Sorry Gord, have to go with Nubo on the mixing thing, the synth additive package could be based on different chemicals which may not 'play well with others'. One brand of detergent may precipitate out all the 'other' brands anti-wear package, for instance.

However, you are on safe ground with Castrol Syntec, because (apart from some rare imports from Castrol Germany) it is NOT a synthetic oil at all! Syntec's base stock is 'severely hydrotreated', which is basically dino oil, ultra-refined.

Mobil, Amsoil, Royal Purple etc. are not formulated with dino base stocks.

Mobil appealed to the SAE over Castrols use of the term synthetic, but was over ruled. In the industry it is referred to as 'FakeTec' It is still marketed as a premium brand and is 3 or 4 times the price of 'dino'.


A link to my favorite oil forum - 'bobistheoilguy'
Read more on FakeTec etc.
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doc

 

I did do a link in the other oil thread and posted a link where mobil says that you can mix mobil one with just about any other oil, too.

 

Doc, you're back! Thanks for the feedback.

Yeah, I normally don't like mixing oils for that reason. But I prefer synth, and still want the free oil changes... maybe I should just give up on the freebies and do it right myself! What are you planning?

Yeah, I'm familiar with Mobil's suit about Syntec's synthetic-ness. I've posted on here a few times when people are parroting the "no synthetics for rotaries" that Syntec must be OK since Mobil says it's not really synthetic. For some reason, nobody ever responds to that point... I use Mobil1 in my other vehicles, but figures I'd use Syntec for the RX-8 just to have that loophole if I ever did have a engine problem and a warranty fight.

Regards,
Gordon:p

 

Say now, which ones are those? I've seen one store in Calgary that has a Syntec 0W40 (IIRC) with a special box on the label stating that it meets some VW spec - is that the stuff? I was curious if I might want to try it in my Audi...

Regards,
Gordon

 

I've just been searching around for 5W20 distributors, and I ran across this specification comparison from AMSOIL. Thought I would post the link for people to make their own judgements about whether synthetic is OK, the argument being that it doesn't 'burn'. Anyway, I found my AMSOil dealer from years past and will be giving him a call for some XL-7500 5W20. Here's the link - the legend at the top describes the categories rated. Pay particular attention to the FP (flash point) column:

http://www.bestsyntheticoil.com/deal...ne-17-2003.pdf


Hope everyone had a nice Thanksgiving

 

Used to run an AMSOIL product that was called a para-synthetic years ago in my 79 RX-7... got gas mpg increase and was quieter.

I am interested in someone reporting their findings regards AMSOIL and the Rensis motor.

 

all i know is that my salesman told me not to use synthetic....

but what do those salesmen know

 

I do not accept statements from sales persons as expert advice. There are some very good shops like Mazda Tech that have been working on these engines for years. These folks along with inputs from racing teams and independent testors would help to bring this to closure.

As I see it, AMSOIL meets the SL API rating. Specifics on wear, residue build up and the like is needed.

 

Yes, the German import Syntec stuff IS full synthetic, and right now all the retail outlets seem to have it. It is rated 0w-30, and is clearly marked "Made in Germany' on the back label.

If you read up on the pre/post oil tests, you will appreciate its excellent anti-wear properties - it has no equal. Amsoil and M1 come a close second.

Unfortunately it is still premium price - the best I've seen is $6.40 a litre (Canuk) @ WallyMart.
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doc

 

Synth or Dino - which to use?
So much to gain So much to loose
Is one better
Or is it the other
This thread is tired
Let's start another!
"Mazda says no"
or is it...
"Mazda don't care"
The suspense is driving
Me crazy I swear
Molecules dancing around in my head
Hydrogen blue and Carbon is red
(Kekule had similar nightmares it's said)
No decision in sight; I begin to despair
Then an answer appears as if from thin air!
"They all meet SL" a little voice states
"Frequent changes to reliabilty equates"
"You could buy what's on sale"
"But you ain't got a Dodge"
"Why not get something that looks good in the garage?"
"Your new car'll be Yellow so why not decide"
"Your 'official oil' will match with your ride"?
"Yellow car on the floor"
"Yellow cans on the shelf"!
The last was the last that I heard from my elf.
"Pennzoil!" is the message the little dude sent.
As good as any I figured, my energy spent.
So there you have it Ladies and Gents
You have my decision
And my 2 cents.

 

Bravo! LOL! :D :D :D