I just want to clarify this with some of the gurus on the site.

My understanding is on the 4G63 it is recommended to NOT use a 30w oil, and use a 50w even in a completely stock car?

Reason I have heard is at high rpm under boost the 30w drops oil pressure and may result in Oil Pump Failure. Where as the 50w maintains oil pressure throughout the rpm band?

Is this a correct assessment?

Thanks for your input, please not looking for people that are using a 50w oil to reply or bring in a "oil brand" opinion. I am just looking into the reason to use a 50w oil even on a stock car. I would like some thoughts on that.

Thanks Everyone.

Jeff

 

doesnt mitsu from factory use 10w-30? so i assume thats the best for the car (turbo varies)

 

I have heard that the 30w is great for MPG's but not necessarily best for the motor overall. I am posting this to see what other members have heard, or had experience with.

Jeff

 

What I don't understand is this. Is this in reference to the HTHS of an oil? 30w oil is in the low 3 range where as 50w oil is in the mid to upper 4's in the HTHS ratings.

The Redline 5/30 I run currently has an HTHS score of 3.8 which puts it in the class of a 40w oil. Redline 5/40 is rated at 4.6 which is where most 50w oils are. So are we talking HTHS score (thickness of the oil at temp) or what?

HTHS is the High Temp/High Shear, the ability of the oil to withstand high temps at what rate it shears. Its given a rating, of which certain weights of oils MUST fall into to be called a 30w, 40w etc.

Redline oil runs high HTHS scores that are on average 1 weight higher than most, even other synthetics.

Engine Guru's, some help on this? Why the 50w? and is it true about the Oil Pump failures.

Jeff

 

I am going to run eneos 0w-50, i heard better protection and the engine revs quicker.

 

I use 50w 15 or 20w 50 in the summer works great for beating on the car. Def is more protection when things are really under load. Dad is an engine builder its the same story for v8's and diesel trucks and so on

 

15w 50 mobil 1 for me

 

10w-30 amsoil switching to 10w-40 tho for summer

 

0W30, 5W30 and 10W30 , and whenever i can get away with it 5W20, todays oils can take much more os a beating than yesterdays, therfore the thinner the faster i can spin my engine.
only use thin oils with high quality synthetics, mobil 1, castrol, ect.. are not high quality.

this topic has been beaten to death.

 

This topic has NOT been beaton to death, this is not an oil comparo of brands. What I am saying is there is proof out there that the use of a 30w oil in the Evo may cause Oil Pump Failures. MANY tuners and engine builders recommend a 50w oil not that it itslef is better than any particular brand of today or yesteryear, its about oil pressure. The higher the viscosity the oil pressure increases which keeps the oil pump happy.

Therefore a 50w would be better to use. That is the point I am trying to make, and trying to get confirmed by other engine guru's here on the board.

I am trying to see if this is due to a need for a high HTHS oil or just the fact that its a 50w period. Since the Oil I use even though its a 30w carries the HTHS score of a 40w, and if I use their 40w it carries the HTHS score of a 50w. So is this a HTHS related issue with the oil pump failures, or simply just a thicker viscosity period.

Any Engine guys that know anything about this, your help would be needed. Is there any proof that engines blow Oil Pumps any quicker/sooner on 30w vs 50w or is this just people abusing the engine?

Thanks for your time.

Jeff

 

if you want to get super technical its depends on your bearing clearance on your engine. stock motor has tighter tolerances than a built motor that could have bearings setup for 50w. the thicker oil will cushion the bearings better under load preventing any scoring of the bearings aka spun bearing. the most common cause of engine failure.

 

if you guys wouldn't mind go to this link:

https://www.evolutionm.net/forums/sh...=427325&page=3

look at john bradleys replies about 50w oil. He is not the only one that says what he is saying. I have been hearing it allot..

just not sure what to think of it.

Jeff

 

id go with 50 wight form mobil 1 and they also garantee that it will last 15 thousand miles

 

mobil-1 meganac 10-40w is what i use ....

 

have switched up my oil numerous times since my engine was rebuilt 20k ago, ive ran royal purple 15w40, mobil 1 10w30(never again) haha, castrol synthetic 10w30, and this time i changed my oil im runing the valvoline vr1 synthetic 20w50, i do hear some lifter tick or maybe its my valvetrain is a little noisy(built), till oil gets up to temp couple wot pulls once warm, it pretty much goes away.. i have to say i do like the valvoline, and its under fps recommended oils for there fp red.....oh btw 20k miles 64mm fp red 26 psi stock oil lines haha