Previous oil was Redline 5w30 with a Bosch filter. This was with a the black Tokyo Roki OEM filter.
Previous report:
http://darksti.com/UOA/AWDJT-D64272.jpg
RP 10w40 2006 STI 3,624mi
- Thread starter DARKSTI
- Start date
Previous oil was Redline 5w30 with a Bosch filter. This was with a the black Tokyo Roki OEM filter.
Previous report:
http://darksti.com/UOA/AWDJT-D64272.jpg Originally Posted By: ZZman
Looks pretty good but for a premium oil it was a waste to only run it 3600 miles. It did have a borderline low viscosity for such a short run but I believe RP tends to shear.
Last edited:
Originally Posted By: d00df00d
Looks like you've got big fuel dilution. Lots of short trips?
Originally Posted By: DARKSTI
A mix, about 40mi every day or so and sometimes 20mi, this also included a trip to San Francisco which was about 500mi total. I also drive in the mountains often and I have a bit of a lead foot on on-ramps and in the mountains :)
Originally Posted By: DARKSTI
Also, what part of the UOA shows the fuel dilution? As I am learning
Yeap, I do go WOT quite a bit, but mostly around 75%-90% lately to try and up my gas a mileage a bit.
Thanks for explaining the ECU bit and the fuel dilution also :)
I will try and not go as hard to see what happens this go around.
Right on.
Doesn't sound too bad, but remember, highway trips (preferably spirited) are your friend.
Do you go WOT when you drive hard? Try not to go past 80-90% on this next OCI and see what happens. Most ECUs usually run a little rich at WOT, so that might cut down on your fuel dilution without actually slowing you down.
Well I can't be sure because I'm only an amateur myself and the report doesn't give all the necessary data. However, I'm guessing there's fuel dilution because:
- Both the flash point and the viscosity are much lower than the virgin oil
- This happened with every oil you had, including Red Line 5w-30, which never thins out unless it's diluted (as far as I know)
- Subaru engines are usually very easy on oil, so they're not likely to cause shearing except maybe with track use
Originally Posted By: d00df00d
Originally Posted By: DARKSTI
A mix, about 40mi every day or so and sometimes 20mi, this also included a trip to San Francisco which was about 500mi total. I also drive in the mountains often and I have a bit of a lead foot on on-ramps and in the mountains :)
Originally Posted By: DARKSTI
Also, what part of the UOA shows the fuel dilution? As I am learning
You can still go hard, just don't go WOT. If you feel the pedal hit the floor, back off a tiny bit.
BTW, don't take what I say as gospel. I'm reasonably confident saying it, but really I'm just guessing based on general info. I would run it by some real experts to be sure.
Originally Posted By: d00df00d
You can still go hard, just don't go WOT. If you feel the pedal hit the floor, back off a tiny bit.
BTW, don't take what I say as gospel. I'm reasonably confident saying it, but really I'm just guessing based on general info. I would run it by some real experts to be sure.
- Messages
- 15,375
- Location
- N.H, U.S.A.
2HP/Cu-in can do a job on an oil, If this was a Chevy small block V8, it be making 700HP so, I dont think I'd put PP in this beast - Super premium stuff only. Does that leave out RP too?
Originally Posted By: addyguy
Good call on the OCI if you're under warranty. If you're not, run the oil longer, OR switch to something cheaper - RTS 5W-40 does well here.
In your previous run, I'm really, really suprised to see Redline shear down so much in 2500 or so miles.
Originally Posted By: ARCOgraphite
2HP/Cu-in can do a job on an oil, If this was a Chevy small block V8, it be making 700HP so, I dont think I'd put PP in this beast - Super premium stuff only. Does that leave out RP too?;)
Last edited:
Originally Posted By: JoeFromPA
DarkSTI -
If you want super-duty oil suitable for your temps, try M1 15w50 :)
I'm gonna run it in my 08 LGT next OCI, see how it feels and what a UOA says...especially since it won't be going under 60 degrees for the next few months.
Originally Posted By: addyguy
I agree with Joe, M1 15W-50 is also a great alternative for hot weather driving.
Fair enough. Royal Purple 10w40's flashpoint, per RP's website, is 400 F. It's starting viscosity is 14 cst 100 c, and 75 SUS 210F.
In an engine like the STI (known for fuel dilution and hot turbos), I'd want an oil with a little more robustness personally...you can see in your analysis that it sheared (within grade), though the flashpoint either wasn't calculated accurately or it didn't move much. I don't know RP's HTHS though.
Just my .02
Originally Posted By: JoeFromPA
Fair enough. Royal Purple 10w40's flashpoint, per RP's website, is 400 F. It's starting viscosity is 14 cst 100 c, and 75 SUS 210F.
In an engine like the STI (known for fuel dilution and hot turbos), I'd want an oil with a little more robustness personally...you can see in your analysis that it sheared (within grade), though the flashpoint either wasn't calculated accurately or it didn't move much. I don't know RP's HTHS though.
Just my .02
Similar threads
