At least, according to these guys.

The Effect of Oil Drain Interval on Valvetrain Friction and Wear

Having said that, I like the peace of mind of a fresh filter... REGARDLESS of how nice the oil is.

 

Interesting story ....
We just bought a BMW 328i and the oil change intervals are every 15000 miles using Castrol 5W40

Seems like a lot of miles between oil changes but ...... maybe not ??

 

Porsche recommends 20,000 mile intervals......

 

I just read where Porsche changed that to 15,000.

 

I'll assume that all of the oil recommendations for these cars call for the use of synthetic grade lubricant. And if that is the case, then 10,000, 12,000, even 15,000 oil change intervals isn't out of the question. Of course, service intervals depend on driving habits, environment, etc. In most industrial facilities, synthetics are used to extend oil change intervals based on oil condition, which is typically sampled and sent off to a lab for anaylsis. Oil isn't changed until it needs to be changed!

 

When synthetic first came on themarket, Mobil was talking 15K on standard 5 qt sump capacity engines.

We are 8.5 Qt

Bigger sumps allow for longer intervals. So I guess by that standard we could do 20-30K

Mobil doesn't brag that 15K anymore so I guess real experience by the auto industry and the oil guys has toned it down.

I'm with JHM2K. I don't care how good the used oil specs out. It has to be clean and it has to flow easily.

Changing the filter is key.