Enligthen me on MOTUL XCESS 5w40 4 stock EJ257(hear me out first)

SDblitz858

New member
Heyfam, please remove if it does not belong here and yes I have done my researchbut I am still confused to weather go by what the manual says or go by what isthe best for this engine. Again, I have a completely stock 2018 Subaru Sti,21000 Miles right now and all I have put is Subaru OEM 5w30 oil and lastchanged 19kmiles with AMSOIL signature series 5W30. For warranty purposes(found our later on its not even API certified for warranty use only XL series)I am in San Diego CA and thru word of mouth around me and research that If I wantthe longevity of my engine and keep bearings happy I have to use a 5W40 oil. PreferablyMotul Xcess 5w40 on a stock engine.Can someone please enlighten me if I can useMotul Xcess 5w40 on a stock engine to prolong its life? Or do I have to bemodded at the very least to use that oil? Also heard its not suggested if youhave a stock cat. Now im lost again since most are suggesting it for a stockSti but not with stock cat? Any response is gladly appreciated. Also, I Daily the car and occasional mountain runs.
 

Alin

Diehard Car Enthusiast!
@SDblitz858

Ah, the topic of oil... Here's a response I wrote about a month and a half ago to someone else: https://www.igotasti.com/vBforum/th...ru-Impreza-STI?p=145481&viewfull=1#post145481

Oil has become a topic I try to steer away from because everyone has a different opinion regarding it. There is no right or wrong answer as long as the oil is fully synthetic, is of the right weight, and meets/exceeds it's intended purpose for a specific application. When it comes to temperature and viscosity, it'll really come down to what application you'll be using the oil for. If you're racing and temperatures reach really high, then you're better off with oil that is intended for higher temperatures and created for racing purposes. If you only drive around on public roads and do some spirited driving here and there, you're better off with oil such as Rotella T6.

Money is out of the equation because what you value may not be the same as what I value. You have to determine for yourself what you're willing to spend on oil and if it's worth it to you personally.

The best answer that I can give you is this: YOU
have to try out each individual oil brand and type for YOURSELF and get Used Oil Analyses (UOA's) done on each individual one. I've used Blackstone Labs a multitude of times and I high recommend them to do it. :tup:

If you care, I've been using Rotella T6 as my only oil of choice in ALL of my vehicles for a number of years now. I decided at one point that for my application, this is the best oil for me to use. The biggest advantage of this decision is that it's really cheap and easily/readily available at Walmart. I use it in both gasoline and diesel engines.



Based on your statement: "I daily the car and do occasional mountain runs," I would suggest you just stick with Rotella T6, even though it's not OEM spec (5W-40). It's so cheap in comparison to the other oils that anyone can afford oil changes every 3,000 miles. The key is to check your oil level and change it on time. I also stop driving hard when the oil life has reached around 2,500 miles. There are a plethora of UOA results on Rotella T6 and reassurance from many other Subie owners. It's proven again and again why it's a great bang for the buck oil. However, it ultimately comes down to YOUR decision.
 

Eagleye

Tinkerer
I pretty much agree with everything [MENTION=1172]Alin[/MENTION] is saying above. If it is stock up to stage 2 I see no reason to run anything different than T6. You can if you want but I doubt you are gaining anything from it other than space in your wallet. Once you get a built block I would listen to your builder and tuner. Watching the oil level and changing at appropriate intervals will be the biggest key to longevity.
 
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