Tried 5W30 in our Sube 2.5 for some 6-7 years as an experiment and the engine is now noisy with high oil consumption, the end of 30W ols in any vehicle we own/will own. The dealer uses 10W40, I'll be using 5W40 in it from now on as I should have done from purchase. You live and learn
40wt in Subaru 2.5?
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Originally Posted By: Thermo1223
After 5k on T6 I am doing a used oil analysis so I'll post it up.
It will be mostly summer with some WOT and a bit of hard driving here & there. No track use and the engine is performing above rated HP at least for a Forester. Since technically it is a detuned STI block it is actually in spec with that.
I tried 3 oils prior to this but never got a used oil analysis. A local Subie guy put in Amsoil, which turned very thin, very quick and just felt harsh and blah. I am pretty sure it was XLF.
I then had GC in for a short stint before my turbo seals went. After that is was local shops oil at 3k OCI's because it was winter & I was doing ARX at the time. They used Carquest filters so I'm sure it is a bulk Carquest oil. It came out real thin but the car felt much better than the Amsoil. I don't remember the GC so much.
The T6 I have it now feels great, very smooth. I used to have quite the shake at idle sometimes an uneven idle but with T6 no more. I know boxer engines do this but mine was really pronounced at times. I wonder if it had something to do with thinner oil and the cam phasing system.
I am running Pennzoil Platinum 5w30 in it now and I have quite a bit of shake at idle. This is one of the reasons I was thinking of going to the 40wt.
After 5k on T6 I am doing a used oil analysis so I'll post it up.
It will be mostly summer with some WOT and a bit of hard driving here & there. No track use and the engine is performing above rated HP at least for a Forester. Since technically it is a detuned STI block it is actually in spec with that.
I tried 3 oils prior to this but never got a used oil analysis. A local Subie guy put in Amsoil, which turned very thin, very quick and just felt harsh and blah. I am pretty sure it was XLF.
I then had GC in for a short stint before my turbo seals went. After that is was local shops oil at 3k OCI's because it was winter & I was doing ARX at the time. They used Carquest filters so I'm sure it is a bulk Carquest oil. It came out real thin but the car felt much better than the Amsoil. I don't remember the GC so much.
The T6 I have it now feels great, very smooth. I used to have quite the shake at idle sometimes an uneven idle but with T6 no more. I know boxer engines do this but mine was really pronounced at times. I wonder if it had something to do with thinner oil and the cam phasing system.
I am running Pennzoil Platinum 5w30 in it now and I have quite a bit of shake at idle. This is one of the reasons I was thinking of going to the 40wt.
I use Pennzoil Platinum 5w-40 European and I have no issues. I drive 95% highway and do at least 100 miles a day. I need to find a good 5w-40 can buy off the shelves... Pennzoil but it is hard to find.
Originally Posted By: thunderchild
I use Pennzoil Platinum 5w-40 European and I have no issues. I drive 95% highway and do at least 100 miles a day. I need to find a good 5w-40 can buy off the shelves... Pennzoil but it is hard to find.
T6, Mobil 1 Turbo Diesel Truck, and M1's 0w40 are good choices for the boxer engine if you want to use a OTC syn. So is a 10/15w40 conventional in the summer. I have a thing for conventional oil in the subaru and run 40 weights in the summer. I'm thinking of sticking with a good 40 weight syn for the winter, but we'll see!
I use Pennzoil Platinum 5w-40 European and I have no issues. I drive 95% highway and do at least 100 miles a day. I need to find a good 5w-40 can buy off the shelves... Pennzoil but it is hard to find.
T6, Mobil 1 Turbo Diesel Truck, and M1's 0w40 are good choices for the boxer engine if you want to use a OTC syn. So is a 10/15w40 conventional in the summer. I have a thing for conventional oil in the subaru and run 40 weights in the summer. I'm thinking of sticking with a good 40 weight syn for the winter, but we'll see!
And for those wanting a heavier 30 weight, you can choose from High Mileage oils, straight 30w, GC, or Rotella T5 10w30. I'm predicting that Rotella T5 in 10w-40 is going to be a new darling of the Subie turbo crowd and outdoor power equipment, but don't tell anyone cause I won't be able to find any.
Originally Posted By: webfors
For what it's worth, I just changed the oil in my Forester to Rotella T 15w40 tonight. That's one smooth oil for the boxer.
I agree if you can find the T5 10w40 that would be a great choice!
So if I understand correctly a 15w40 will flow just fine during startup during the summer right? At what temp do you want to switch to a 0/5/10-40?
For what it's worth, I just changed the oil in my Forester to Rotella T 15w40 tonight. That's one smooth oil for the boxer.
I agree if you can find the T5 10w40 that would be a great choice!
So if I understand correctly a 15w40 will flow just fine during startup during the summer right? At what temp do you want to switch to a 0/5/10-40?
Originally Posted By: Unearthed
Originally Posted By: webfors
For what it's worth, I just changed the oil in my Forester to Rotella T 15w40 tonight. That's one smooth oil for the boxer.
I agree if you can find the T5 10w40 that would be a great choice!
So if I understand correctly a 15w40 will flow just fine during startup during the summer right? At what temp do you want to switch to a 0/5/10-40?
Right. I wouldn't run it when temps are approaching freezing. So I'll be changing this out in the fall, October - November.
Originally Posted By: webfors
For what it's worth, I just changed the oil in my Forester to Rotella T 15w40 tonight. That's one smooth oil for the boxer.
I agree if you can find the T5 10w40 that would be a great choice!
So if I understand correctly a 15w40 will flow just fine during startup during the summer right? At what temp do you want to switch to a 0/5/10-40?
Right. I wouldn't run it when temps are approaching freezing. So I'll be changing this out in the fall, October - November.
I've been running Mobil 1 Advanced Fuel Economy 0w30 in winter and Mobil 1 10w30 high mileage in summer with no problems at all. I got my best mpg ever with Mobil 1 0w-30, 34 mpg, '04 Subie Legacy 4 door.
Now that Mobil 1 5w30 high mileage is out, I'll be running that in the winter.
Now that Mobil 1 5w30 high mileage is out, I'll be running that in the winter.
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Originally Posted By: Unearthed
I am running Pennzoil Platinum 5w30 in it now and I have quite a bit of shake at idle. This is one of the reasons I was thinking of going to the 40wt.
I still have the shake but it is much less pronounced than the 30, I really do think it had to do with the variable cam on the exhaust but no proof for that.
Try it, you'll know right away. I recall it being a little louder at high rpm, now not so much.
I am running Pennzoil Platinum 5w30 in it now and I have quite a bit of shake at idle. This is one of the reasons I was thinking of going to the 40wt.
I still have the shake but it is much less pronounced than the 30, I really do think it had to do with the variable cam on the exhaust but no proof for that.
Try it, you'll know right away. I recall it being a little louder at high rpm, now not so much.
I changed out the PP today and put in Durablend 10w-40. It does seem quieter and smoother. This is surprising to me because I've never noticed a difference between oils before. I'm interested to see if this affects my mileage at all because I drive this car about 80% highway.
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