0w30 instead of 5W40 or 15W40

[kickster]

My Golf as I stated before asks for thick oil during summer months when temp is above 15C.
Currently I am using AMSOIL 5W40 but for next oil change I would like to go to GC or AMSOIL 0W30. I have heard that both of these oils are on thick side of 30 weight.

I plan on running it for a full year with an oil analysis at 5000KM mark. If the oil analysis shows normal wear, should I continue on using it? Does that mean that a thin synthetic oil is enough for my old clunker? Could the thin oil do any damage that does not show up on UOA radar? does Sludge, oxidation and oil cooking show up on UOA?

 

[TR3-2001SE]

Lots of questions to answer. First yes if the analysis shows excellent ware numbers you be fine to extend it past 5000KM which it probably will.
I think a 0-30 of the Amsoil varity would be excellent in almost any engine except maybe one with loads of oil consumption. It is really only thin at cold temp. so no damage could occure using this oil unless you are road racing. It would indeed show up in a UOA. Oxidation would show on a UOA but sludge is still a mystery to me. Maybe Terry Dyson analysis may be able to see it comming.
You are using a top of the line oil so just do your UOA's and everything will be fine.

 

[dropitby]

Well your in luck I just came home from Autozone and got their last 6 bottles of GC (yes the RED label made in Germany)for $25 and change it has never been this cheap.

 

[Dr. T]

Well, if it's the A3 rated stuff, then you should be fine other than seeing an increase in consumption (something I don't like). Also, 5k km is wasted $ interval with such oils.

 

[kickster]

I did not say I would go only 5000KM. I said I will do an UOA at 5000 Mark. If things are normal I will continue using it if not I will replace it.


PS. What is A3 rated oil?

 

[Spector]

I went from the Amsoil 10W30 to the Schaeffers 15W40 in my 167,000 mile Camry in the hope of reducing slight consumption and at least equal wear. Well, the wear stayed the same but the consumption did also. Thus, I am going to go with the Amsoil 0W30 and see what happens. I have it in one car with great results but have been reluctant to spend the extra $2/quart for it. Time to try it in the high mileage and see what happens. In the one I do use it in I go 1 year or approx 10-12,000 miles.

 

[Patman]

quote:

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Originally posted by kickster:
I did not say I would go only 5000KM. I said I will do an UOA at 5000 Mark. If things are normal I will continue using it if not I will replace it.


PS. What is A3 rated oil?

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An A3 rated oil must have an HTHS of higher than 3.5 for one.

You should have no trouble running GC 0w30 in the VW, even though it calls for 5w40. Most 5w40s out there are thin 40wts which thin out to a 30wt anyhow. While GC is a thick 30wt which often thickens up to a thin 40wt. So it's the same either way you slice it. My mom's 2001 Golf 2.0 calls for 5w40 but I'm running GC 0w30 in it. She does mostly short trips anyhow, so I could probably run 0w20 in it and it wouldn't hurt her engine, especially with her extremely light right foot. (she never goes full throttle ever and never goes above 3500rpm ever either)

 

[kickster]

Patman, my Giolf is not same as yours. I have a 1990 1.8 8v engine which calls for 15W40 or 20W50 during summer. This is why I am a little scared to use thin oil.

 

[kickster]

I got a copy of my owner's manual.
here is the actual suggested oil viscosities vs. Temp.

This is why I am a little scared to use 0w30.