I can add 2 counter arguments.
You never get all the old oil out of your engine on a standard oil & filter change..., so you must accept that there is going to be a small amount of old oil mixing with your new oil. Suzuki say "2.3L without filter, 2.7L with filter, 3.1 Litres after overhaul" for the wee.
So what we're actually faced with is a decision between 0.4 litres of old oil verses 0.8 litres of old oil.
Filter performance verses useable life.
I read on the web where some bloke looked into the different types of filter and how they work, using a new camera microscope their company had purchased. OEM & aftermarket filters are the folded paper type, which if looked at under a microscope are actually a random 3D lattice of fibers which give irregular holes of various shapes & sizes. This bloke measured a few and they seemed to range from 100 to 20 microns.
Anyway, the theory is that as a filter of this type gets used, more & more of the holes trap particles of dirt and thus more of the larger holes get partially or fully filled. If you graphed this out over time you would see that the flow starts to become more restricted but the average particle sizes getting through also reduces.
So, as the filter ages it gets better at filtering because it starts to trap more & more of the larger particles. This continues but at some point you draw a line because the flow restriction increases to the point that it would drop below minimum spec, so you change the filter before reaching this point. Suzuki may have calculated the optimal change point to every 3rd oil change and following this instruction might result in a cleaner engine with less wear.
