Mixing Castrol Syntec and dino GTX

[Dominik]

I tried to get this question out to the group but no one seemed to notice it ..... hence:
How good or bad is it to mix GTX 5W-30 and Syntec 5W-50 ? I am aiming at increasing the viscosity for a piston slapping GM 3.1 engine. I also like the fact that GTX has some molly in it, does Syntec??.
Are thetre a lot of Castrol mixers here?
Please let me know what you think of it.

 

[sbc350gearhead]

It has been stated that the additive package is different between the GTX and the Syntec and will clash. I don't know if the U.S. made syntec has moly or not. The german stuff doesn't.

Do you have your heart set on the GTX? or are you willing to switch to another brand?

 

[Dominik]

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Do you have your heart set on the GTX? or are you willing to switch to another brand? [/QB]

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No not really just trying to thicken up the oil to reduce slapping , and I happen to have two quarts of each Syntec and GTX.
Thanks for the reply

 

[Ray H]

"Additive clash" is an overblown concept - even between dissimilar brand oils.

 

[sbc350gearhead]

quote:

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Originally posted by Ray H:
"Additive clash" is an overblown concept - even between dissimilar brand oils.

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I would imagine that the additive clash wouldn't matter too much in a 3000 mile OCI. I don't know if I would push it too far though. I needed to get rid of alot of orphaned bottles of oil not too long ago. I mixed 4 types of oil in my camry, but most of it was pennzoil and I only ran it 2000 miles.

 

[Cutehumor]

quote:

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Originally posted by sbc350gearhead:

quote:

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Originally posted by Ray H:
"Additive clash" is an overblown concept - even between dissimilar brand oils.

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I would imagine that the additive clash wouldn't matter too much in a 3000 mile OCI. I don't know if I would push it too far though. I needed to get rid of alot of orphaned bottles of oil not too long ago. I mixed 4 types of oil in my camry, but most of it was pennzoil and I only ran it 2000 miles.

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hey sbc,that would have been one interesting UOA

When I was switching from valvoline maxlife to exxon superflo, I had two bottles left of the maxlife stuff. Unfortunately, my g/f sunfire was quite an oil burner but I got to use up the rest of my maxlife in her car and even half a quart of superflo in her car. It had pennzoil high mileage oil in there too. It had three different brands of oil into my g/f car when it was low. but hey it wasn't my car.

She's lucky I checked the oil and filled it with oil. She never checks oil, I don't think she knows how. I would show her, but she doesn't care.

 

[sbc350gearhead]

quote:

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Originally posted by Cutehumor:
hey sbc,that would have been one interesting UOA

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Wouldn't it though. 2.3 quarts pennzoil dino, 1 quart pennzoil synthetic, half quart supertech synthetic, half quart havoline synthetic. I wonder if you can have 200% oxidation

 

[JonS]

This is the only time iv'e mixed oils. I used 4 qrts GTX 10w-30 with 2 qrts 10w-30 syntec in my Jeep. About 200 miles later, My valve cover gasket seemed to slip out. It leaked alot. I never had leaks before. The valve cover gasket seemed to be pushed out from the inside to the out. It looked like a hurniated (sp) gasket. The gasket was rubber. I don't know if it was excess pressure or what. Or related to the oil.