Turbo engines

[silverbullet]

Hi everybody.

I've recently purchased my first turbocharged car (2012 Subaru WRX). Being my first turbo, I wanted to learn about any special care for turbocharged engines by reading any and all information I could find (subaru manuals, tsb's, wrx and subaru specific forums and of course bitog).

My questions to the engine and oil experts here on bitog are:

Would the simple fact that an engine being turbocharged automatically categorize the engine use as "severe" instead of the "normal" use due the heat generated by the turbo?

Or would the actual driving conditions and habits still determine "severe" vs. "normal"?

My commute is as follows:

1) 25 miles each way to work (50 round trip)
2) 13 miles freeway @65-75mph and then 12 miles surface streets, stop and go @25-45mph.
3) Temperatures in my area ranges from 90-100+ deg. F in summer, 40-60+ deg. F winter, occasionally dipping into the mid to high 30s deg. F in the winter (Northern CA).
4) A/C in the summer of course.
5) No towing
6) All paved roads, no dirt roads or trails.
7) Typical road dust/dirt conditions you would see in the suburbs.

Would you categorize my commute as severe or normal use? Again, this is on a 2012 WRX (2.5L, H4, turbocharged and intercooled).

Thanks for the advice.

 

[accent2012]

Stop and go traffic kinda/sorta puts you into the severe category.

Play it safe and use good quality oil in that car.

 

[silverbullet]

That is my feeling as well.

And yes, I plan on using a quality oil. Per Subaru, it requires synthetic 5w30 (changed at 3750 miles for severe, 7500 miles normal). More specifically, I plan on running QSUD 5w30 mainly due to the GM 4718M corvette spec and the Honda HTO-06 spec for turbocharged engines. I was just trying to determine my OCI, which for now will be every 3750 miles.

 

[supton]

I'm no expert, but I disagree. It's not as if someone else slapped a turbo onto the motor; the manufacturer did, and has to stay behind the warrenty. Just because it is "turbo" doesn't mean it's "severe" usage. Harder on oil, yes; but that's why they wanted synthetic in the first place. The synthetic is going to handle the extra heat.

If it's of any interest, my turbo just died. 259kmiles, with 10k OCI's for the first 100kmiles; and 12k (sometimes 14k) OCI's since then. High quality synthetics the whole time. No city driving granted; but not driven lightly either. I haven't seen the carnage yet, but supposedly the nut backed off on the compressor wheel--not sure if that means bearing damage, or if it was completely unrelated to any sort of oiling issues.

I'd probably go 5k if it was my car, then towards the 7.5k. How long do you plan to keep it?

 

[lexus114]

The Subaru guy`s here say the boxer motor likes a heavier oil.

 

[MinusPrevious]

Weekend track day turbo guy here. Details in my sig.

 

[volk06]

You have a good plan. QSUD is the best everyday priced full syn. You made a wise choice looking for an oil with the hto6 spec. Some will say use conventional at 3750 oci but having a TGDI as well, full syns are more stable in high temp applications. HTO-6 approved oils are proven to resist degradation and prevent deposits. I've never seen a conventional or syn blend meet that spec fwiw.

 

[silverbullet]

I plan on keeping the car as long as it's running. And I plan to do my due diligence in keeping up with the maintenance by doing the routine maintenance items myself.

 

[accent2012]

Run a few UOAs on different brands of oil that meet that Honda spec to see which one might allow you to go beyond 3750mile oci.

 

[tig1]

M1 5-30 would be my choice since it has the Honda turbo HTO-06 spec for high heat and low deposit. For now I would stay with the warranty requirement for OCI.

 

[Nickdfresh]

I'd use (5w30) Mobil 1 or any of the Pennzoil synthetics with the HTO-06 tag on it...

 

[Mitch Alsup]

Originally Posted By: silverbullet

1) 25 miles each way to work (50 round trip)
2) 13 miles freeway @65-75mph and then 12 miles surface streets, stop and go @25-45mph.


It is likely that the 25 mile commute takes about 20 minutes. This puts you right on the borderline of typical service, but probably still leaves you in the severe catagory. If there are any other short runs to (grocery, 7-11, bar,...) you remain in the severe catagory, but you shold be able to push your luck 1/2 way from severe to typical.

 

[JimPghPA]

Originally Posted By: lexus114
The Subaru guy`s here say the boxer motor likes a heavier oil.


Mobil 1 TDT 5W-40 ?

 

[JimPghPA]

From what I have read here on BITOG, some turbos are easy on oils and some are very rough on oils. One of the things to look at is what temperature does the turbo expose the oil to.

 

[JimPghPA]

There is also a concern about running some turbos dry just after an oil change during the brief time that the oil pump has air in it and the oil light normaly comes on for that first start after an oil change. I think from what I remember reading about such turbos, and that was a long time ago, there was something that could be done to prevent that short dry run of the turbo, but I do not remember what that was.

 

[dave1251]

Originally Posted By: JimPghPA
From what I have read here on BITOG, some turbos are easy on oils and some are very rough on oils. One of the things to look at is what temperature does the turbo expose the oil to.


I agree.
To the OP study up if you have any further questions ask.

 

[bluesubie]

supton has a point about a turbo not automatically being severe service. SoA actually dropped the automatic severe service for turbos requirement a couple of years ago. But I would never run a Resource Conserving oil in a Subaru turbo for over 3,750 miles.

Having said that, the Honda spec alone wouldn't convince me to use an oil. Heck, when I emailed Mobil1 asking for recommendations they didn't even recommend the 5W30 for my application (out of warranty, manual allows 10W-30/10W-40). Yeah, you'll have a clean turbo when you spin a bearing.

If you look around this forum, and several Subaru forums, most people run something more robust regardless of SoA's recommendations. There are a few guinea pigs, I mean pioneers,

showing some good uoa results on Pennzoil Ultra and Platinum. Then there are actually folks on some forums supplying "non-spec" German Castrol and Rotella T6 for a dealer oil change.

The only 5w30 API SM that I would run is one that meets ACEA A3 specs (or an HTHS of 3.5 or higher without the spec like Red Line) and there's only a handful. I've had good results with Motul Eco-nergy before but it's SL.

-Dennis

 

[Mitch Alsup]

Originally Posted By: Mitch Alsup
Originally Posted By: silverbullet

1) 25 miles each way to work (50 round trip)
2) 13 miles freeway @65-75mph and then 12 miles surface streets, stop and go @25-45mph.


It is likely that the 25 mile commute takes about 20 minutes. This puts you right on the borderline of typical service, but probably still leaves you in the severe catagory. If there are any other short runs to (grocery, 7-11, bar,...) you remain in the severe catagory, but you shold be able to push your luck 1/2 way from severe to typical.


I also want to add: as you come to the conclusion of a drive, take the last 5 minutes at low-to-moderate power outputs so that the oil and lack of hot exhaust gasses will allow the turbo to cool before you shut it off. If you cannot let the trubo cool in the last 5 minutes, let the car idle for a miniute to let the oil cool the turbo below the oilcoaking temperature before shutting the car off.

 

[silverbullet]

Blusubie, I have read many people running more robust oils such as Rotella T6. But it also seems that many who use it are just following the pack (and out of warranty). Not that that is a bad thing. However, it doesn't prove that an energy conserving 5w30 oil shearing down to a 20 weight provides insufficient engine protection. Sure I've seen some UOAs indicating the shearing down of the oil. It may or may not have correlated to increased wear numbers. But I have not heard/read of widespread engine failures (more specifically WRXs) that were directly related to the failure of the oil to provide adequate protection. More often than not, the WRX failures I have read fall into a few categories such as 1) modified engines beyond reasonable levels for stock internals, 2) improper tunes, 3) manufacturing defects (certain batch of 2009 WRX engines).

I respect everybody's choices in running a more robust oil and I'm not trying to change it. However, at this point I don't buy it. Considering there are many engines (Chevy LSX engines and Ford V6 ecoboost, as well as many other turbo Subie engines as examples) running on the recommended 5w30 oil, we would be hearing of failures left and right.

However, I am here to learn so if people can provide solid data, information I am open to reading it.

 

[vtdave]

A turbo engine is no longer automatically "severe service" according to Subaru. Sounds like you are on the bubble. Maybe try a 5k OCI with a good quality synthetic. There are some UOAs showing SN 5w30 oils staying in grade on these engines over 3-5k: specifically Pennzoil Ultra, Pennzoil Platinum and Mobil 1 ESP. I thought hard about those and then followed the herd to German Castrol. That's just a personal bias because I've used GC on Audi engines with much success, and we all love the products we already know.