Interesting read in Nissan GTR 2015 manual

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Hello,
I came across (in one of the recent BITOG topics) the owner's manual of the Nissan GTR 2015.

Shown in the pic below:

anonymous image hosting

Any ideas about why they believe lower than H mark oil level is more suitable for higher performance? Higher temp oil expansion?
 
My guess would be expansion. But unlike Trans fluid, motor oil doesn’t expand that much. So unless you’re going all out for extended periods of time, I can’t imagine there’d be much expansion.
 
Cooling system comment is regarding air pockets. Need to vacuum fill the system to prevent this issue.
 
I'm surprised by the first bullet in the NOTICE box about the plasma sprayed bores were developed around Mobil 1 oil, and proper operation and durability can't be ensured if other brands of 0W-40 full synthetic oils are used. :oops:
 
I'm surprised by the first bullet in the NOTICE box about the plasma sprayed bores were developed around Mobil 1 oil, and proper operation and durability can't be ensured if other brands of 0W-40 full synthetic oils are used. :oops:
Yeah I saw that too. However, if M1 reformulated their 0w-40 after this then technically the “new” M1 would potentially no longer be sufficient.

Sounds more like marketing rather than an actual concern to me.
 
I'm surprised by the first bullet in the NOTICE box about the plasma sprayed bores were developed around Mobil 1 oil, and proper operation and durability can't be ensured if other brands of 0W-40 full synthetic oils are used. :oops:
Nissan licensed that PWTA liner tech used in the GTR from Ford.
Interestingly enough, Ford doesn’t call for Mobil 1 0W-40 in any of their PWTA applications.
 
We have cars all over the place running on everything. If someone plopped down well over $100k on a car, this car can only run properly on one specific type and weight? C'mon.
 
Yeah I saw that too. However, if M1 reformulated their 0w-40 after this then technically the “new” M1 would potentially no longer be sufficient.

Sounds more like marketing rather than an actual concern to me.
Yep absolutely. Oil formulas change like the weather.
 
This has to do with the crank journals/wheights splashing in the oil and thus causing drag. This is being splashed around mostly to one side due to the rotation and causes extra oil burn on that cylinder bank. Hence why the sparkplugs on one bank are sometimes darker.

Also the reason why some cars always verry quickly consume the first 1/4th amount of oil on the dipstick and after that is goes slower.

With most race engines they also want to prevent the crank from splashing in the oil. This is elminiated with dry sump.

It could also slightly have to do with fuel dillution, however a modern emmisions approved supercar should not have such a high percentage fuel dilliution becuase running that rich would probably kill the catalyc converters.
 
This has to do with the crank journals/wheights splashing in the oil and thus causing drag. This is being splashed around mostly to one side due to the rotation and causes extra oil burn on that cylinder bank. Hence why the sparkplugs on one bank are sometimes darker.


I’d like to see some others opine on this.
 
I found this on a nissan forum:

Thanks Nick. Guess will just leave it at that level then, and check it regularly until I have a better idea how much oil my car is consuming. I thought more oil (up to the max mark) would prevent oil starvation. But in this case, it seems to cause cavitation, which reduces engine power, and turns oil into froth (adding air bubbles). So better leave it at 3/8" below max; doesn't seem to be a downside to it . Nissan should have changed the dipstick on DBA cars to reflect the top mark 3/8" below where it is now. Due to the new sump design, maybe DBA cars hold the same 5 quarts 3/8" below max, than CBAs at the max mark, no? Have a great weekend everybody

1611559887920.png

When the engine has oil all the way to max combined with high speed corners the oil seeps up to one side entering the cylinders and being splashed around by the cranckshaft causes the oil to foam. Especially to the side in which the rotation of the cranckshaft turns it pumps it into the cylinders/keeps it away from the pump.


This is a 60 degree v6, however for the 90 degree v8 which suffer this even more Bmw had a complex system on the old v8 m5s where they had secondary electric controlled oil pumps located in the cylinderheads which where controlled by the ecu, when the car noticed long hihg speed turns these pumps scavenged the oil out of the cylinderbank on that side because the oil likes to flow up through the drain canals of the cylinderhead.

Dont forget that at operating temps oil is thin like water so it will splash and creep all over the place hence why a dry sump is preffered to reduce foaming, however the vq38dett that the gtr uses doesnt have a dry sump so extra measures need to be taken.
 
I found this on a nissan forum:

Thanks Nick. Guess will just leave it at that level then, and check it regularly until I have a better idea how much oil my car is consuming. I thought more oil (up to the max mark) would prevent oil starvation. But in this case, it seems to cause cavitation, which reduces engine power, and turns oil into froth (adding air bubbles). So better leave it at 3/8" below max; doesn't seem to be a downside to it . Nissan should have changed the dipstick on DBA cars to reflect the top mark 3/8" below where it is now. Due to the new sump design, maybe DBA cars hold the same 5 quarts 3/8" below max, than CBAs at the max mark, no? Have a great weekend everybody

View attachment 42410
When the engine has oil all the way to max combined with high speed corners the oil seeps up to one side entering the cylinders and being splashed around by the cranckshaft causes the oil to foam. Especially to the side in which the rotation of the cranckshaft turns it pumps it into the cylinders/keeps it away from the pump.


This is a 60 degree v6, however for the 90 degree v8 which suffer this even more Bmw had a complex system on the old v8 m5s where they had secondary electric controlled oil pumps located in the cylinderheads which where controlled by the ecu, when the car noticed long hihg speed turns these pumps scavenged the oil out of the cylinderbank on that side because the oil likes to flow up through the drain canals of the cylinderhead.

Dont forget that at operating temps oil is thin like water so it will splash and creep all over the place hence why a dry sump is preffered to reduce foaming, however the vq38dett that the gtr uses doesnt have a dry sump so extra measures need to be taken.

Is the 1/2 a quart or so really enough to make that much of a difference?
 
Saw a Youtube video where they had an engine on the dyno...and it did produce a little more power at a lower oil level. About 5 hp IIRC.

I think it was from the "Engine Masters" tv show
 
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