Castrol Edge Euro 0W-40 A3/B4 - 3,305 Miles - 2010 Subaru Impreza WRX EJ255

Wow, the Titanium 41 and Zinc 975 really stands out. Looks like they went all-in on the Titanium and quite high ZDDP for their anti-wear additives.

I did read somewhere that >800 zinc may be problematic for the catalytic converters but I don't know if there's any truth to that.

I've got 10qts of this, looking forward to using it on an upcoming service. Thanks for sharing!
It's actually phosphorus that causes cat problems if you are burning a lot of oil. Edge 0W-40 doesn't actually have a lot of phosphorus compared to other oils that meet similar ACEA and builder specs.
 
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granted the N/A engines don't see the oil temps you turbo guys do, but this was my driver's side valvetrain at 135k miles when i had to replace a valve cover gasket. synthetic from day 1 with mostly 6-8k mile oil changes. autocross, rallycross, track days, mountain roads...plenty of severe service. i tried everything from 0W-30 up to 5W-40 and settled on 0W-40 by the end before it was hit and totaled.

i think you can achieve the same results, just keep the OCI's shorter due to the engine's higher specific output. i would also stress to be sure you are careful in your oil filter choice, some filters may not have the proper bypass PSI which for EJ's is higher than most. i always just used OEM filters from the dealer.


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Funny you mention oil filters. The blue filters Subaru switched to (not sure when, but around 04 IIRC) don’t have the correct bypass valve pressure rating! When I got this car I researched like mad and found out the black Tokyo Roki filters (ones Subaru used before switching, still used in Japan) had the correct rating. Given I was driving the car back home and was pressed for time, ordering the black filters online was out. Thanks to whoever that genius that figured out the 09-11 Mazda RX-8 used the same exact filter, albeit a bit larger, which is a plus anyway. A local dealer had them in stock so got the oil changed with Castrol and have been using that combo ever since. Always get a kick out of telling the Mazda guys the filter is going on a Subaru :LOL:

Thanks for that tip though, and for sharing that picture. That’s CLEAN! I may revisit M1 again and give it a go. My main concern is viscosity which seems on the thinner end of 40. Trying to protect those EJ bearings best I can.

Wow, the Titanium 41 and Zinc 975 really stands out. Looks like they went all-in on the Titanium and quite high ZDDP for their anti-wear additives.

I did read somewhere that >800 zinc may be problematic for the catalytic converters but I don't know if there's any truth to that.

I've got 10qts of this, looking forward to using it on an upcoming service. Thanks for sharing!
It's actually phosphorus that causes cat problems if you are burning a lot of oil. Edge 0W-40 doesn't actually have a lot of phosphorus compared to other oils that meet similar ACEA and builder specs.
To be honest I still need to look into what all this means to be better understand it all. Thanks for pointing me in the right direction and confirming once again Edge is awesome :)
 
Funny you mention oil filters. The blue filters Subaru switched to (not sure when, but around 04 IIRC) don’t have the correct bypass valve pressure rating! When I got this car I researched like mad and found out the black Tokyo Roki filters (ones Subaru used before switching, still used in Japan) had the correct rating. Given I was driving the car back home and was pressed for time, ordering the black filters online was out. Thanks to whoever that genius that figured out the 09-11 Mazda RX-8 used the same exact filter, albeit a bit larger, which is a plus anyway. A local dealer had them in stock so got the oil changed with Castrol and have been using that combo ever since. Always get a kick out of telling the Mazda guys the filter is going on a Subaru :LOL:

LOL go figure, that's Subaru for you. when I got the car I recall purchasing a huge stash of the "original" blue filters that I had heard were the business and ran them the entire 10 years i had it, and even had to sell some leftovers when the car was totaled. I wonder if those were the correct ones? I never had an issue and hadn't heard about the RX8 trick!

for your turbo, i'd stick with Castrol for the reasons you stated exactly - those thin rod bearings and turbo heat. the M1 is great for my fleet which is more suited to a thick 30 weight, which in reality is what the M1 0W-40 is.
 
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LOL go figure, that's Subaru for you. when I got the car I recall purchasing a huge stash of the "original" blue filters that I had heard were the business and ran them the entire 10 years i had it, and even had to sell some leftovers when the car was totaled. I wonder if those were the correct ones? I never had an issue and hadn't heard about the RX8 trick!

for your turbo, i'd stick with Castrol for the reasons you stated exactly - those thin rod bearings and turbo heat. the M1 is great for my fleet which is more suited to a thick 30 weight, which in reality is what the M1 0W-40 is.
Haha right exactly. Aside from not having the correct bypass valve pressure I also read they were made by FRAM :eek: From my reading, no version of the blue filter was ever the 'correct' one. Only the black Tokyo Roki Made in Japan ones. But it's Subaru. It's possible there was a 'good' blue version that went through internal changes. Pure speculation though.

Okay thanks so much for that. I was thinking maybe I was being unfair to M1. There's always that temptation to tinker and change things up but in this case, I think it's literally "if it ain't broke don't fix it" ;)
 
Okay thanks so much for that. I was thinking maybe I was being unfair to M1. There's always that temptation to tinker and change things up but in this case, I think it's literally "if it ain't broke don't fix it" ;)

we've all been there! i'd run 3-4 rounds of castrol through it with analysis and see how it does, then alter your tactics if you're seeing a bad trend. otherwise just get a good safe tune on that EJ and let it rip.
 
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