Castrol vs Royal Purple?

[FriboRage]

2004 Pontiac Grand Prix GTP (3.8L Supercharged), 120k miles, live in the Northeast US. Daily driver in the summer, spends a lot of time sleeping in the winter... though I drive it if the roads are dry in the winter.

I've been using Castrol Edge 0w30 Euro Formula for awhile now and I like it. The engine sounded a lot quieter than the Mobil 1 0w30. Ran good, planned on keeping it, but Advance stopped carrying it so I have no clue where to get it now.

They have Royal Purple on sale at the moment, but no 0w30, so Im wondering how the RP 5w30 stacks up against the Edge 0w30 Euro.

Opinions, suggestions?

 

[Garak]

I'm sure it would be fine, but if you're wishing to find something similar to the Castrol 0w30 A3/B4, you should compare similar products, such as RP 0w-40 or 5w-40, or Mobil 1 0w-40, other Castrol A3/B4 varieties, and whatever Shell might have available in A3/B4.

RP 5w30 is simply an ILSAC 5w30, much akin to Castrol 5w30 or Mobil 1 5w30 or any of the similar suspects.

 

[Delta]

Castrol Edge 0w40 is dang close to the Edge 0w30 in thickness. I don't know the specific numbers, but I know someone will chime in.

 

[jdavis]

Mobil 1 Full Synthetic 0w40 might be a good switch, should be easily available at Walmart and appears to be a great oil.

By the way, Autozone should have Castrol 0w30 if you really wanted to stick with it.

 

[Olas]

eBay and Amazon both have Castrol 0w30

 

[beanoil]

AZ, Castrol 0w30. Good grief, please do not drink the RP Koolaid.

 

[901Memphis]

The API version of royal purple is nothing special if you ask me but the stuff with synerlec is worth getting. Mobil 1 0W40 isn't much thicker than Castrol 0w30, but Mobil 1 0w30 is much thinner than both iirc since it's not a European grade it's just a 5w30 substitute for cold climates

 

[69GTX]

Originally Posted By: jdavis
Mobil 1 FS 0w-40 might be a good switch, should be easily available at Walmart and appears to be a great oil.

By the way, Autozone should have Castrol 0w30 if you really wanted to stick with it.



The Mobil 1 0w-40 viscosity had dropped considerably to 12.9 cSt. Mobil 1 offering $12 rebates per 5 qts through May 31st. You can buy it for a net of $2.69/qt before taxes.

Pennzoil Ultra 0w-40 SRT is about the same viscosity as the Mobil 1. Both are very light 40 grades. The SRT becomes a 30 grade within 500-1000 miles. A lot of people stocked up on it for $2/qt back in December. Pennzoil as well is offering rebates for the rest of 2016. RP wouldn't even be on my radar unless I could buy if for $4/qt or less.

 

[aquariuscsm]

Originally Posted By: Delta
Castrol Edge 0w40 is dang close to the Edge 0w30 in thickness. I don't know the specific numbers, but I know someone will chime in.


This. And it's cheap at Walmart.

 

[GMBoy]

That engine prefers and is spec'd for 10w30. I use Mobil 1 Extended Performance 10w30 in my 3.8 supercharged Regal GS.

 

[FriboRage]

Thanks for the feedback everyone. I think I'm going to try switching to the Castrol EDGE 0w40 and see how it goes. I think I'm going to try out the purolator boss filter, too.

 

[Olas]

Originally Posted By: 901Memphis
but Mobil 1 0w30 is much thinner than both iirc since it's not a European grade it's just a 5w30 substitute for cold climates


There's some confusion here, in Europe we use viscosity grades as defined by SAE J300 as does the rest of the world.
Talk of a "European grade" is nonsense tbh

 

[Garak]

Well, it's partially nonsense, but cannot be discounted. A 0w30 is a 0w-30, after all, and meets the cold cranking and MRV requirements for the 0w- part and the KV100 range for the 30 part. But, HTHS can be significantly different. You'll find an ILSAC 0w30 having an HTHS of maybe 3.0, whereas a 0w30 A3/B4 will have an HTHS of 3.5 or higher, and that does make a difference.

I would not be using Mobil 1 Advanced Fuel Economy 0w30 or Petro-Canada 0w30 in a BMW LL-01 application without some very careful consideration, but Castrol 0w30 A3/B4 will be perfectly acceptable. The issue with the OP's question is that GC 0w30 is not very comparable to Mobil 1 Advanced Fuel Economy or RP's API 5w30.

You should see some of the troubles that some North American VW/Audi dealers had some years back when they thought Castrol 0w30 ILSAC was a valid replacement for Castrol 0w30 A3/B4, or that GTX 5w30 ILSAC was a replacement for the OE Professional 5w30 A3/B4. It didn't go well for them.

 

[zeng]

Originally Posted By: Garak
But, HTHS can be significantly different. You'll find an ILSAC 0w30 having an HTHS of maybe 3.0, whereas a 0w30 A3/B4 will have an HTHS of 3.5 or higher, and that does make a difference.



+1

HTHS IS significantly different!