Best Synthetic Oils for my New and Old Subarus?

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What are the best Synthetic Oils for my New and Old Subarus?

New member here, although over the years from time to time I’ve read and learned from this forum.

I just bought a new Subaru Forester with the 2.5L normally-aspirated (non-turbo) engine. It requires Synthetic 0w-20 oil. Because I’m a perfectionist, I’d like to make an informed choice based on objective data, on what brand oil to use. I plan to adhere to the manufacturer’s OCI and use the OEM filter, regardless.

For the last 30 years I’ve used Mobil 1 exclusively—on 4 vehicles totaling about 800,000 miles—and I’m satisfied, with no oil-related maintenance problems. Nonetheless, I’m willing to open my eyes to consider other alternatives, if there is something that is objectively better and reasonably cost-effective. In particular, I’d like to hear about other’s experiences with Pennzoil Platinum and Ultra in Subarus, and also with (or in comparison to) the Subaru-branded synthetic oil. I’m open to hear about other brands as well.

I also have an older ’99 Subaru Legacy GT wagon with 190k miles that is still in service. It uses 5w-30. I want to keep using synthetic oil, but perhaps it is time to switch to a high-mileage type. (Up to now, I have used only the regular Mobil 1, not the HM variant). The car has started to use a little more oil, maybe a third or half quart per 1000 miles. I suspect the Subaru “usual suspect” seals. (leading to the joke “If your Subaru isn’t leaking oil, it just means that there isn’t any left in it”, LOL)

My forum search skills may be lacking, but I haven’t seen any specific VOA comparing the Subaru-branded synthetic against competing brands. Has anyone looked at this? But of course I know that UOA are even more important, and I’d like to hear what others have found on those too.

Typical use for both vehicles are a few trips into town each week, 20 miles each way from rural (dusty road) location and then a few stops in town a few miles apart, plus the occasional long trip a few times per year. My wife and I split the driving on each vehicle. I drive fairly gently/ defensively anticipating lights etc., my wife is a little more lead-footed.

Thanks in advance for any advice!
 
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For the old one, Mobil 1 High Mileage 5w30, one of the best choices you can make, and very few that are synthetic with extra seal conditioners. Valvoline Maxlife synthetic is the second choice.

You really can't go wrong with any of the name brand 0w20s, one of the most popular is Mobil 1.
 
There is no "best" oil. Non-turbo Subarus are easy on oil (not so sure about the new chain driven ones though), so any synthetic oil will do. If you prefer M1, use it because it consitently puts up excellent test results.

In the past, Valvoline full synthetic (both regular syn, and MaxLife) were the smoothest running oils in my Subaru. But again, use what you prefer.
 
A good place to start for your 0W20 research might be this PQIA summary that another BITOG poster pointed out not long ago...doesn't have nearly as many oils as their 5W30 page, unfortunately.
http://www.pqiamerica.com/June 2014/consolidated 0W-20.html
From that group, M1 looks pretty good all around and I like the NOACK and cold viscosity in particular. Castrol crushes it for TBN, though, suggesting you could probably change that brand less often than M1. This list doesn't have Pennzoil Platinum, unfortunately...in the 5W30 grade it looked quite similar to QSUD, but I don't know if that would apply to 0W20.

I don't know much at all about HM oils, I'm sure others here will have lots to say.
 
All about the same. If you want to save money, Kendall GT-1 0W20. Has a Titanium additive that my Subaru likes. I recently switched from Kendall GT-1 Syn Blend to Motorcraft Syn Blend (same base oils different additive packages) both are made by Conoco Phillips. I've lost 0.5mpg on the avg mpg readout since going to Motorcraft, which does NOT have the slippery titanium additive.
 
Mobil 1 0W20 is fine in the Forester, but I wouldn't bother with synthetic in the Legacy unless you intend to go beyond 7,500 miles on the oil. I'd run Mobil Super HM in the LGT, unless you absolutely want to run synthetic in it just for the warm and fuzzy feeling it will give you, then go with M1 HM.

I just sold a 2000 Impreza RS that had 165k miles on it and used Max Life blend right after I bought it at 60k miles. After some time on that, I switched to Pennzoil High Mileage conventional and the car liked it better. I know it liked it better because it told me.
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New subaru- get oil changes done at dealership with their oil with documentation. If the consumption issue is not a factor for you then use the others advice.

Old subaru- I have a 2001 with nearly 400000 miles using only what was on sale at the time, usually 5w30 usually at 5000 mile intervals or greater. If u havent had head gasket issues yet I would save money up for that job when it comes.
 
Welcome to BITOG. I have used M1 oils for 37 years and have never had a problem with engines showing signs of wear. All engines have remained very clean and I do 10K OCIs.
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Originally Posted By: Jack_Kieran
What are the best Synthetic Oils for my New and Old Subarus?

New member here, although over the years from time to time I’ve read and learned from this forum.

I just bought a new Subaru Forester with the 2.5L normally-aspirated (non-turbo) engine. It requires Synthetic 0w-20 oil. Because I’m a perfectionist, I’d like to make an informed choice based on objective data, on what brand oil to use. I plan to adhere to the manufacturer’s OCI and use the OEM filter, regardless.

For the last 30 years I’ve used Mobil 1 exclusively—on 4 vehicles totaling about 800,000 miles—and I’m satisfied, with no oil-related maintenance problems. Nonetheless, I’m willing to open my eyes to consider other alternatives, if there is something that is objectively better and reasonably cost-effective. In particular, I’d like to hear about other’s experiences with Pennzoil Platinum and Ultra in Subarus, and also with (or in comparison to) the Subaru-branded synthetic oil. I’m open to hear about other brands as well.

I also have an older ’99 Subaru Legacy GT wagon with 190k miles that is still in service. It uses 5w-30. I want to keep using synthetic oil, but perhaps it is time to switch to a high-mileage type. (Up to now, I have used only the regular Mobil 1, not the HM variant). The car has started to use a little more oil, maybe a third or half quart per 1000 miles. I suspect the Subaru “usual suspect” seals. (leading to the joke “If your Subaru isn’t leaking oil, it just means that there isn’t any left in it”, LOL)

My forum search skills may be lacking, but I haven’t seen any specific VOA comparing the Subaru-branded synthetic against competing brands. Has anyone looked at this? But of course I know that UOA are even more important, and I’d like to hear what others have found on those too.

Typical use for both vehicles are a few trips into town each week, 20 miles each way from rural (dusty road) location and then a few stops in town a few miles apart, plus the occasional long trip a few times per year. My wife and I split the driving on each vehicle. I drive fairly gently/ defensively anticipating lights etc., my wife is a little more lead-footed.

Thanks in advance for any advice!


OK, I have a '14 with 0w20 and a '99 Legacy OB (same 2.5 as your GT as the that GT year was only different from the OB with its suspension package).

Anyway, you can hunt down some UOA for each respective engine whether it is the EJ or the FB. Subaru-branded oil is going tough as it is not as much of a darling among Subaru/Oil folks. It is a good if slightly average Syn (harder to justify the dealer price-point).

My '99 OB does not consume oil an has 210K miles on it now. Actually, it uses less than the '14. I change it every 6 months which means I get about 3-5K miles off of it. As for oil, I use whatever is on sale. Right now I blend Quaker State Defy 5w20 and Shell T5 10w40 so make something akin to 5w30. Why? Each was $5 Per Jug. Otherwise, I use Havoline and have never had an oil-related problem. I might swap to Pennzoil for the 0w20 as the 0w20 Havoline is tough to find and the online price is going above $6 per qt... so the cost savings is not there. I have a sample of Havoline 0w20 that I need to send into blackwell. We will see when I get around to it.

M1 is fine, so keep using it if it makes you happy. However, other oils are more than fine for you application. I know that is not objective data but the difference between the major oils is so small, it becomes a wash at the end. Actually, NAPA Syn is one of the sleeping better oils (nearly identical to Valvoline SynPower, vanilla Royal Purple.

The Shell T5/T6 is more popular for the turbo crowds and isn't necessary but I will buy anything for $1 per quart.
 
I had 8 subarus. Pennzoil HM 5w30 bronze bottle for the older one (absolutely no need for synthetic here! and you'll find absolutely NO benefits from running it) and Ive had really good luck and a clean running and no sticky TC tensioner with Valvoline synpower 0w20. (Less so with their 5w20 for ?? reason). On the FB25 I've run: Subaru idemitsu 0w20, M1, QSUD and the VSP. VSP for good results!
Ive had two FB25 so far!
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Originally Posted By: krismoriah72

Old subaru- I have a 2001 with nearly 400000 miles using only what was on sale at the time, usually 5w30 usually at 5000 mile intervals or greater. If u havent had head gasket issues yet I would save money up for that job when it comes.



400K miles is a great case study, I hope I get that from my '09 EJ25!

Have you had head gasket failures more than once over this time period, or no further failures after the factory gaskets were replaced?
 
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