Castrol, German Castrol & Blending

[Jim Allen]

I've been considering going the blending route with Castrol, e.g. 3 qts 5w30 GTX and 2 qts Syntec 5w30. My research here seems to indicate that's a good mix, kinda like Syntec Blend oughtta be.

The recent discussion on the German Castrol got me to wondering. In a blend as outlined above,...

1) Would the GIII base of the American Syntec make a better mix in the GTX GII (presumably it's a GII) than the PAO of the GC? If so, or not, why?

2) Secondarily, what effect would mixing 0W30 in with 5w30?

FInally, I heve checked several AutoZones around here (NW Ohio) and none currently have GC on their shelves. I did not interrogate the staff as to why, because I have not made up my mind, but is the GC confirmed to still be offered at AutoZone?.

Thoughts, Gents?

Jim Allen

 

[vad]

Regarding mixing. I don't mix and advise against that.
Even though you won't harm your engine in any way I would leave the art of blending to the people who know exactly what they're doing.
I can't really see any benefits or savings you can achieve by making your home brews.
In regards of GC.
The most of AutoZones are well stocked with the current (Gold) version of GC. If your local AutoZones don't have it in stock then clerks will order it for you unless for whatever reason the store doesn't carry it at all. That might be the case with the smaller stores.
GC is currently on sale, again, at $3.99 qt. That might explain why they run out of it.
Frankly I don't know why at this price levels you would want to "contaminate" the German "Elixir".
I consider GC to be the best bargain on the oil market, especially so at the current sale prices. In most cases you can run it for up to 10K, easily, or even longer...
Why to tinker with a good thing?

 

[Triple_Se7en]

The 0Ws are a different breed of oils that have special modifiers & balancers. They should not be mixed. Castrol Syntec-Blend is already a mix of Syntec & GTX. If Castrol can blend it -- then so can you.

 

[vwoom]

I agree with Blue99, I usually mix motor oils albeit aiming with the same brands..but GC 0w30 I never manipulate it's chemistry. Being the best-of-the-best for your performance oil buck, it's pretty logical to leave it's magic untampered.

 

[Blue99]

GC 0w30 has a magnesium based detergent/dispersant additive and I don't like ths idea of mixing this with a moly-boron-calcium add package.

Also, to me, the performance of the special esters in GC creates an unknown when blended with another oil. If the esters get diluted by another oil, does the 0W rating quickly become a 10W?

A Castrol GTX 5w30 & Syntec 5w30 blend makes more sense as a home brew candidate. The additive packages are similar, both are starburst energy conserving oils with VI improvers & friction modifiers.

The Grp III Syntec 5w30 mixed with Grp II+ GTX should generate a blend with good winter cold start performance.