M1 0w40 . . . . or . . . . . GC 0w30

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Originally Posted By: felixthecat

Some lingering questions :
(1) US engines need 5W-40, same engine in EU runs on 5w-30 (the only viscosity approved for VW 504/506), yet the owner's manual specifically states that only 5w-40 may be used. (Use only 0W-x or xW-30 for top ups IIRC)

The only thing I can think of is that the engines for the US market are tuned differently. They run richer due to different emission standards required here. This in turn results in higher fuel dilution. An oil with a higher starting viscosity is more likely to better cope with higher fuel dilution. It will eventually thin out to a 30-weight. If you start with a 30-weight, fuel dilution is going to push it into a 20-weight possibly which may not offer enough protection.
 
There are many 5w30s and some 0w30s on the 502/505 list (they're heavy ones) so clearly it's fine. The HTHS must be 3.5+, which is far more important than the KV.
 
I have emailed VWoA to ask just this question: is GC 0W-30 warranty certified as it is a 502 oil or do they insist on 5W-40.

I'll post if/when I get a response. As well, I will keep a printed copy in the car to take to my dealer for my next oil change.
 
Originally Posted By: dparm
There are many 5w30s and some 0w30s on the 502/505 list (they're heavy ones) so clearly it's fine. The HTHS must be 3.5+, which is far more important than the KV.


...then why wouldn't the owner's manual state "use a VW 502 oil" and leave it at that? Instaead they emphasize that the viscosity must be 5w-40 and that other viscosities are allowed but only if 5w-40 is not available.
 
I'd say because the 5w-40 is the one you should use. But the others are acceptable if it's all you can get.

Just my interpetation.
 
Originally Posted By: felixthecat

Originally Posted By: dparm
There are many 5w30s and some 0w30s on the 502/505 list (they're heavy ones) so clearly it's fine. The HTHS must be 3.5+, which is far more important than the KV.


...then why wouldn't the owner's manual state "use a VW 502 oil" and leave it at that? Instaead they emphasize that the viscosity must be 5w-40 and that other viscosities are allowed but only if 5w-40 is not available.


Enough with this [censored]. The owners manual does NOT emphasize the use of 5w40! The only thing my manual says is that the car is filled with a "high quality 5w40 synthetic" from the factory.

As for what oil to use in the 2.5L: ALL IT SAYS is to use either VW 502 or 504.

There is only so many times we can go over the same thing.

YOU CAN USE ANY OIL, ANY WEIGHT, AS LONG AS IT MEETS WHATEVER VW SPEC YOUR VW CALLS FOR.

If an oil has a VW 502spec, it can be used. End of story.
 
Well, maybe things have changed!!
Last time I read an Audi new car owner's manual ( 8 months ago) it was very precise in its language.
Perhaps you could kindly scan a page of your owner's manual that states that other viscosities and 504 oils can be used....that would be very informative.
Is your car US made? I ask because Audi's factory fill is 5W-30 even for US bound cars.
 
Originally Posted By: felixthecat
Well, maybe things have changed!!
Last time I read an Audi new car owner's manual ( 8 months ago) it was very precise in its language.
Perhaps you could kindly scan a page of your owner's manual that states that other viscosities and 504 oils can be used....that would be very informative.
Is your car US made? I ask because Audi's factory fill is 5W-30 even for US bound cars.


Here you are:
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2195047#Post2195047


The new Jetta's are not US made. They are however built in North America. Mexico to be exact.
 
Late answer but I'd go with the M1 0w-40.

It's SM rated so in theory you should have less Phosphorus in the oil, which if my memory is correct is a cat killer.

GC is only rated SL and is allowed a higher Phosphorus content.
 
The phosphorus limits for API SM are higher for xw-40 oils than they are for xw-30 oils.
 
Originally Posted By: d00df00d
The phosphorus limits for API SM are higher for xw-40 oils than they are for xw-30 oils.


I stand corrected wrt the Phosphorus!
 
Originally Posted By: d00df00d
The phosphorus limits for API SM are higher for xw-40 oils than they are for xw-30 oils.


I think in both cases the Euro specs are what limit ZDDP more, not API.

These are Euro oils that happen to meet API specs.
 
My 2004 A4 manual states that factory fill is 0W-30 and that 5W-30 and 5W-40 are acceptable if the 0W-30 is not available. Specs to meet are ACEA A2 or A3, API SJ.

That has since been superseded by TSBs and a class action for the 1.8T, and a VW 502.00 approval is required on top of the above.

I've used M1 TDT 5W-40, M1 0W-40, and (currently) GC 0W-30. [censored] if I can tell any substantive difference.

dparm, I thought the 2005 S4 manual of yours that you scanned into the other thread said 0W-30?
 
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This is what my 2005 S4 manual says:

IMG_3398.jpg
 
Originally Posted By: fredf
And still no mention of being able to use 0W-30!

It's bolded and then elaborated at the bottom.
 
Originally Posted By: d00df00d
Originally Posted By: fredf
And still no mention of being able to use 0W-30!

It's bolded and then elaborated at the bottom.


Sorry, missed that.
 
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