Conventional Oil only lasts 3K miles and Synthetic lasts 7.5K?

[jobjohnny]

So I took my 2011 Outback 2.5i Premium into the dealer today to get the ECM reprogrammed and the service manager said I'm due for an oil change. According to the sticker on my windshield, my local garage changed my oil over 5,000 miles ago. I told him that I thought Outbacks can go for 7,500 miles between changes. He replied that yes, they can go 7,500 miles but only when using synthetic oil. If you're using conventional oil (which I used) I need to change it every 3,000 miles.

I called B.S. on his story since right after that he tried selling me a cabin air filter. Little did he know I changed it myself at 12,500 miles. I'm currently at 15,500 miles.

So, any truth to this? Am I risking damage to my car by using conventional oil every 7,500 miles? I saw nothing in my owners manual which would indicate his assertions. I know oil is a hot topic on this message board and I'm prepared for the responses, "You should always use synthetic!!".

[fun2drive]

Folk lore plain and simple. Dino oil vs synthetic oil are both excellent. If I recall my manual for the 3.6L Subaru suggests but doesn't dictate synthetic oil.
The only way to know is to do an oil analysis and see what the results are. When your total base number which is a measure of additives to protect your engine is low like 1.0 your oil is worn out meaning the protection is not there.
That is the only way to tell.
Your dealer might consider your driving severe which the manual I think does say 3000 miles.
Whole can of worms here and I use BITOG.com to help educate myself regarding fluids which engine oil is a main topic.
Hope this helps some...

[AWDFTW]

He has no clue what he is talking about.

[canubaru]

the owners manual in my 97 GT list the oil change interval as 7.500 miles for regular conditions, 3,750 for severe conditions.

i doubt your year is very different, but check your manual.

but considering that the oil companies and car repair chain stores have spent 50 years convincing all of america that oil only lasts 3000 miles, it does not surprise me that he believes what he is saying.

i do not know if my owners manual mentions synthetic oil, but it came from the factory with dino oil.

[485]

I used Mobil1 ep 15000 and changed mine at every 7,500 miles for my corolla. I am at approx 80,000 miles on the corolla. It has no problem at all. In fact, there are oil out there that guarantee 15,000 miles change enterval like Mobil 1 ep and castrol edge with titanium

[iainb]

Tell your dealer to RTFM.

The manual, and service schedule, clearly state to use conventional oil in the 2.5i with a service interval of 7500 miles unless you are doing a lot of towing or other "heavy" driving.

[1bythesea]

Yea, my stealership tried this one. I emailed SOA and their reply was 7500. When I mentioned this to service I got the song and dance of it depends on driving habits. Yes, it does however, my habits are gentle. Will hang onto the email just in case proof is needed.

[seeren]

Originally Posted by jobjohnny

I called B.S. on his story since right after that he tried selling me a cabin air filter. Little did he know I changed it myself at 12,500 miles. I'm currently at 15,500 miles.

So without you letting him know you had already changed it, he saw that you were past due for a cabin air filter and recommended it? Yeah, I'd call BS on that, too.

[crabjoe]

On a previous vehicle, I had oil analysis done on conventional oil. What I found was that conventional oil can easily go 10,000 miles... This was in a diesel pickup that use to tow a boat, that weighed over 14000lbs, on some weekends. I never did let it go past 10K miles between changes, but I had it done multiple times and even though the oil looked really dirty, the analysis always came back good.

[mcbrew]

I use real class IV and V synthetics (RedLine at the moment). In my previous car, a 2009 Scion xD, I towed a trailer a lot, so I was concerned about the lifespan of my oil. Analysis by Blackstone Labs showed that my oil was still going strong at 10,000 miles. I decided on a 10,000 mile OCI because it was easy to remember. I towed a trailer 1 in every 5 miles on that car, which had a zero point towing capacity (in the US). Modern motor oils are very good... Especially synthetic blends (what most "synthetic" oils sold in the US are) as well as full synthetics.