2011 qx56 vk56vd 5.6L V8 - recommended oil

[Tommy Boy]

First off honored to have found this site. The information, knowledge and good banter is superlative. My wife thinks I’ve lost it and maybe I have haha because I scroll for hours on this site.

I don’t see a lot of data on this site about my suv or its user search error. 2nd owner got at 90k now 125k. Got it for the wife to drive family to school and around city.. trips as well. We are in Georgia.

Calls for 5w30 and unless told otherwise I’ll continue. Doing my own oil changes 3k miles vs dealership recommended 5k.

Currently using QSFS 5w30 with good results. About to hit next OC thinking PUP, PP and maybe a M EP. I’ll submit VOAs after each for review but wanted to know from the vast knowledge within this site what you would recommend for best performance and longevity of engine.

Dealer is using pennzoil gold blend which appears to have a nice VI, which was interesting.

Thank you!

 

[NormanBuntz]

I have two Infiniti models and my vote is to continue using QSFS, readily available at Walmart. I have a large stash of Rotella Gas Truck 5w-30 and 5w-20.

 

[JavierH19]

QS 5w-40 is what i'd use.

 

[Tommy Boy]

I have two Infiniti models and my vote is to continue using QSFS, readily available at Walmart. I have a large stash of Rotella Gas Truck 5w-30 and 5w-20.

Agree. Seems to be working well and meets all specs.

 

[Tommy Boy]

QS 5w-40 is what i'd use.

Good point. Had same thought but noticed the VI is lower vs qsfs and would it not unnecessary wear on any clearances from being thicker? Am I over analyzing?

 

[JavierH19]

Good point. Had same thought but noticed the VI is lower vs qsfs and would it not unnecessary wear on any clearances from being thicker? Am I over analyzing?

No concern until it gets to 20 below

 

[kschachn]

Good point. Had same thought but noticed the VI is lower vs qsfs and would it not unnecessary wear on any clearances from being thicker? Am I over analyzing?

What?

 

[Tommy Boy]

No concern until it gets to 20 below

Got it

 

[Tommy Boy]

What?

 

[Tommy Boy]

CST 100 0w40 is 13.3 which is over the max recommended 12.5 for called for 5w30. I have read on this site to stick with oem recommended oil weight. Have also read on here that the extra density of the oil can cause more pressure wear causing clearances to broaden. Lastly, thought the higher VI of an oil the more stable it is and the qsfs has a higher vi vs 0w40.

 

[proveitwithdata]

how are the cats on the vehicle?

 

[Tommy Boy]

how are the cats on the vehicle?

Replaced at 70k. All is fine.

Also since it’s direct injection do I want a full saps vs low. Isn’t 5w40 full vs 5w30?

 

[JavierH19]

Replaced at 70k. All is fine.

Also since it’s direct injection do I want a full saps vs low. Isn’t 5w40 full vs 5w30?

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a no vii oil.

 

[kschachn]

CST 100 0w40 is 13.3 which is over the max recommended 12.5 for called for 5w30. I have read on this site to stick with oem recommended oil weight. Have also read on here that the extra density of the oil can cause more pressure wear causing clearances to broaden. Lastly, thought the higher VI of an oil the more stable it is and the qsfs has a higher vi vs 0w40.

No. More wear is caused by thinner oils, not the other way around. Clearances do not "broaden" by using an oil with a somewhat higher HT/HS. That's what keeps the parts separated and reduces wear.

 

[kschachn]

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a no vii oil.

I think he's confounding VI and VII.

 

[himemsys]

CST 100 0w40 is 13.3 which is over the max recommended 12.5 for called for 5w30. I have read on this site to stick with oem recommended oil weight. Have also read on here that the extra density of the oil can cause more pressure wear causing clearances to broaden. Lastly, thought the higher VI of an oil the more stable it is and the qsfs has a higher vi vs 0w40.

@kschachn speaks truth. Clearances do not grow if you use a thicker oil.

I think before you make a decision, you should send a sample in to a lab that uses gas chromatography (such as Oil Analyzers). Get a general idea of fuel dilution in your engine before making a decision. If your engine is currently thinning 5W30 to a 20 grade, then definitely consider a 5W40. If it's not, stay at 5W30.

 

[Tommy Boy]

I l

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a no vii oil.

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a no vii

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a

No the modern SP formula is lower saps so it's not a concern. But direct injection on its own won't cause lspi. It's when you have both turbo and gdi that you'll have it as turbos exasperate it. My 2021's 6.2 is gdi and I run as 5w-40. Zero problems and I expect that. Also you say that higher vii is more stable and better but I think you have it mixed up. Having less vii or less polymers is better as it makes the oil more shear stable both mechanically from stress and heat and also chemically as gasoline attacks it. Oils with a lower vii achieve better protection at the cost of low temp pumpability but that doesn't matter if it doesn't get cold enough. It's why hpl makes a no vii oil.

Thank you for the help and details. Most excellent.

 

[Tommy Boy]

I think he's confounding VI and VII.

Agreed. No way an expert. Just trying best to learn and understand. Thank you for the help!

 

[Tommy Boy]

@kschachn speaks truth. Clearances do not grow if you use a thicker oil.

I think before you make a decision, you should send a sample in to a lab that uses gas chromatography (such as Oil Analyzers). Get a general idea of fuel dilution in your engine before making a decision. If your engine is currently thinning 5W30 to a 20 grade, then definitely consider a 5W40. If it's not, stay at 5W30.

Understand. Agreed will do some oil sample and post. Thank you for the help.

 

[Tommy Boy]

Ok first oil sample. QSFS 5-30 for 3k and reused the oem oil filter that had 3k on it. So oil filter had a total of 6k. Yes, not doing that again and will change oil filter each oil change.