Let's say you use your Fram Ultra or Mobil 1 EP for 2 or even 3 oil changes...

Do you remove the filter and drain out the old oil from the filter as well, or just drain the engine and let the little amount of oil in the filter mix in with the new engine oil?

leave the filter on. the seal is one time use

Leave it on. The filter gasket isn't made to seal, come off, and then seal again.

As others have said, leave it on.

I loosen the filer, then re-tighten. Many vehicles today are designed so the filter sits in a manner where half of it's contents will depart. Also a number of vehicles exist today that are designed with oil channels that sit right above the top of the filter threads. These oil channels will empty also.

So in most cases today, no need to remove the old filter, then re-tighten it. Just loosen it half-way, then tighten it.

Also, I don't oil my filter gasket, when I initially install it new. I use Gorilla Grease on the gasket and there's no need to apply anything more to the gasket, when re-tightening it. That particular grease is like an anti-seize lubricant. So it eases removal.

I would never use any filter for more than one oil change, but I would like to see pics of a a filter from that situation

There are multiple threads with cut open oil filters that were used for more than 1 OC.

Tons of cut and post threads of oil filter from multiple OCIs.

Leave it on in between.

Leave it on. I asked this specific question to a FRAM representative. They said not to take it off because the seal can only be used once. The warranty on their filter is also void if you take it off between OCI's because the gaskets seal is compromised.

I did that with a mobil 1 extended. I have one more filter left. I drained the oil, refilled and left the filter on. I will replace the filter the next oil change before I hopefully trade it in

An oil filter used for two 5,000 mile oil change intervals will look absolutely no different from an oil filter used for one 10,000 mile oil change. Oil change intervals doshould not dictate the oil filter change interval. The filter change interval should be commensurate with the type and quality of the filter.

As I have stated before, the State Fleet Admin ran tests years ago and determined that the most cost effective strategy to long tern vehicle ownership is oil changes every 6K and filters every other time. There are also paper over in technical that describe the benefits of retained oil at the time of change. the consensus is that 10~20% retained is best.

This has to do with AW compounds that your engine makes as oil ages in the motor. Fresh oil has none of these. 80% replacement will get the TBN back up and the oil clean enough. and the benefits of the retained oil will do until the new stuff has had a chance to make some.

So I'm going at least two changes. Shannow and I are changing the filters a week or two after the second oil change so that the retained is doing its job.

The life of filters and oil are not coincidental. Changing both is a matter of convenience for the guy on the ground or in the pit. Oil gets dirty, contaminated with chemical by-products of combustion, changes it viscosity by shearing, etc. Only the dirty part impacts the filter. And it takes a lot more dirt and soot than one OCI to do in a filter.

Ideally filters would be changed like in marine and stationary when the differential gauge pressures on both side said they needed to be changed. The oil would be changed based on UOA's. In this scenario, the two never coincide. Cars are just done the way they are because of convenience and caution ...

Sounds like a recipe to make a mess and get contaminants into the system/seal. If I went thought the trouble to mess with it I'd simply change it.

Have you ever provided a link to this report?

California OFAM follows this (oil and filter changed every 6,000 miles or 6 months normal use, or 4,000 miles severe use): https://www.documents.dgs.ca.gov/dgs/fmc/gs/ofam/dgsofam0035.pdf