OCI - Time vs. Miles

[Ddub]

Starting at 2.5K for the FF and working up through 5K and 6K oil change intervals, I have slowly but surely worked my way up to a 7-7.5K mile OCI on my wife's 2010 Mazda 6i Touring consistently using Pennzoil Ultra 5W-20 for the last 2 OCIs and premium oil filters since day one. I plan to continue in this manner and have no immediate plans to get a used oil analysis. Although the 3yr/36K bumper to bumper warranty is about to expire, I will be under the powertrain warranty for the next couple years. The manual suggest oil changes at 7.5K OR 6 months, whichever comes first.

My question:
Currently, using a 7-7.5K OCI puts me on an average oil change interval of 8-9 months. Are there any issues (related to the warranty or just in general) of exceeding the 6 month recommended OCI if I am still inside the 7.5K mile mark? Thanks in advance for your opinions.

 

[gfh77665]

None whatsoever.

 

[Danh]

There is a warranty issue. If service recommendations in the manual call for an oil change interval of 6 months or 7,500 miles, it means exactly that. If getting to the 7,500 mile mark takes longer than 6 months, change the oil at 6 months to preserve the warranty.

If you use a premium oil like Ultra, you could probably go for a longer OCI both in time and miles, but the manufacturer probably won't accept a longer interval. Just change the oil at the earlier of 6 months or 7,500 miles while you're under warranty.

 

[bigjl]

Originally Posted By: gfh77665
None whatsoever.



As second reply states it will potentially invalidate warranty coverage.

It probably won't make much of a difference to the engine which might be what gfh was referring to.

 

[jegs]

The time ceiling is recommended because as oil ages through use the acidic level goes up which in time will start to attack engine bearings etc. I would go by the auto manufacturers recomendations especially on a brand new vehicle under warranty.

 

[Ddub]

You guys are telling me what I kind of suspected, but wasn't really sure. Thanks!