I drive a 2008 Mazdaspeed 3, a turbo charged 2.3L direct injected gasoline car. I have since heavily modified the car, but the point of this post is very simple: What is the BEST syn oil for this platform??
To give a little back story, these cars from the factory had a big problem with the turbo (K04) seals always going bad and eventually burning oil and dumping clouds of smoke. As people began to figure out the issue of why the smoke was happening (the turbo), cheap fixes were then implemented like oil restrictor bolts for the turbo, or just as popular, changing from the 5w30 to a 5w40 oil. That then became the norm for this platform. If you spend any time reading what oil to run on these cars, you will always find people telling you Rotella T6 as it's "great for this car because of the turbo and it's thicker which helps prevent the oil seeping past the seals in the turbo" etc etc. Well, that was years ago, today however still perpetuate the idea that T6 is the go-to oil for this car/platform. But I want to really get to the bottom of the ACTUAL best oil for this car excluding that turbo problem, because like many others, I have/will replace the turbo and go much bigger and indirectly not have to worry about bad seals on a good performance aftermarket turbo. I've been looking at some "lists of the best synthetic oils", on one particular list T6 ranked as low as the 130's, where as a mobil 1 5w30 ranked within the top 5-10!!! Yet people that have claimed to used this oil said their car ran worse using it. Everyone has their opinions, which makes it so [censored] hard to determine a great oil for this platform. Being disi+turbo throws a bit of a monkey wrench in it due to have limited this setup is used compared to so many others. So what works for others, may not and some literally don't work well for the disi+turbo motor.
I figured I'd come to "THE" place for oil questions and insight. So I ask the educated community of this forum, to please assist me in my quest to find a great oil for my car, especially since I've built the block and really want this motor to last (I wpc treated the block, pistons, rings, bearings). It will be high boost with Meth inject. so I want a good oil, just incase I'm making a mistake continuing to use Shell Rotella T6.
Thank you!
The great Oil problem that plagues turbo disi
- Thread starter Haxir
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I'd be looking at an A3/B4 oil... Something like M1 or Castrol 0W-40.
All the OE approvals they carry are relevant to long OCIs on small displacement turbocharged direct injected engines with variable valve timing.
You could pour one of those two oils in just about any engine and they'd perform admirably.
I'm not sure why Rotella T6 gets put on a pedestal as some catch all miracle product; it's really not.
Is this the engine that also suffers from the the timing chain rattle at start up and sludge issues?
Originally Posted By: GSCJR
Is this the engine that also suffers from the the timing chain rattle at start up and sludge issues?
M1 0w-40. Or the M1 HM 10w-30
Or the castrol 0w-40
If you're really beating on it consider something like M1 15w50 or the 5w-50
Any W something 30 something that is on sale. This week the winner maybe NAPA at $18.99 a Jug.
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Originally Posted By: SilverFusion2010
M1 0w-40. Or the M1 HM 10w-30
Or the castrol 0w-40
If you're really beating on it consider something like M1 15w50 or the 5w-50
Rotella T4 10W-30 or Rotella T5 Synblend 10W-30 have my vote. You can check out a UOA on T4 10W-30 posted recently. T4 10W-30 Used Oil Analysis
If you're feeling adventurous than Delo 400 Severe Duty 15W-30 has my vote. Nice and stout heavy duty, oil.
SAE Grade 15W-30
Product Number 224615
SDS Number 36110
Density at 15°C, kg/L 0.881
Viscosity, Kinematic:
cSt at 40°C 89.1
cSt at 100°C 12.0
Viscosity, MRV, °C/Poise -25/14,900
Viscosity, Cold Crank, °C/Poise -20/64.0
Viscosity Index 128
Flash Point, °C(°F) 233(451)
Pour Point, °C(°F) -36(-33)
Sulfated Ash, wt % 1.0
Base Number 9
Phosphorus, wt % 0.12 (1200ppm)
Sulfur, wt % 0.31
Zinc, wt % 0.12 (1200ppm)
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REDLINE OIL is what ya need, then run an upper cyn lube like SOY SHEILD by schaeffers. to keep fuel system happy and best oil for the turbo. YOU WILL SEE A DIFF.
Originally Posted By: fdcg27
Originally Posted By: JohnnyJohnson
Any W something 30 something that is on sale. This week the winner maybe NAPA at $18.99 a Jug.
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Don't give much credence to the list that gave the 130 ranking to T6. There are many better ways to rank oils (ie mfg certified testing, actual in use performance on driven/raced vehicles, etc.). If I recall correctly, M1 0w-40 is ranked near the very top of that same list....and it carries excellent mfg certs.
Okay. I know a lot about oil but my mechanical skills are bloody awful so you're going to have to help me to help you.
When you're designing an engine oil, you primarily design it for the crankcase; not the turbo. There are a couple of oil tests that notionally focus on turbo fouling (the TEOST MHT-4 for example) which all oils have to pass, but I personally would put zero faith in these to protect your turbo.
I haven't delved too deeply into turbo lubrication but I just had a quick squint at some YouTube videos and presumably the 'seals' that you're referring to are two metal split rings (like small piston rings) that sit in grooves on the turbo shaft. There's one on the outer side of the two shaft bearings (so one on the exhaust side and one on the intake side). If I've understood things correctly, it's the exhaust side split ring seal that's failing such that engine oil leaks into the exhaust and causes a lot of white smoke. If I have this wrong, please let me know.
Okay. So why might the seal be failing. I could see three possible oil related modes of failure.
1. The outer edge of the ring is wearing away. There is no 'ring wiping' in the way the outer edges of standard piston rings get lubricated so they may be inherently more prone to wear. I may be wrong but I suspect the only oil the seal outer edges get oiled is by oil 'leaking' (and getting distributed) through the gap in the split ring (?). I'm assuming that the exhaust side of the turbo runs significantly hotter than the inlet side. It could be that the diameter of the shaft on the exhaust side is slightly bigger (due to thermal expansion) which causes the seal ring to press harder against its bore surface. This would also exacerbated wear.
If outer surface wear in the root cause then IMO you need, first off, an oil that is high in ZDDP & Moly and a thicker oil second. This might be why people have gravitated to using HDDOs because these oils allow you to use more ZDDP. Also, given the speed of turbo shafts, you really need an oil that has very good High Temperature High Shear (HTHS) performance. For this you need a full synthetic (Group III or preferably PAO). Also you need a narrow cross-grade to minimise the amount of VII polymer to have in the oil. This means don't think in terms of 5W40s when a full synthetic 10W30 might be better.
2. The other possible failure mode is if oil related deposits build up in the groove that seats the exhaust side split ring. The top and second piston rings/grooves on a normal piston are self-cleaning. The seal and groove on a turbo shaft will not be as there is no reciprocating action. Deposit build up behind the seal will increase the force on the seal face and increase the rate of wear (same as above) but I might be more concerned about the deposits causing the seal to 'stick' flush in its groove, much the same way a piston's oil control ring can stick (and cause excessive oil consumption).
If this were true, then again it might explain why people have looked to HDDOs as a fix. HDDO will always contain a lot more Ashless Dispersant than PCMO and traditionally, Ashless is what to look to to reduce groove deposits.
I'll stop here and you can tell me if I'm on the right track or not. Like I said, I'm not the world's greatest mechanic so I might be way off the beam with my analysis of the problem.
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No, if you have a difficult turbo application like that I would run a 5W40 ester based oil like Motul Sport.
..."specially designed for high performance tuned turbo-charged..."
https://www.motul.com/us/en-US/products/sport-5w40
Originally Posted By: SonofJoe
Okay. I know a lot about oil but my mechanical skills are bloody awful so you're going to have to help me to help you.
When you're designing an engine oil, you primarily design it for the crankcase; not the turbo. There are a couple of oil tests that notionally focus on turbo fouling (the TEOST MHT-4 for example) which all oils have to pass, but I personally would put zero faith in these to protect your turbo.
I haven't delved too deeply into turbo lubrication but I just had a quick squint at some YouTube videos and presumably the 'seals' that you're referring to are two metal split rings (like small piston rings) that sit in grooves on the turbo shaft. There's one on the outer side of the two shaft bearings (so one on the exhaust side and one on the intake side). If I've understood things correctly, it's the exhaust side split ring seal that's failing such that engine oil leaks into the exhaust and causes a lot of white smoke. If I have this wrong, please let me know.
Okay. So why might the seal be failing. I could see three possible oil related modes of failure.
1. The outer edge of the ring is wearing away. There is no 'ring wiping' in the way the outer edges of standard piston rings get lubricated so they may be inherently more prone to wear. I may be wrong but I suspect the only oil the seal outer edges get oiled is by oil 'leaking' (and getting distributed) through the gap in the split ring (?). I'm assuming that the exhaust side of the turbo runs significantly hotter than the inlet side. It could be that the diameter of the shaft on the exhaust side is slightly bigger (due to thermal expansion) which causes the seal ring to press harder against its bore surface. This would also exacerbated wear.
If outer surface wear in the root cause then IMO you need, first off, an oil that is high in ZDDP & Moly and a thicker oil second. This might be why people have gravitated to using HDDOs because these oils allow you to use more ZDDP. Also, given the speed of turbo shafts, you really need an oil that has very good High Temperature High Shear (HTHS) performance. For this you need a full synthetic (Group III or preferably PAO). Also you need a narrow cross-grade to minimise the amount of VII polymer to have in the oil. This means don't think in terms of 5W40s when a full synthetic 10W30 might be better.
2. The other possible failure mode is if oil related deposits build up in the groove that seats the exhaust side split ring. The top and second piston rings/grooves on a normal piston are self-cleaning. The seal and groove on a turbo shaft will not be as there is no reciprocating action. Deposit build up behind the seal will increase the force on the seal face and increase the rate of wear (same as above) but I might be more concerned about the deposits causing the seal to 'stick' flush in its groove, much the same way a piston's oil control ring can stick (and cause excessive oil consumption).
If this were true, then again it might explain why people have looked to HDDOs as a fix. HDDO will always contain a lot more Ashless Dispersant than PCMO and traditionally, Ashless is what to look to to reduce groove deposits.
I'll stop here and you can tell me if I'm on the right track or not. Like I said, I'm not the world's greatest mechanic so I might be way off the beam with my analysis of the problem.
Since it's the one I thought it was, I second what rooflessvw suggested.
Everyone has their own 'best oil' (Shell helix Ultra since you asked, AKA: Pennzoil platinum in N.A, since it's the only oil with a single source of base oil. The Pearl GTL plant)
Now in your case,
- -Ensuring that the turbocharger is receiving the correct oil pressure and volume is important. -Ensuring that the oil is kept clean (regular change with filter) -Avoid hard shutdowns with the turbo glowing red hot (or you'll coke oil in the bearing housing, which becomes grit, which flogs out seals and bearings) -Possibly using an oil cooler, but definitely get an oil temp gauge if you plan on beating on this engine at a race circuit. -Etc...
Originally Posted By: JFAllen
Everyone has their own 'best oil' (Shell helix Ultra since you asked, AKA: Pennzoil platinum in N.A, since it's the only oil with a single source of base oil. The Pearl GTL plant)
Now in your case,
- -Ensuring that the turbocharger is receiving the correct oil pressure and volume is important. -Ensuring that the oil is kept clean (regular change with filter) -Avoid hard shutdowns with the turbo glowing red hot (or you'll coke oil in the bearing housing, which becomes grit, which flogs out seals and bearings) -Possibly using an oil cooler, but definitely get an oil temp gauge if you plan on beating on this engine at a race circuit. -Etc...
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