Oil-again

[Bob Harvey]

Since the subject has been explored extensively lately, thot I'd throw in another aspect. My Mazda PU is running synthetic in all possible applications. Like it. Just got another unit from my oldest friend (now deceased) and it too has always run synthetic. The question is ; is there any problem mixing brands (engine only) if it needs a 'top up' ? Tnx

 

[TheOldHokie]

(quoted from post at 20:07:59 01/06/14) Since the subject has been explored extensively lately, thot I'd throw in another aspect. My Mazda PU is running synthetic in all possible applications. Like it. Just got another unit from my oldest friend (now deceased) and it too has always run synthetic. The question is ; is there any problem mixing brands (engine only) if it needs a 'top up' ? Tnx

No.

TOH

 

[Fuddy Duddy]

I had always heard Castrol wasn't a good oil. Everyone that I knew that had rebuilt an engine using Castrol claimed it was always gunked up. I later heard Castrol is a good oil. The problem is that it doesn't mix well with other oils. So people would fill the engine with Castrol then latter as the oil was low put in some other oil. That's what causes it to gunk up. O'course I'm not talking synthetic here. This is just what I've heard of the Castrol brand over the years.

 

[arnold z]

I've run Castrol GTX in everything I've owned in the last 30 years, without a single oil related problem. Lack of changes and poor ventilation is more likely to sludge one up than any brand of oil.

 

[Bob Harvey]

Tnx

 

[Jimmyjack]

Mobil technical people told me it doesnt hurt to mix synthetic and regular oil either. they call it a blend, and say the synthetic oil will reach parts of the engine first in this type of weather. Ive added one quart to a change for ten years with great results. At work we had huge gear boxes that would only be under warranty if we used Mobil oil. thats when I switched. I once had an upper engine failure years ago and the mechanic that pulled it apart told me what kind of oil I had been using.(Quaker State) He claimed it had too much parifin in it for my climate?

 

[JMOR]

(quoted from post at 00:18:14 01/07/14) Mobil technical people told me it doesnt hurt to mix synthetic and regular oil either. they call it a blend, and say the synthetic oil will reach parts of the engine first in this type of weather. Ive added one quart to a change for ten years with great results. At work we had huge gear boxes that would only be under warranty if we used Mobil oil. thats when I switched. I once had an upper engine failure years ago and the mechanic that pulled it apart told me what kind of oil I had been using.(Quaker State) He claimed it had too much parifin in it for my climate?

try not to pass on old wives tales.
Quaker State was supposedly once made from Penn crude (paraffin) instead of some of the asphalt/tar? based crude from places like TX. Well, at this day in time, with world trade being what it is & pipelines all over the world, I say that virtually any oil you buy comes from an indeterminate mix or raw materials & can be blended to any specification.
......you decide.

 

[Maxwell 99]

If it were my (new to me truck) and it was running
good on a certain oil, then I would keep using
whatever oil the previous owner used. Just buy a
few extra quarts of that oil and keep them in the
toolbox to top off with.

Why borrow trouble, it should not make any
difference, but if the motor developed some type
problem, you would never know if the oil changed
caused it.

Note to file: there is a big difference in some
oils, it's the add package where the difference is
located. Oil companies add all kind of stuff to the
base oil : cleaners, chemicals, etc.

 

[Jason S.]

Penzoil,Quaker State, and Shell are all bottled by Sopus. Not much difference between those brands. As far as Castroil, when you find a Castroil refinery I will start using it. They dont have a refinery so who is bottling it? what additives does it have in it? I can tell you that Castroil synthetic is not a true synthetic. It's base stock is crude oil with synthetic additives added to it. Whereas Mobil synthetic is 100% synthetic from the base stock to the additives. Me personally I prefer Valvoline. It's refined in Kentuckey. I also like Mobil oil and Kendall, but I'll never pour Castroil in anything of mine.

 

[arnold z]

Castrol is refined by BP in Great Britain.

 

[TheOldHokie]

(quoted from post at 10:01:30 01/07/14) Penzoil,Quaker State, and Shell are all bottled by Sopus. Not much difference between those brands. As far as Castroil, when you find a Castroil refinery I will start using it. They dont have a refinery so who is bottling it? what additives does it have in it? I can tell you that Castroil synthetic is not a true synthetic. It's base stock is crude oil with synthetic additives added to it. Whereas Mobil . Me personally I prefer Valvoline. It's refined in Kentuckey. I also like Mobil oil and Kendall, but I'll never pour Castroil in anything of mine.

You are clearly a Mobil fan and a Castrol hater. How much of that is based on opinion and how much verifiable fact?

It would also be helpful if you would define what you think a true synthetic oil is. Based on your characterization of Castrol as "crude oil" and their legal history with Mobil on the designation of severely hydrocracked (Group III+) oils as synthetic I'm guessing for you synthetic is strictly a PAO (Group IV) or ester (Group V) base oil?

I'd also be real interested in hearing what you have in the way of [u:143f075b0d]hard evidence[/u:143f075b0d] to support the claim that Mobil (1 presumably) is "[i:143f075b0d] 100% synthetic from the base stock to the additives[/i:143f075b0d]". I've followed the Mobil 1 base oil debate on BITOG for several years now. I think it is safe to say that nobody outside of Mobil knows what the current blend is and when specifically pressed on the use of Group III base oils in their Mobil 1 products they won't say EITHER WAY. If they were indeed 100% PAO based you would think they would be all to happy to publicly say so. The M1 formulations have clearly varied over time, from grade to grade, and by market. It seems pretty likely that the current US market blend of 10W30 contains some amount of Group III+ base stocks. If for no other reason than they are used in some small percentage as carrier oils for the additive packages.

With the current state of refining technology the difference in performance of Group III+ base oils and Group IV or V base oils is so minimal as to be of zero practical interest to a guy maintaining his car or truck. If you are going to opt for "very high VI" grades like 0W40 you are going to get an oil that is at least partially comprised of Group IV or V base oil regardless of brand. It's about the only way you can make it.

TOH