run rich, typical of turbo cars, tend to suffer more fuel dilutions than NA cars. Also cars that make many short journeys also are at increased risk due to the car running rich during startup.
 

Privateer

Well-Known Member
#9
Tanzy said:
Fuel dilution definition
"Fuel dilution of the engine oil is the direct result of partially burned or liquid fuel entering the crankcase from piston ring blowby or fuel system leakage."
http://www.knowyouroil.com/amsoil/articles93.htm

Engine which tend to run rich, typical of turbo cars, tend to suffer more fuel dilutions than NA cars. Also cars that make many short journeys also are at increased risk due to the car running rich during startup.
Let me rephrase. "What does role does oil viscosity play in fixing fuel dilution problems?" Even in the page you linked, there is no mention of increasing oil viscosity to treat what is essential a mechanical problem (lack of piston ring sealing). Essentially if you use 30W or 50W oil, the viscosity will be reduced, no matter what.
 
#10
This is going along the line that if fuel dilution occurs, a 30WT oil will be reduced to a viscosity too low to be of any protective value before the next oil change. Therefore, using a 50WT oil initially will help reduce the effects of fuel dilution.
 

Privateer

Well-Known Member
#11
My opinion is that when fuel dilution becomes an issue, oil viscosity or even oil change intervals are the least of one's worries. Treat the disease, not the symptoms. :)
 
#12
Privateer said:
My opinion is that when fuel dilution becomes an issue, oil viscosity or even oil change intervals are the least of one's worries. Treat the disease, not the symptoms. :)
Then back to my initial query. Assuming no fuel dilution, then why are we using such thick oils when we are seeing oil temperatures in our engine during daily that allow the use of lower viscosity oils then 50WT. I'm worried that the poor flow characteristic of heavy weight oils could be damaging our engines instead of the conventional, uneducated believe that thicker oils protect engines.
 

Privateer

Well-Known Member
#13
Tanzy said:
Then back to my initial query. Assuming no fuel dilution, then why are we using such thick oils when we are seeing oil temperatures in our engine during daily that allow the use of lower viscosity oils then 50WT. I'm worried that the poor flow characteristic of heavy weight oils could be damaging our engines instead of the conventional, uneducated believe that thicker oils protect engines.
It has been answered by the viscosity link that was provided earlier. Also, I don't quite understand what you mean by "poor flow characteristic of heavy weight oils"? If you've ever seen 50 weight oils as compared to 30 weight oils, you won't be able to tell the difference visually. It just means that at 100 degC, the heavier oil will remain more viscous as compared to the lighter oil.

A lot of standards bodies and companies have conducted lots of tests on engine oils, and viscosity is NOT the sole indicator of performance (of which there are many criteria e.g. resistance to shear, foam, vaporization etc). Generally speaking though heavier oils tend to retain their properties better despite being subject to higher operating temperatures, and that's why heavier weight oils are preferred. There is some loss of power from the higher viscosity due to windage losses but I'm not sure whether that is a major inefficiency since the stock Evo engine is using conventional wet sump lubrication anyway.
 
#14
Since "viscosity is NOT the sole indicator of performance", and I totally agree, then why are the workshops pushing for 50WT oil to be used in the Evos? A Sunny, Type R or Altis also reaches oil temps of 100degC with normal driving, why do they stick to manufacturer oil viscosities whereas Evos use 50 when the recommended by Mistubishi is 30? That's is what I am trying to find out.
 

Privateer

Well-Known Member
#15
Tanzy said:
Since "viscosity is NOT the sole indicator of performance", and I totally agree, then why are the workshops pushing for 50WT oil to be used in the Evos? A Sunny, Type R or Altis also reaches oil temps of 100degC with normal driving, why do they stick to manufacturer oil viscosities whereas Evos use 50 when the recommended by Mistubishi is 30? That's is what I am trying to find out.
The primary reason is that the instruction manuals are for a worldwide audience, which experience cold weather and so cold-starting and pumping is an issue. Additionally, the specific output of a Sunny/Altis/Type R is not even comparable to the Evo which is turbocharged. Finally, the trend is towards fuel economy, and so lighter weight oils are typically specced to appease the greenies.
 
#16
Fuel economy appeases my wallet too you know. Not just greenies.

I'm just worried that with our short journeys and frequent start ups, the slower flow of high weight oils could be harmful to the cold engine. Specific output doesn't matter on start up where most of the wear occurs.
 

Privateer

Well-Known Member
#17
No disagreement on major engine wear being cold start operation. However, the ambient temperature is on average high 20s to low 30s degC, and we will never see -10 degC weather.

Best practice probably is to use 10W30 for daily drive and a heavier oil for track use or frequent high revs since the heavier oils tend to show better wear resistance (ASTM D-4172B).
 

Privateer

Well-Known Member
#18
According to my old Evo 7 workshop manual, there is no recommended oil. Any oil that meets API SG (which has been superseded) or ACEA A1, A2 or A3 can be used. There's also a note on page 153 that says:

SAE 5W-30 can be only used at the area where the lowest temperature is lower than the applicable temperature of SAE 5W-30
Beside it is a diagram that shows the ambient temperature of SAE 5W-30 to be between -40 and 40 degC.

Dunno if it applies to the later Evo models.
 

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