If you drove it like a Prius, easy on the gas, then the 5-30 would be fine. But try a thicker oil, couldn't hurt might help.
Penzoil 5w-30 high mileage, 6000mi, 02 Subaru WRX
- Thread starter awns729
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Originally Posted By: awns729
Originally Posted By: bluesubie
Originally Posted By: oaklandish_wrx
Possibly the only reason his sample still reads as a 30 - eeek!
And start engine/re-builder shopping. 1 quart/1K is INSANE.
OP - Not sure where you are in NY, but you might want to check out EFI Logics in CT or Performance Auto Solutions on Long Island. You can't get much better than either of those in NY, Northern NJ, or LI.
I would probably go with M1 10W40 High Mileage since it's a little thicker than RT6. Either is better than what you're running though.
Yep, there's also The Shop in Norwalk, CT and Prime Motoring in NJ, both of which I've heard good things about. Not sure if Prime does rebuilds though. I'll keep EFI in mind as well. Thanks for the suggestions
Are these wear numbers really that bad that it's a definite rebuild coming soon? Even if switching oils lowers the wear to reasonable levels now?
Also, can anyone provide me with threads/articles that cover why these higher viscosity oils are recommended? I thought that startup wear was always a factor in picking oil, and a 5W-40 has a higher cold viscosity than a 5W-30 and therefore will cause more wear on startup. Seems like, whether true or not, that's not really relevant to turbo engines, since everyone's suggesting Rotella T6/M1 10W40, which I'm happy to try, but I'd love some more "scientific" reading as to why. Searching didn't turn up much - mostly just "switch to rotella T6 BEACAUSE" type threads lol
Thanks for the help!
Your turbo runs hot will destroy cheap conventional 5w-30. I don't have time right now to provide links, but there's a lot of information on this and turbo failures over at NASIOC.
Originally Posted By: bluesubie
Originally Posted By: oaklandish_wrx
Possibly the only reason his sample still reads as a 30 - eeek!
And start engine/re-builder shopping. 1 quart/1K is INSANE.
OP - Not sure where you are in NY, but you might want to check out EFI Logics in CT or Performance Auto Solutions on Long Island. You can't get much better than either of those in NY, Northern NJ, or LI.
I would probably go with M1 10W40 High Mileage since it's a little thicker than RT6. Either is better than what you're running though.
Yep, there's also The Shop in Norwalk, CT and Prime Motoring in NJ, both of which I've heard good things about. Not sure if Prime does rebuilds though. I'll keep EFI in mind as well. Thanks for the suggestions
Are these wear numbers really that bad that it's a definite rebuild coming soon? Even if switching oils lowers the wear to reasonable levels now?
Also, can anyone provide me with threads/articles that cover why these higher viscosity oils are recommended? I thought that startup wear was always a factor in picking oil, and a 5W-40 has a higher cold viscosity than a 5W-30 and therefore will cause more wear on startup. Seems like, whether true or not, that's not really relevant to turbo engines, since everyone's suggesting Rotella T6/M1 10W40, which I'm happy to try, but I'd love some more "scientific" reading as to why. Searching didn't turn up much - mostly just "switch to rotella T6 BEACAUSE" type threads lol
Thanks for the help!
Your turbo runs hot will destroy cheap conventional 5w-30. I don't have time right now to provide links, but there's a lot of information on this and turbo failures over at NASIOC.
Yes, the Shop in CT is very good as well.
A good place to read about thicker oil use in WRX's, other than those of us that have had experience with them for 14 years
, is the Oil Selection Guide sticky at nasioc. Another good place is your owner's manual. It recommends thicker oil in severe conditions and allows 10W-40 down to -4F. Your oil cap shows the "preferred" viscosity for fuel economy for an unmodified car driven in ideal conditions.
If you don't have a manual, you can access one at subaru.com:
http://techinfo.subaru.com/proxy/69553/pdf/ownerManual/069553_2003_ImprezaWRX/MSA5M0303A_18.pdf
See pages 11-14 and 11-15.
Edit: I linked the 2003 manual but it's the same.
A good place to read about thicker oil use in WRX's, other than those of us that have had experience with them for 14 years
If you don't have a manual, you can access one at subaru.com:
http://techinfo.subaru.com/proxy/69553/pdf/ownerManual/069553_2003_ImprezaWRX/MSA5M0303A_18.pdf
See pages 11-14 and 11-15.
Edit: I linked the 2003 manual but it's the same.
Last edited:
If it was my vehicle, I would try Mobil 1 10W40 HM oil and also replace the PCV again. I know guys that recommend PCV replacement every 15K-30K depending on the vehicle...
Originally Posted By: bluesubie
Yes, the Shop in CT is very good as well.
A good place to read about thicker oil use in WRX's, other than those of us that have had experience with them for 14 years
, is the Oil Selection Guide sticky at nasioc. Another good place is your owner's manual. It recommends thicker oil in severe conditions and allows 10W-40 down to -4F. Your oil cap shows the "preferred" viscosity for fuel economy for an unmodified car driven in ideal conditions.
If you don't have a manual, you can access one at subaru.com:
http://techinfo.subaru.com/proxy/69553/pdf/ownerManual/069553_2003_ImprezaWRX/MSA5M0303A_18.pdf
See pages 11-14 and 11-15.
Edit: I linked the 2003 manual but it's the same.
Thanks! The NASIOC oil selection guide helped clear some stuff up for me, along with some of the links it points to. Previously, my main source of info was the motor oil 101-109 guide here at BITOG, and after reading that, I didn't do much research, but now I realize I should have read from multiple sources. I had (and still have) some questions because I'm trying to reconcile the information in the motor oil articles on BITOG ("Motor Oil Univeristy") with everyone's suggestions for higher viscosity oils.
The author of the motor oil articles discusses how oil is much better being too thin than too thick.
Quote:
I truly believe that oil is much better being too thin than too thick. Over the years we have been going to thinner and thinner oils despite hotter engines with turbos and the like. The tendency is that people figure they need a 40 grade oils but then use a 50 instead. Better thinking is that if you think you need a 40, use a 30 grade oil instead. I firmly believe this based on all I know about oils.
He goes on to mention that a thinner oil reduced temperature but not pressure during racing:
Quote:
One of the members of the Ferrari Chat web site went from a 40 to a 30 grade oil in his Ferrari 355 for racing in Texas. He noticed a drop in temperature but no change in oil pressure. This may seem odd but really makes perfect sense. Since the 30 grade oil is thinner he got better flow and therefore better cooling. The oil was at a lower temperature so it was not as thin than it would have been at the previous higher temperature. Cooler engines last longer. Fact: The higher the temperature, the greater the wear, all other things being equal.
And continues that older engines benefit from thinner oil:
Quote:
Older engines may in fact benefit from thinner oil use. Over time permanent deposits of carbon and sludge build up in the engine oil ways. It is like a clogging of arteries in humans. We are now all on blood thinners. This is an area I specifically studied while a general surgeon resident at Chapel Hill.
And I never understood why people are running a 5W-40, since that will have a higher cold viscosity than a 5W-30 (AFAIK), and most engine wear happens at startup:
Quote:
I thought everyone knew that 90 percent of engine wear occurs during the startup period because oil is just too thick. Some think it is good to have a thicker oil for startup since the parts shrink when cold and would otherwise “rattle.” Sure, your piston diameter will shrink on cooling but so will the diameter of your bore. The net result is about the same clearance hot and cold. This is not true for your valves. They lengthen when extremely hot. In the Murcielago they use shims instead of self adjusting valve tappets. You need to put a millimeter of clearance there so that after expansion the valve will not be held partly open when it is supposed to be closed.
This line also made me think that a higher viscosity oil was counter productive:
Quote:
Increasing the pressure while using the same oil will increase the oil flow but increasing the pressure by increasing the oil thickness will result in less flow. It takes more pressure to move a thicker oil. When you go to a thicker oil the pressure goes up because of the increased resistance, and therefore reduction of flow. Because the pressure is higher sooner, the relief valve cuts in sooner. Flow will actually be less when the RPM is up and the flow is needed the most.
The author goes on to show an example of a thinner oil vs. a thicker oil at a given RPM. The thicker oil flows less at a given pressure than the thinner oil causing the overall flow rate to be reduced. I think this is because, in his example, the thicker oil's pressure causes the relief valve to open sooner. Since the thicker oil produced more pressure at the same flow rate as the thinner oil, the thicker oil will result in the relief valve opening sooner at a lower flow rate than the thinner oil.
But I'm beginning to believe that this really isn't the full picture. Seems like T6/M1 (or any similar synthetic) would have the following benefits over the conventional that I was running:
Better flow characteristics at startup, actually resulting in less startup wear.
It was mentioned that my 5w-30 was a relatively lower viscosity at operating temperature (9.6cSt most recently and the first few samples were < 9cSt!). Someone mentioned this was close to a 20 grade oil. I'd imagine that since the viscosity is a bit low, bringing it closer to (or in) the mixed-film lubrication section of the Stribeck curve, this is potentially a reason for my increased wear rates. Switching to the higher viscosity oil keeps the engine more to the right on the curve, and I'd imagine the 10w-40 mobile 1 would be even more to the right. The only down side being higher friction, but due to fluid friction, not metal-to-metal contact. But the increased friction is worth the safety net, and it doesn't harm the engine - maybe just gas mileage slightly.
Am I on the right track here? I've switched to T6 already and am planning on trying out the M1 10W-40 suggestion next time. I also, for my own sake, want to understand why these suggestions were given. I think I kind of get why T6 was suggested but am less clear on M1, since its a 10W grade. I appreciate the help so far!
Yes, the Shop in CT is very good as well.
A good place to read about thicker oil use in WRX's, other than those of us that have had experience with them for 14 years
If you don't have a manual, you can access one at subaru.com:
http://techinfo.subaru.com/proxy/69553/pdf/ownerManual/069553_2003_ImprezaWRX/MSA5M0303A_18.pdf
See pages 11-14 and 11-15.
Edit: I linked the 2003 manual but it's the same.
Thanks! The NASIOC oil selection guide helped clear some stuff up for me, along with some of the links it points to. Previously, my main source of info was the motor oil 101-109 guide here at BITOG, and after reading that, I didn't do much research, but now I realize I should have read from multiple sources. I had (and still have) some questions because I'm trying to reconcile the information in the motor oil articles on BITOG ("Motor Oil Univeristy") with everyone's suggestions for higher viscosity oils.
The author of the motor oil articles discusses how oil is much better being too thin than too thick.
Quote:
I truly believe that oil is much better being too thin than too thick. Over the years we have been going to thinner and thinner oils despite hotter engines with turbos and the like. The tendency is that people figure they need a 40 grade oils but then use a 50 instead. Better thinking is that if you think you need a 40, use a 30 grade oil instead. I firmly believe this based on all I know about oils.
He goes on to mention that a thinner oil reduced temperature but not pressure during racing:
Quote:
One of the members of the Ferrari Chat web site went from a 40 to a 30 grade oil in his Ferrari 355 for racing in Texas. He noticed a drop in temperature but no change in oil pressure. This may seem odd but really makes perfect sense. Since the 30 grade oil is thinner he got better flow and therefore better cooling. The oil was at a lower temperature so it was not as thin than it would have been at the previous higher temperature. Cooler engines last longer. Fact: The higher the temperature, the greater the wear, all other things being equal.
And continues that older engines benefit from thinner oil:
Quote:
Older engines may in fact benefit from thinner oil use. Over time permanent deposits of carbon and sludge build up in the engine oil ways. It is like a clogging of arteries in humans. We are now all on blood thinners. This is an area I specifically studied while a general surgeon resident at Chapel Hill.
And I never understood why people are running a 5W-40, since that will have a higher cold viscosity than a 5W-30 (AFAIK), and most engine wear happens at startup:
Quote:
I thought everyone knew that 90 percent of engine wear occurs during the startup period because oil is just too thick. Some think it is good to have a thicker oil for startup since the parts shrink when cold and would otherwise “rattle.” Sure, your piston diameter will shrink on cooling but so will the diameter of your bore. The net result is about the same clearance hot and cold. This is not true for your valves. They lengthen when extremely hot. In the Murcielago they use shims instead of self adjusting valve tappets. You need to put a millimeter of clearance there so that after expansion the valve will not be held partly open when it is supposed to be closed.
This line also made me think that a higher viscosity oil was counter productive:
Quote:
Increasing the pressure while using the same oil will increase the oil flow but increasing the pressure by increasing the oil thickness will result in less flow. It takes more pressure to move a thicker oil. When you go to a thicker oil the pressure goes up because of the increased resistance, and therefore reduction of flow. Because the pressure is higher sooner, the relief valve cuts in sooner. Flow will actually be less when the RPM is up and the flow is needed the most.
The author goes on to show an example of a thinner oil vs. a thicker oil at a given RPM. The thicker oil flows less at a given pressure than the thinner oil causing the overall flow rate to be reduced. I think this is because, in his example, the thicker oil's pressure causes the relief valve to open sooner. Since the thicker oil produced more pressure at the same flow rate as the thinner oil, the thicker oil will result in the relief valve opening sooner at a lower flow rate than the thinner oil.
But I'm beginning to believe that this really isn't the full picture. Seems like T6/M1 (or any similar synthetic) would have the following benefits over the conventional that I was running:
Better flow characteristics at startup, actually resulting in less startup wear.
It was mentioned that my 5w-30 was a relatively lower viscosity at operating temperature (9.6cSt most recently and the first few samples were < 9cSt!). Someone mentioned this was close to a 20 grade oil. I'd imagine that since the viscosity is a bit low, bringing it closer to (or in) the mixed-film lubrication section of the Stribeck curve, this is potentially a reason for my increased wear rates. Switching to the higher viscosity oil keeps the engine more to the right on the curve, and I'd imagine the 10w-40 mobile 1 would be even more to the right. The only down side being higher friction, but due to fluid friction, not metal-to-metal contact. But the increased friction is worth the safety net, and it doesn't harm the engine - maybe just gas mileage slightly.
Am I on the right track here? I've switched to T6 already and am planning on trying out the M1 10W-40 suggestion next time. I also, for my own sake, want to understand why these suggestions were given. I think I kind of get why T6 was suggested but am less clear on M1, since its a 10W grade. I appreciate the help so far!
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Also, I've watched EricTheCarGuy and Scotty Kilmer on youtube talk about how switching to synthetics can cause increased oil consumption because it actually clears out sludge. I'm not sure how much truth there is to that, but it's something that previously stopped be from switching over. I'd love to hear if anyone has thoughts on that as well. Thanks!
Originally Posted By: zrxkawboy
Are the make-up quantities for real?
Are the make-up quantities for real?
Originally Posted By: awns729
The author goes on to show an example of a thinner oil vs. a thicker oil at a given RPM. The thicker oil flows less at a given pressure than the thinner oil causing the overall flow rate to be reduced. I think this is because, in his example, the thicker oil's pressure causes the relief valve to open sooner. Since the thicker oil produced more pressure at the same flow rate as the thinner oil, the thicker oil will result in the relief valve opening sooner at a lower flow rate than the thinner oil.
But I'm beginning to believe that this really isn't the full picture. Seems like T6/M1 (or any similar synthetic) would have the following benefits over the conventional that I was running:
Better flow characteristics at startup, actually resulting in less startup wear.
It was mentioned that my 5w-30 was a relatively lower viscosity at operating temperature (9.6cSt most recently and the first few samples were < 9cSt!). Someone mentioned this was close to a 20 grade oil. I'd imagine that since the viscosity is a bit low, bringing it closer to (or in) the mixed-film lubrication section of the Stribeck curve, this is potentially a reason for my increased wear rates. Switching to the higher viscosity oil keeps the engine more to the right on the curve, and I'd imagine the 10w-40 mobile 1 would be even more to the right. The only down side being higher friction, but due to fluid friction, not metal-to-metal contact. But the increased friction is worth the safety net, and it doesn't harm the engine - maybe just gas mileage slightly.
Am I on the right track here? I've switched to T6 already and am planning on trying out the M1 10W-40 suggestion next time. I also, for my own sake, want to understand why these suggestions were given. I think I kind of get why T6 was suggested but am less clear on M1, since its a 10W grade. I appreciate the help so far!
IMO, you're over thinking it. Your owner's manual allows 10W40 down to -4F. A 10W oil is tested at -25C.
http://www.pqiamerica.com/coldcrank.htm
In regards to the Motor Oil 101 article, it generalizes and doesn't take individual applications into account. And read this:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3309130/1
One reason that I recommended Mobil 1 10W40 is because it is a High Mileage oil so in theory, you should have less chance of a leaks with the switch to synthetic due to the additional seal conditioners.
If you don't have any leaks/seepage with RT6, then it should be fine. But if you're still burning oil, the 10W40 may help that because of the narrower viscosity spread.
The author goes on to show an example of a thinner oil vs. a thicker oil at a given RPM. The thicker oil flows less at a given pressure than the thinner oil causing the overall flow rate to be reduced. I think this is because, in his example, the thicker oil's pressure causes the relief valve to open sooner. Since the thicker oil produced more pressure at the same flow rate as the thinner oil, the thicker oil will result in the relief valve opening sooner at a lower flow rate than the thinner oil.
But I'm beginning to believe that this really isn't the full picture. Seems like T6/M1 (or any similar synthetic) would have the following benefits over the conventional that I was running:
Better flow characteristics at startup, actually resulting in less startup wear.
It was mentioned that my 5w-30 was a relatively lower viscosity at operating temperature (9.6cSt most recently and the first few samples were < 9cSt!). Someone mentioned this was close to a 20 grade oil. I'd imagine that since the viscosity is a bit low, bringing it closer to (or in) the mixed-film lubrication section of the Stribeck curve, this is potentially a reason for my increased wear rates. Switching to the higher viscosity oil keeps the engine more to the right on the curve, and I'd imagine the 10w-40 mobile 1 would be even more to the right. The only down side being higher friction, but due to fluid friction, not metal-to-metal contact. But the increased friction is worth the safety net, and it doesn't harm the engine - maybe just gas mileage slightly.
Am I on the right track here? I've switched to T6 already and am planning on trying out the M1 10W-40 suggestion next time. I also, for my own sake, want to understand why these suggestions were given. I think I kind of get why T6 was suggested but am less clear on M1, since its a 10W grade. I appreciate the help so far!
IMO, you're over thinking it. Your owner's manual allows 10W40 down to -4F. A 10W oil is tested at -25C.
http://www.pqiamerica.com/coldcrank.htm
In regards to the Motor Oil 101 article, it generalizes and doesn't take individual applications into account. And read this:
http://www.bobistheoilguy.com/forums/ubbthreads.php/topics/3309130/1
One reason that I recommended Mobil 1 10W40 is because it is a High Mileage oil so in theory, you should have less chance of a leaks with the switch to synthetic due to the additional seal conditioners.
If you don't have any leaks/seepage with RT6, then it should be fine. But if you're still burning oil, the 10W40 may help that because of the narrower viscosity spread.
Last edited:
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