# oil wheigth 5w-30 vs 5w-40



## efsiller (Apr 13, 2009)

Just took car to dealer for the 10k service, they used 5w-30 instead of the "reccommended" 5w-40. 
Does it make a difference? Should I have them changed it for 5w-40?
Thanks


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## VTM2007 (Apr 23, 2008)

*Re: oil wheigth 5w-30 vs 5w-40 (efsiller)*

I use the 5w-30 when i change my oil. Because the owners manual i think says its fine if you cant find 5w-40. I can not find 5w-40 around my house except online and its like 9 bucks a qt.


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## SpiderX1016 (Jul 22, 2008)

You're going to be fine. I use 5w-30 Pentosin or w.e (a mechanic put in some oil made in Germany, So I'm just guessing). Been thinking about using Shell oil 5w-40 but I don't care.


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## efsiller (Apr 13, 2009)

Thanks for your responses, one more question do you guys let the oil go for the 10K intervals the manual says?


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## mattkosem (Apr 29, 2004)

If it's a high quality synthetic that has the proper VW spec (502.00 IIRC), it should be fine. If you want to be certain, you can send it out for analysis once you have changed it.
--Matt


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## spitpilot (Feb 14, 2000)

*Re: (mattkosem)*

It's getting to be summer time...and if you drive at high speeds for long periods of time...the extra viscosity @ temp (the second # in the oil weight code) will give you added engine protection...I'd use 30w oil in fall and winter, but try to stick with 40w for late spring/summer use! http://****************.com/smile/emthup.gif Our Walmart carries 0-40w Mobil 1 for about $6/quart...


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## SpiderX1016 (Jul 22, 2008)

*Re: oil wheigth 5w-30 vs 5w-40 (efsiller)*


_Quote, originally posted by *efsiller* »_Thanks for your responses, one more question do you guys let the oil go for the 10K intervals the manual says?

I do more like 6k-7.5k.
I don't feel comfortable doing 10k but you should be fine with it.


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## BuddyWh (Nov 11, 2006)

*Re: oil wheigth 5w-30 vs 5w-40 (efsiller)*

Just to add to the discussion a little: as you should expect the specification for oil weights is actually a range of viscosities, not a single point value. Many oils are manufactured to the high side of the range, and others to the low side. 
I wonder if a 5w30 oil that is VW502 certified is to the high(er) side of the range. Point being is that VW502 spec probably doesn't specifically care about the weight 'rating', but the actual viscosity of the oil.



_Modified by BuddyWh at 8:13 AM 6-22-2009_


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## efsiller (Apr 13, 2009)

*Re: oil wheigth 5w-30 vs 5w-40 (efsiller)*

So what do you think will be better, the 5W-30 oil from the dealer or Mobil 0W-40 or Castrol 5W-40.
And about going 10K between oil changes, what about changing the filter at 5K and refill what ever is needed.
Also, I am getting about 3 less MPG since that oil change (5W-30) coould it be just the oil being new or being 5W-30


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## BuddyWh (Nov 11, 2006)

*Re: oil wheigth 5w-30 vs 5w-40 (efsiller)*


_Quote, originally posted by *efsiller* »_So what do you think will be better, the 5W-30 oil from the dealer or Mobil 0W-40 or Castrol 5W-40.
And about going 10K between oil changes, what about changing the filter at 5K and refill what ever is needed.
Also, I am getting about 3 less MPG since that oil change (5W-30) coould it be just the oil being new or being 5W-30

Assume the dealer used a VW502 oil, it largely comes to personal choice. Personally, I like Mobil1, but my dealer uses Castrol I think. I'm not worried.
3 MPG delta is noise....can't draw any conclusions from such a tiny difference. 
If you wanna get into the 10k vs 5k arguments, just look back in the forums where it's already beat to death. For me, the facts that VW502 oils are fabulous, this engine is designed for long service intervals (large oil gty and large capacity filter) 10k seems really conservative. People's oil change analysis results have supported that. I'm comfortable with it so long as I drive it enough within the year.
Oh...all of this is qualified that you are driving largely unmodified engine (CAI and exhaust is OK) in largely normal driving patterns...


_Modified by BuddyWh at 10:10 AM 6-22-2009_


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