RTS 5W/40, 4644 miles, 08 WRX STI

gathermewool

Site Donor
Joined
Jan 9, 2009
Messages
9,197
Location
New England
First sample in April was Cam2 5W/30, 3022 OCI Current sample is Rotella Synthetic 5W/40 (CJ-4). A lot of highway, some WOT runs
 
Last edited:
Joined
Aug 4, 2003
Messages
2,515
Location
NJ
Hmm, a low 40 grade after 4,600 miles (not that I know what that means). Refresh my memory, has Terry said much about your silver and copper? Do you have mods? Nice TBN. Silicon is creeping up. -Dennis
 

gathermewool

Site Donor
Thread starter
Joined
Jan 9, 2009
Messages
9,197
Location
New England
I can only guess that it sheared down - might have been due to fuel dilution - but, like you, I'm not sure what it means. Seems thick enough for me at the end of the OCI. Terry isn't overly concerned with the Cu, but wants to keep an eye on the Ag. At 2 ppm and steady over two varying chemistries and OCI I'm not too worried about it myself. He suggested, as he did last time, that I switch to RLI. I'm still on the fence about spending twice the money with out doubling or close to doubling my OCI. As far as Si is concerned, Terry wants me to replace my air filter. I'll pull the filter some time this week to see how it looks for myself. I really can't believe that I've exceeded the capacity of the stock paper filter in 13kmi, but I could be wrong. I'm not concerned with the minimal reduction in air flow. It's my understanding that the ECU will build boost to target, and even a moderately dirty filter won't cut down too much on air flow. I'm still pretty new to FI cars, but I'm sure some one here will enlighten me. It all boils down to me trying to buck the system and do things as efficiently as possible. I plan to run this sump of RTS out to 7kmi. I might send off another sample, and change out with RLI for a few runs more to feed my dorky need for information rather than for any actual benefit. haha
 
Last edited:
Joined
Jul 23, 2009
Messages
224
Location
Durham, NC
 Originally Posted By: chevrofreak
RTS is known to shear quite significantly.
How much is significantly? A thin 30wt? A thick 30wt? A thinner 40wt? I was thinking about running Rotella T syn in my WRX next OC....I hear nothing but good things about this oil for Subbies, that's why I ask.
 
Joined
Oct 30, 2002
Messages
41,140
Location
Great Lakes
Looks like quite a bit of moisture in addition to fuel, too. Are you doing mostly short trips? Have you given the engine a good run prior to drawing a sample? What's Cam2?
 
Joined
Jun 17, 2005
Messages
4,942
Location
Billings, MT
 Originally Posted By: 09rexwagon
 Originally Posted By: chevrofreak
RTS is known to shear quite significantly.
How much is significantly? A thin 30wt? A thick 30wt? A thinner 40wt? I was thinking about running Rotella T syn in my WRX next OC....I hear nothing but good things about this oil for Subbies, that's why I ask.
It can shear to a thick 30, but typically just goes toward the very low end of 40. The reality is, viscosity isn't the most important thing about oil. It still protects fine, even when it's thinned out.
 
Joined
Sep 28, 2002
Messages
39,802
Location
Pottstown, PA
Correction, if it was an M1 0w-40 UOA no mention of shearing would have been made at all. It's a feature with that oil. You can celebrate it.
 
Joined
May 1, 2003
Messages
9,448
Location
USA
As long as the shearing is not the cause of the wear and I do not think it is in this case I do not see where the shearing matter's much! Most anything you put in that engine is going to be sheared! That is just a fact. RLI is too rich for my blood for that type of money they need to send a guy out to my house to change my oil and another guy or gal to give me a massage while I wait for them to do the oil change! I would never in a million years put a 0W40 in a turbo charged Subie. I think the RTS 5W40 is doing a good job with regards to wear metals. Since the silver was their with two different oils with two different chemistry's I do not see where this is an oil or oil additive issue at all. If you wanted to to get the chemistry up a tad I would stick with RTS and add 1 quart of Redline 5W40 to each oil change and see what happens over the course of the next 2-3 oil changes. The extra molly and ester content and PAO content should bring the numbers down with in 2-3 oil changes doing this! I have done this in a hard working Corvair engine used in an aircraft and it has worked out well. Since this is a similar engine design I do not see why it would not work out well for you and be a lot cheaper. It can not hurt to try it! Carquest can order any Redline product you want and they normaly have it in about 3 days or less. Their price is not that high for Redline products especialy if you just want to try one quart added to your oil to sweeten it a tad. It would be far cheaper then going the RLI route and if it works it will be a good thing. It cannot hurt anything to try it. For the record Terry at one point had a business that was based on telling you which over the counter oils to blend at home for your specific application. So I am not recommending anything that Terry himself at one point did not also market!I have tried what I recommend and have had decent results with it. I have also gone the other direction and added RTS 5W40 to VP Racing oil to bring up it's viscosity a tad and improve it's life cycle in a daily driver....In fact this summer I have one more blend of RTS5W40 and VP Racing oil 5W30 so I will run it and show off my results this coming summer! Another way to go would be to add 8 onces of Lube Control to your oil when you change it and then add 1 once every 1000 miles. It would take two OCI's to see the results but I think added to the RTS 5W30 that it might also be enough to bring the wear numbers down and it would be much cheaper then going the RLI route!
 
Last edited:
Top