05 Wrx. Which Amsoil?

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Apr 6, 2011
Hello bitog. I have a 2005 Subaru Impreza Wrx. Intake, turbo inlet, intercooler y pipe, Up pipe, Down pipe, Catback, Cobb stage 2 tune. I like to drive my car hard from time to time, and I also love my car to death. Therefore I would like a good oil. I have heard 5w30's can be bad for these engines due to shear thanks to the turbo (+mods +driving hard). But, I have heard the "better" 5w30's are more stable and shear resistant. If I went with Amsoil, should I use 5w30 as Subaru recommends, or a 5w40 as most Subaru tuners recommend? If I were to use an Amsoil Euro car formula 5W40, would I be best of with low SAPS, mid SAPS or full SAPS? First oil change after buying this car I used Mobil1 syn 5w30 and oem filter. Then I read all the horror stories with 5w30 on these cars and switched to Mobil1 0w40 euro and oem filter for the past few changes. Seems like both my engine and self like the M1 0w40 over their 5w30. Go through about 1 qt every 3k mile oil change. That is why I am curious about the Amsoil Euro 5W40, or if I should just use Amsoil 5w30. Lastly, would it be bad in any way to mix the Mobil1 0w40 Euro and the Amsoil 5w40 Euro? Say I use the Mobil1 0w40 for the oil change, and use the Amosil 5w40 as a periodic top off (go through about 1 qt every 3k mile oil change). Would that be alright since they are both pretty good euro w40? Or is mixing oils like that bad if you really care?
5w-40 or 0w-40 synthetic. M1, M1 TDT, Edge, Synpower, Rotella, Delo, PP, Amsoil, Redline take your pick. They are all good oils. I'd go for what's cost effective. I'm stage 3 in the leggy and M1 0w-40 gets it done. I'd only go to T6 if your tracking. Amsoil/redline/motul are not cost effective for me. 4-5k OCI. Subaru Roki filter. Top off is always best with same brand/grade. But if you have to add something, it's not going to ruin your engine to mix a bit of other oil in.
The above info is spot on. If you want to use AMSOIL, the full-SAPS Euro 5w-40 is the way to go. Their HDD 5w-30 would be okay too. The Rotella T6 5w-40 that's popular with the Subaru crowd here will work just fine, and there's a current rebate from Shell. Stock up.
So are there any downsides to "mixing" two different good synthetics? (topping off M1 euro 0w40 with Amsoil euro 5w40) Why would their full saps 5w40 be better for this particular engine than their mid saps 5w40? Ive read quite a few people saying that the Mobil1 Euro 0w40 is actually better than the Amsoil Euro 5w40. Is that just based on price? Or is the M1 euro actually better than the Amsoil euro?
Originally Posted By: 94exa2
So are there any downsides to "mixing" two different good synthetics? (topping off M1 euro 0w40 with Amsoil euro 5w40) Why would their full saps 5w40 be better for this particular engine than their mid saps 5w40? Ive read quite a few people saying that the Mobil1 Euro 0w40 is actually better than the Amsoil Euro 5w40. Is that just based on price? Or is the M1 euro actually better than the Amsoil euro?
As far as mixing goes there are many used oil analysis here on bitog with frankenbrews and I've yet to see ANY ill effects,and I have only bought 20 and 40 grades for a few years now and I mix different brands and grades to achieve different viscosities based on ambient temps and how the vehicles are operated and my engines are spotless and run beautifully. So mix away. As far as m1 being better than Amsoil that is a question for the ages. First off specify better. As far as quality is concerned I believe that each line would have to be compared as an apples to apples comparison. For example the SSO line would have to be compared to the EP line,and honestly I feel Amsoil is a better product however in day to day driving I doubt a person could distinguish one oil from the other in identical engines with identical operating conditions. I used Amsoil exclusively up until a few years ago and the only reason I'm not using it anymore is cost. If the cost isn't a factor to you then I'd use the SSO line and establish a proper interval by getting a few used oil analysis done so you can maximize your return on the initial cost. For me I buy oil on rollback when jugs are cheap. Here Amsoil SSO is 15 a quart,so I just cannot justify that cost anymore,especially when I change the oil at 10000 miles unless I feel it should be changed sooner. I ran Amsoil 5w-30 SSO in my 99 silverado for 100k and when we swapped the cam the heads and oil galleys and the engines innards were absolutely spotless. The cam had a wear groove you could feel with your fingernail but was so slight I want to say it was almost non existent,and by then the engine had 150k on it. The lifters themselves had no wear that could be seen or felt,well nothing I can really say was a problem anyways. So in my experience Amsoil is a top notch product,just pricy when compared to the cheaper Walmart sourced products and for me I just can't justify paying extra,unless of course taking the oil out to the 25000 mile interval that Amsoil claims is possible. I just can't do it on a gasser. But that's a personal thing with me. 10000 miles is as far as I'm prepared to go and the 25 dollar Walmart jugs of syn get me there. M1 0w-40 is great stuff as are all the euro spec oils. If your going to use Amsoil buy it through Pablo here on the forum. I haven't ever read a negative review of his service to the forum and from what I understand he can provide pricing that can't be beat. So support him if you are going the Amsoil route.
Sometimes its hard to find the M1 0w40 Euro in single qt bottles (for topping off), and I have a buddy that is an Amsoil dealer so I can always get it from him, at his price. Although it is slightly more than the M1, it is easier for me to get. I usually dont have a problem finding the Mobil1 0w40 Euro in 5 qt jugs, which I use for the oil change. But I still end up having to buy another quart for top offs, and it is easier for me to get the Amsoil 5w40 Euro in 1 qt bottles, though very slightly more expensive.
Originally Posted By: bluesubie
I think I just replied to you on nasioc. smile -Dennis
Quite possibly lol. Figured I would try to hear what the turbo boxer Subie guys have say, and hear what the oil guys had to say. Also, would it be safe to add Mobil 1 Turbo diesel truck 5w40 to the M1 Euro 0w40 during top offs? Both Amsoil Euro 5w40 and Mobil 1 Tdt 5w40 seem to be much easier to find in 1 qt bottles than my Mobil 1 Euro 0w40. Just be careful making sure its safe and wont some how make my M1 0w40 "worse" lol.
Why would the Full Saps Euro 5w40 be better than the mid Saps Euro 5w40? Would Mobil 1 Turbo diesel truck 5w40 be better to use for top offs than the Amsoil?
If Amsoil is your brand, all their 0w40, 5w40, and 10w40 oils would all work great. Concerning SAPs, check the tbn of these oils. I prefer higher tbn for my negligent oil change intervals. I also prefer PCMO over HDEO because or my E10 addiction and white sludge. Top off oil for consumption is ANY 40 grade synthetic if Amsoil wasn't available. I'd even consider a 5w50 or 10w60 for excessive consumption.
From the Amsoil website: [quote]"Subaru has published Service Bulletin # 02-103-07 that identifies a factory design related problem with premature clogging of the oil mesh screen located inside the oiling system that supplies the turbo charger on all model turbo charged cars. A clogged screen will result in oil starvation and turbo charger failure. Subaru has since published Service Bulletin #02-110-10R indicating that 2010 MY and prior turbocharged engines continue to require oil and filter change intervals of 3,750 miles (6,000 km) or 3 3/4 months, while all 2011 MY turbocharged engines have returned to the original requirement of 7,500 miles (12,000 km) or 7 1/2 months, and they are required to use synthetic oil. Due to the issues outlined in this document, AMSOIL recommends following Subaru drain interval recommendations."[end quote] So this engine is not a good candidate for extended OCI. Seems to be a waste of money and oil to use the Amsoil SS series. I would consider Amsoil XL 5w-30 with a HTHS of 3.3. Another would be Kendall Euro 5w-30/40 with a HTHS of 3.5/3.7... The Kendall is a API/SN, ACEA C3-10, A3/B4-08. Meets a bunch of Euro OEM specs. My choice would be the Kendall due to the C3 (CATALYST friendly)JMO Kendall is a bit hard to find, but can be bought online at a reasonable price here. http://www.petroleumservicecompany.com/kendall-gt-1-fs-5w-30.html Other folks have had good service from this company.
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