Rotella T6 5W30?

Yes, its technically a diesel oil but because its high in zync content it's good for our turbos!

Run this or others like motul and amsoil. Always use an OEM subaru filter though.

-Brian

Yup 5w40, it has a high zinc/ZDDP content which helps protect from engine wear.

The EJ series motors are an older design, dating back to the 80's, they run looser tolerances than modern engines and usually do better with thicker oil - the caveat to that is lower fuel efficiency with thicker oil. Subaru states 5w30 mainly for that reason.

Is there a detectable difference in an oil that's 10wt thicker? I've always run T6 5w-40 in all the turbo vehicles I've owned. Would there be a measurable increase in fuel economy going to a 5w 30 I wonder?

for EPA duty cycle testing, probably. For real world economy? How heavy your right foot is would matter more.

Is there a detectable difference in an oil that's 10wt thicker? I've always run T6 5w-40 in all the turbo vehicles I've owned. Would there be a measurable increase in fuel economy going to a 5w 30 I wonder?

I have run both 5w30 and 5w40, no detectable difference. Mostly because I floor it at every opportunity.

Go with the 40wt, it will have a higher HTHS. I talked about HTHS in the thread below.

http://legacygt.com/forums/showthread.php/rotella-t6-zinc-decrease-250562.html

I was going back and forth about whether or not to reply to this again, since it's such a complex subject. Here are a few additional thoughts though. I don't think the reason why rotella does so well in turbo subies is because of the extra ZDDP. I think the main reason rotella does so well is because it has a fairly high HTHS value. Shell does not publish the HTHS number for rotella t6 5w-40, but based off some of the certifications it meets, it is thought to be at least 3.8 mPa•s.

 

So what is HTHS? HTHS is sort of like the film thickness of the oil on moving parts. Lower HTHS is great for fuel economy, but higher HTHS values are better for engine protection.

http://www.hddeo.com/hthsarticle.html

 

For comparison sake, here's the HTHS of a few oils. One thing to note is last I knew, the minimum allowable HTHS of an oil was 2.6, mostly seen in 0w-20 oils. Note that 5w-40 and 0w-40 oils will generally have a higher HTHS value than a 5w-30 or 0w-30 oil.

 

Rotella T6 5w-40 – Suspected at least 3.8 mPa•s, because of some of the certiifications it meets.

Mobil 1 5w-30 – 3.1 mPa•s.

Mobil 1 10w-30 – 3.0 mPa•s.

Mobil 1 0w-40 – 3.8 mPa•s.

Mobil 1 Turbo Diesel Truck 5w-40 – 3.8 mPa•s.

 

Castrol Edge 5w-30 – At least 3.5 due to ACEA C3 spec

Pennzoil Platinum and Ultra Platinum 5w-30 – Between 2.9 – 3.5 mPa•s. due to ACEA A5 spec

Pennzoil Platinum Euro 5w-40 – At least 3.5 mPa•s. due to the ACEA A3 spec

 

Amsoil Signature 5w-30 – 3.1 mPa•s.

Amsoil XL and OE 5w-30 – 3.3 mPa•s.

Amsoil European car formula 5w-30 – 3.6 mPa•s.

Amsoil European car forumula 5w-40 – 3.7 mPa•s.

 

Red Line 5w-30 – 3.7 mPa•s.

Red Line 5w-40 – 4.4 mPa•s.

 

Castrol, Pennzoil, Havoline and Valvoline don't publish their HTHS values on their product/technical data sheets, so that's why the list is a bit limited. When I look at the list above, there is probably a difference of at least .8-.9 mPa•s between Mobil 1 5w-30 and Rotella T6 5w-40, so that might help explain why some people don't like Mobil 1 in their turbo subaru's. .8 - .9 might not sound like much, but when you consider the tight range of 2.6 - 4.4 mPa•s mentioned above, it is a pretty big step up in my opinion.

 

High amounts of ZDDP is just one aspect of an oil like Rotella. I was very active on bitog from 2004-2009. During that time, two things were very popular, high molybdenum oils and German Castrol. The funny thing is, German Castrol had 0 ppm of molybdenum in it. So what I'm trying to say is, there are many different ways to formulate a quality oil. If shell reduced the ZDDP, maybe they boosted other additives to make up for that. You can't just focus on one aspect of a motor oil, even something like HTHS like I've talked about here.

 

Couple articles that talk about HTHS and ZDDP.

http://www.redlineoil.com/news_article.aspx?id=291

 

The article below mentions that HTHS is important, but the additive package is very important as well, which is true. But again, there are other additives out there aside from ZDDP which can help reduce wear.

http://viewer.zmags.com/publication/d4e8e0b9#/d4e8e0b9/16

part 2

http://viewer.zmags.com/publication/20213322#/20213322/49

 

http://www.amsoil.com/newsstand/classic-and-vintage/articles/flat-tappet-cams-in-classic-cars/

I can't remember the dates on the product data sheets from when I posted that, but they weren't too old. It looks like the 0w-40 HTHS has dropped from 3.8 to 3.6.

Mobil 1 HTHS

0w-40 - 3.6

5w-30 - 3.1

10w-30 - 3.0

5w-50 - 4.4

Should you break in a rebuilt motor on this oil?

Most say no. It's to slippery and the rings will have a hard time seating.

Use a good dino oil and change it and filter after 20 minutes of run time to get all the rebuild lube out.

Then after 500 miles, then after another 1000 miles, then after another 1500 miles. then you can use synthetic.

Most say no. It's to slippery and the rings will have a hard time seating.

 

Use a good dino oil and change it and filter after 20 minutes of run time to get all the rebuild lube out.

 

Then after 500 miles, then after another 1000 miles, then after another 1500 miles. then you can use synthetic.

So pretty much skip the Amsoil break in oil for that 1st 20 minute run and done session? Since we are already in this boat and JmP clearly states no Mobil 1 in his turbo builds(and I don't blame him), whats a good selection of good dino oils?

So pretty much skip the Amsoil break in oil for that 1st 20 minute run and done session? Since we are already in this boat and JmP clearly states no Mobil 1 in his turbo builds(and I don't blame him), whats a good selection of good dino oils?

Really, any name brand dino oil. FWIW, I ran what ever 5w-30 was on sale at Walmart for the first 154,000 miles in my wagon also used Fram filters. Never had a engine bearing problem, the turbo lasted 142,000 miles.

I used Castrol GTX 5w-30 as my break in oil. I think most know I use Amsoil 5w-40 European Full SAPS and their filters and do 7000 miles OCI since that 3000 mile oil change back about 4 years ago.

10w-30 blend rotella or delo works good for me only problem I'm having is an oil leak before I realized the leak was there it was down to 2qts and motor held strong

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I always hear lots of people talking about using Rotella T6, so I was thinking maybe I should consider switching to that. But I'm having trouble finding it in 5W30. I see a ton of 5W40. Do we use Rotella T6 5W40 in our cars?

I would definitely prefer 5W40 over 5W30 since it's a better oil grade range.

Also see this thread: http://legacygt.com/forums/showthread.php/clearing-up-all-oil-info-79800.html

If you really want to stick to the 30 grade look for a 0W30 instead.

I run Rotella T6 in 5 of our vehicles here... outback 3.6R, 08 spec b, 02 wrx, 07 honda vfr, bmw s1000r... best oil for the money IMO. If money was not a factor, Id be putting in redline, motul, amsoil, in that order of preference.

Here is a really good thread if you want to learn a lot more about oil: http://forums.nasioc.com/forums/showthread.php?t=2714154

I would definitely prefer 5W40 over 5W30 since it's a better oil grade range.

 

Also see this thread: http://legacygt.com/forums/showthread.php/clearing-up-all-oil-info-79800.html

 

If you really want to stick to the 30 grade look for a 0W30 instead.

0W 30 is what I used, Mobil 1 tho. Not doing that again.

While our manuals state 5w30, there's no reason not to have better performing oil.

The oil breaks down over time, so the initial viscosity rating does not hold over your oil change interval. Rotella T6 40 weight may shear to a 30 weight after a few thousand miles, and a 30 weight would break down into the 20s... which is great for gas mileage, but not so great for lubrication and reliability.

Regarding filters, the OEM blues used to be the way to go. But the last six pack I bought will be it for me. Each one of them has wept oil on both the Saabaru and LGT. They are now light and flimsy, too. Turns out they're no longer made by a quality company (now built by FRAM), so many of us have switched to the Mazda RX8 oil filter built by Tokyo Roki (previous makers of our old OEM blue filters). The part number is N3R1-14-302. These Mazda filters have the same bypass pressure as the Subaru units, they're better quality inside and out, and they are even a little taller. They also don't leak oil... always a plus

Regarding filters, the OEM blues used to be the way to go. But the last six pack I bought will be it for me. Each one of them has wept oil on both the Saabaru and LGT. They are now light and flimsy, too. Turns out they're no longer made by a quality company (now built by FRAM), so many of us have switched to the Mazda RX8 oil filter built by Tokyo Roki (previous makers of our old OEM blue filters). The part number is N3R1-14-302. These Mazda filters have the same bypass pressure as the Subaru units, they're better quality inside and out, and they are even a little taller. They also don't leak oil... always a plus

I have been using a Mobile 1 filter and Valvoline full synthetic 5w30 oil. While I've been in the process of replacing my turbo I've also been reading other threads on here. I'm stocked up on Rotella T6 now after this thread; thoughts on the Mobile 1 filter? Should I switch to the Mazda filter?