More oil consumption with Castrol 0w40 over 0w30?

[levesqu6]

2006 bmw 330i with the NA N52 straight 6. I have previously been using longlife-01 Castrol 0w30 and switched to longlife-01 Castrol 0w40 since its cheaper, available locally, and so i can just buy one type of oil for it and the old m3. I have have noticed around another quart of oil consumption over 10k miles with the 0w40. This question is more of a curiosity if a thicker oil could burn at a higher rate than a thinner oil. In my case it is possible that theres something else like the weeping oil pan got worse (though i havent noticed spots on driveway).

 

[WhizkidTN]

I'd check your PCV valve.

 

[andrewp1998]

aks trav!

 

[The_Nuke]

Not unheard of in some engines. See if you can find the NOACK values for each on PQI. If the 0W-40 has a higher NOACK, the behavior you're seeing is normL, for lack of a better word, and shouldnt be of great concern IMHO.

 

[umungus1122]

A qt. over 10k miles is no biggie. It happens when changing grades/brands also sometimes.

 

[mightymousetech]

Just curious how you noticed the consumption? Did you get the "add a L" warning? Maybe it is just your sensor giving a strange reading, can be caused by a little water contamination in the oil.

 

[levesqu6]

The car has a electronic dip stick so thats how i know when to add. It gets driven primarily on the highway for a least 25miles at a time so I'd be surprised if there was much water in the oil.

When i say a quart more i think it went from 1.5 to 2.5quarts over 10k miles. Still plenty acceptable but I'm asking here out of curiosity. I havent had a chance to find the NOACK % for these oils. Didnt know what that was until you suggested looking into it!

 

[KL31]

Could be coincidence and could be that you'll need to do a few runs on the 0w40 to see if that level of consumption continues or not.

 

[SR5]

Quote:
330i with the NA N52 straight 6

That is a nice engine.

 

[mightymousetech]

Originally Posted By: levesqu6
The car has a electronic dip stick so thats how i know when to add. It gets driven primarily on the highway for a least 25miles at a time so I'd be surprised if there was much water in the oil.

When i say a quart more i think it went from 1.5 to 2.5quarts over 10k miles. Still plenty acceptable but I'm asking here out of curiosity. I havent had a chance to find the NOACK % for these oils. Didnt know what that was until you suggested looking into it!


Interesting. Yes, I know about the electronic dipstick, have had many BMWs, including the same 06 330 as you. I would like this is just a coincidence as the 0W30 and 0W40 are nearly the exact same oil. Only a very slight difference in 100 C viscosity between the two.

 

[levesqu6]

Originally Posted By: SR5
Quote:
330i with the NA N52 straight 6

That is a nice engine.


it is! its got a few typical bmw issues... leaky valve covers, oil pan gaskets, eats a water pump before 100k miles ($500 electric unit), ignition coils, and vanos solenoids that need to be cleaned or replaced every 100k. The engine is throttled by variable valve lift which I think is the source of the delay that makes it a challenging powertrain to drive smoothly when coupled with a manual transmission. But it makes great smooth power, and is very light since it has a magnesium alloy block.