# Climate effects on oil?



## epearson (Dec 4, 2005)

My car is at about 27k miles and so far I have followed the manufacturer schedule of maintenance done at 5k, 10k, and 20k. I'm taking a 2k mile road trip next week and asked the dealer if they thought I'd be safe to wait and do the 30k oil change after or do it now. 

The dealer recommended the oil change now and the rest of the maintenance afterward (which is what I was leaning toward anyway). He then emphasized that they actually recommend the oil changes every 5k miles due to our climate (Phoenix area). Does anyone know if the climate has a significant effect on the oil? Changing every 5k isn't a bad idea but so far I've chosen to trust VW and go with 10k changes assuming the dealership is more motivated by revenue than just the welfare of the engine. 

Thanks :thumbup:


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## saaber2 (Jul 15, 2008)

Depends on what engine you have and what oil you use. For some engines with top oils 10k may be fine. If you have a 2.0FSI, no way would I go past 5k miles. We have plenty of evidence that the oil is shot by around 5k in those fuel-diluting direct injection engines.


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## epearson (Dec 4, 2005)

I guess I should have added those details. It's a 2.5 and has been run on full synthetic from the factory. I believe they use Mobil 1


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## saaber2 (Jul 15, 2008)

Did a quick search to find 2.5 used oil analyses (UOA), and there aren't many out there I could find quickly. So in the absence of lots of UOAs to give an indication, I would suggest going the 5k route but do a used oil analysis at the end of the run. That UOA will tell you if you can run the oil longer on subsequent runs. This way you will be basing your oil change interval on the specific information from your engine rather than taking it on authority from VW. A UOA with Total Base Number (TBN, one measure of the oil's ability to buffer acids) costs about $33 from Blackstone laboratories http://www.blackstone-labs.com/. It's a very cheap way to see how an oil holds up in your engine and can save you money down the road by using an oil change interval and oil that is best for your car.


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## rickjaguar (Apr 23, 2009)

IMO climate is definitely a factor- hotter outside temps will affect the performance of your car, and using a thicker oil is a good idea. (5W40 instead of 5W30) 
As for the maintenance intervals go- 5000mi is about as high as i'd ever want to go. 
The dealership will say 10k is fine- but in reality their motives are strictly to sell cars to the masses. 

Most peeps (who don't think about maintenance) will compare these dealership service intervals against each other when shopping a car. If car "A" needs servicing every 8k but car "B" is every 10k, more will choose the longer interval (assuming) that means "B" is a better built car. 

All the dealer wants to do is sell cars.. and after the warranty is usually when cars start to show signs of losing their jump they once had. Less than frequent oil changes will start to affect performance. 

I'm of the mindset that an ounce of prevention is worth a pound of cure.


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## rpierson51 (Oct 12, 2007)

DIDDO!


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