Castrol 5w40 vs Castrol 0w40

[edyvw]

Originally Posted by KCJeep
This UOA just posted shows near identical shear with 0w40 at only 1800 miles. On paper the 0w40 is better oil with some PAO and Ti, but in actual practice I don't think it makes much difference.

https://www.bobistheoilguy.com/foru...stro-edge-0w-40-2013-bmw-n52#Post5411834

This one is a bit better but still only 3500 miles.

https://www.bobistheoilguy.com/foru...m-2009-volkswagen-city-jetta#Post5404361

Such dramatic drop in N52 means one issue: coil packs! There is a proble with burn there, and those packs have to be religiously replaced.
Second UOA is EA113, notorious fuel diluter.

There has to be UOA in the same engine.

 

[SEMI_287]

Walmart.com was selling 5 quart jugs of 0w40 for $19 a piece a couple days ago. I grabbed 4 jugs myself. Earlier this month Advance had Castrol Edge oils on sale, including 0w30. For $6.66 a quart i stocked up.

 

[GJM120]

The shear in the 0W/40 is not much worse or even as bad as the 5W/40 if you take into account the spec viscosity for the 2 oils are 13.1 and 14.1, respectively?

Edge 0W/40 is a 'thin' 40 grade.

 

[edyvw]

Originally Posted by GJM120
The shear in the 0W/40 is not much worse or even as bad as the 5W/40 if you take into account the spec viscosity for the 2 oils are 13.1 and 14.1, respectively?

Edge 0W/40 is a 'thin' 40 grade.

One has to compare two oils in the same engine. But you are right, 0W40 start thinner than 5W40, while having same HTHS.

 

[Gokhan]

Originally Posted by Patman
I see a lot of people praising Castrol's 0w40 on here but I never see anyone talking about their 5w40 at all, is it really that inferior? My local Costco carries the 5L jug of 5w40 for $32 CDN, although it's still cheaper for me to buy Castrol 0w40 across the border in a US Walmart.

So what is it about the 5w40 that rubs my fellow BITOGers the wrong way?

The BITOG'ers know it! Yes, Castrol 5W-40 A3/B4 is significantly inferior to both Castrol 0W-40 A3/B4 and Mobil 1 FS 0W-40 A3/B4. I wouldn't give it any thought unless the availability or price is an issue. It's a Group-III-based oil, whereas the 0W-40's have a lot of PAO (for Castrol) and GTL, some PAO, and some POE (for Mobil 1). The two 0W-40's will have a lower Noack, a thicker base oil, and less VII than the 5W-40 thanks to the higher-VI, higher-quality base oil, and they will result in a cleaner engine and longer OCI's. Therefore, in this case the two 0W-40's are both slightly thicker than the 5W-40 in most operating conditions, such as at the higher shear rates routinely experienced in the valvetrain, timing chain, piston rings, and cylinders, thanks to the thicker base oil and lower VII content. Castrol 5W-40 A3/B4 is similar in quality to Mobil Super Euro 5W-40, the latter of which has either lower HTHS or less VII -- if I had its HTHS value, I could estimate its relative VII content.

Estimated base-oil viscosity at 150 C (BO DV150) and VII content of selected oils