Is it okay to use 5w40 instead of 5w30?

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Being boosted changes the whole situation. With the added power of the supercharger (more heat) i would recommend you trying a 5w-40.

Your engine could also be wearing out a little, with the added stress of Boost in an engine designed to be N/A, hence burning a bit more oil. I say its perfectly normal.

Check your oil level frequently.
 
Originally Posted By: Artem
Being boosted changes the whole situation. With the added power of the supercharger (more heat) i would recommend you trying a 5w-40.

Your engine could also be wearing out a little, with the added stress of Boost in an engine designed to be N/A, hence burning a bit more oil. I say its perfectly normal.

Check your oil level frequently.


I've been supercharged for a long time and have always used 5w30 without too much oil consumption but as of lately my cars been using nearly 2 qts. for 5000 oci.

I'm so confused now, sorry I didn't mention the supercharger on my original post. Does this change the whole situation like Artem says? Should I try a 5w40?

I was thinking of using 5w30 high mileage first and if the oil consumption persists, try 10w30 high mileage oil.
 
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Forced Induction means increased pressures on the internals and the bottom end so you need a thicker oil film to prevent that metal on metal contact..

Id say 5W-40 for winter... and a mix of 5W40 and 15W40 in the summer or just get the 10W-40 for summer time..
 
Originally Posted By: Audi Junkie
Plenty of turbos run on 5w-30....actually all the ones I can think of.



Does mean a thing. Those are cars designed to handle boost from the factory. The Camry engine in the TC is N/A.

Adding boost to any engine without properly building the block will result in accelerated wear (its common sense) this is the problem the OP is facing @ 130k.
 
Excellent UOA BTW!
If that's not proof you don't need go to a 40wt oil I don't know what is.
2,500 miles per qt of spirted driving is pretty good in my book.
I'd stick with Castrol Edge 5W-30 and enjoy your ride.
 
Originally Posted By: mrKiKaZ
Hey guys,

Thanks for all the informative information. Here's a little more info about my car.
It is supercharged and has 130k, mainly from lots of freeway driving daily with occasional spirited drives in the canyons and track days . I replaced the pcv valve like someone suggested yesterday, but the old one still seems good (never ever replaced).
Up to 115k miles my car would use no more then 1qt for 5000 mile oci.
Since 115k I've started to use just below 2qts for 5000 mile oci.

My owners manual says max oil consumption can be up to 1.1qt for every 600 miles. That seems really excessive! My cars never had to use near that much.

So far it sounds like 5w40 would be fine to run in my car but not the best choice. I suppose I should stay in the xW-30 oils, definitely going to try out high mileage.
While I'm not a fan of Mobil 1, they seem to be the only brand that offers a high mileage in full synthetic as I would like to stay with full synthetic oil even though I've read great things about valvoline maxlife. Seeing that I live in Socal, I'm probably going to try 10w30 high mileage.

Regarding use of rotella 5w40, I've emailed shell and was informed not to use it because my car still has catalytic converters in exhaust system.

I also had a UOA done fairly recently when I was using Castro edge, now I'm using Pennzoil ultra, still the same oil consumption with both BTW.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1902754


Very useful info.
 
Depends on what is causing the consumption. Shell did a study and found that 5W20 reduced consumption better than a 5W40 "if" it is the rings that is causing the problem. It goes against conventional wisdom but the proof lies in their study. If valve guides or seals are at fault a "thicker" oil would help. Experiment with both a 5W20 and 5W40 and see.

As a side note I would do an engine clean up with MMO as already mentioned, and go from there. JMO
 
Originally Posted By: demarpaint
Depends on what is causing the consumption. Shell did a study and found that 5W20 reduced consumption better than a 5W40 "if" it is the rings that is causing the problem. It goes against conventional wisdom but the proof lies in their study. If valve guides or seals are at fault a "thicker" oil would help. Experiment with both a 5W20 and 5W40 and see.

As a side note I would do an engine clean up with MMO as already mentioned, and go from there. JMO


Excellent point.
 
Originally Posted By: cryption
I wouldn't run 5w20 in that boosted motor.

Did you check out the superb UOA with Castrol Edge?
With a KV100 of 8.23cSt I believe he is already running a 5W-20 oil
and with excellent results.
 
I'd agree that having added boost to an engine that didn't originally have any, stepping up a grade (such as 5W-30 to 5W-40) isn't a bad idea.
 
Originally Posted By: demarpaint
Depends on what is causing the consumption. Shell did a study and found that 5W20 reduced consumption better than a 5W40 "if" it is the rings that is causing the problem. It goes against conventional wisdom but the proof lies in their study. If valve guides or seals are at fault a "thicker" oil would help. Experiment with both a 5W20 and 5W40 and see.

As a side note I would do an engine clean up with MMO as already mentioned, and go from there. JMO


Wasn't it a 5w-30?

IIRC, the reason given for that result was that they were comparing "conventional" oils, which would have given the 5w-20 an advantage: while a 5w-30 can be all-conventional, an xw-20 needs to be at least partly synthetic, even if it's not labeled as such. So, the 5w-20 actually might have been thicker than the 5w-30 in the extremely high temperature/high shear area of the piston ring, since better base stocks tend to hold up better under those conditions.

If that really is what happened, then the moral of the story is that viscosity alone doesn't tell you much about how an oil will hold up in your engine.
 
Originally Posted By: mrKiKaZ
I've been supercharged for a long time and have always used 5w30 without too much oil consumption but as of lately my cars been using nearly 2 qts. for 5000 oci.

Check your PCV system -- not just the valve -- for clogs. Look for vacuum leaks. Make sure your tune is good and you're not running rich; excess fuel can leak into the oil and volatize it. Your air filter contributes to this. O2 sensors and MAFs (if you have one) age slowly and can cause rich running that builds so slowly that you don't even notice it. Injectors might be leaking ever so slightly. If you have a tunable ECU, you can compensate.


Originally Posted By: mrKiKaZ
I'm so confused now, sorry I didn't mention the supercharger on my original post. Does this change the whole situation like Artem says? Should I try a 5w40?

Maybe, if:

A. Your oil temperature is a lot higher than normal.
B. Your oil pressure is lower than normal.
C. You have high levels of fuel dilution that you cannot prevent.

Another possibility is a valve stem or valvecover leak. These should be diagnosed and fixed; don't switch to a thicker oil to band-aid it.

The last possibility I can think of is that your piston rings or cylinder walls may be wearing out. Thicker oil can help with this, but it's usually better to go with a better oil rather than a thicker one if you can.


Originally Posted By: mrKiKaZ
I was thinking of using 5w30 high mileage first and if the oil consumption persists, try 10w30 high mileage oil.

Not a bad plan. But definitely check the hardware as well. If there is a fixable problem, you'll want to fix it.
 
Originally Posted By: jorton
Originally Posted By: mrKiKaZ
Hey guys,

Thanks for all the informative information. Here's a little more info about my car.
It is supercharged and has 130k, mainly from lots of freeway driving daily with occasional spirited drives in the canyons and track days . I replaced the pcv valve like someone suggested yesterday, but the old one still seems good (never ever replaced).
Up to 115k miles my car would use no more then 1qt for 5000 mile oci.
Since 115k I've started to use just below 2qts for 5000 mile oci.

My owners manual says max oil consumption can be up to 1.1qt for every 600 miles. That seems really excessive! My cars never had to use near that much.

So far it sounds like 5w40 would be fine to run in my car but not the best choice. I suppose I should stay in the xW-30 oils, definitely going to try out high mileage.
While I'm not a fan of Mobil 1, they seem to be the only brand that offers a high mileage in full synthetic as I would like to stay with full synthetic oil even though I've read great things about valvoline maxlife. Seeing that I live in Socal, I'm probably going to try 10w30 high mileage.

Regarding use of rotella 5w40, I've emailed shell and was informed not to use it because my car still has catalytic converters in exhaust system.

I also had a UOA done fairly recently when I was using Castro edge, now I'm using Pennzoil ultra, still the same oil consumption with both BTW.

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1902754


Very useful info.


Rotella 5w40 is SM rated no worries about your cats, shell is doing a cya.
 
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