I have to admit I've not found the cabin filter in my Grande Puntos yet, maybe it doesn't have one. The heaters in these GPs cars are very vaiable, they don't quite work, but manage to stop working in stlightly different ways, makes life interesting I guess.
Another of Andy Monty's excellent guides:
https://www.fiatforum.com/guides/how-to-install-replace-the-pollen-cabin-filter.668/
For us older chaps it involves a most uncomfortable wriggle around in the footwell! I'm not sure if non air con cars have them? My boy's 2012 certainly does, damn it!
I watched this documntary on Youtube recently about oil changes. The presenters asked people how often they change oil, then went to dealers and asked them, then took samples of oil from various cars for scientific testing. The testing process was something like what you describe, looking for contaminants. Mostly the documentary presenters showed that dealers do far too many oil changes and the oil they were changing was still clean. They do this because once they have the car they can upsell other products.
I think a lot of the problem with trying to asses whether extending oil change intervals is risky or not is that you've no real way of assessing whether the polymer (what makes multigrade multigrade) is breaking down or the additive package is exhausted or not. For many years I've been obsessed with "rescuing" elderly horticultural machinery - so old cultivator/rotavators, lawn movers, etc. The people who operate these machines are very often excellent gardeners but very ignorant about machinery. Low oil levels, failing to do any maintenance, even oil changes, and using the wrong oils is common along with gross missuse of the machines - failing to empty grass boxes on rotary mowers is a common practice and puts severe strain on these small engines when the blade is trying to recirculate the already cut grass which is spilling back due to the grass box being over full. If you want your machine to have a long life then don't let your grass box get much more than 3/4 full before emptying.
Having run my own grounds maintenance squad for 15 years I've seem the results at first hand. A lot of the locals and people associated with my work, got to know I was a "fixer" of dead or dying machines and ended up on my doorstep asking for help. Many of the machines were quite old which was where my interest in even older machines came from. However, back to the point of this rambling. I much prefer to use a single weight oil in these primitive air cooled engines. Some of the more modern machines I bought for use in my own squad were recommended to run on multigrade with 10w-30 often specified. Older machines (side valve Biggs and Stratton and Tecumseh in particular) are pretty much universally recommended to use straight SAE30. What I found was that when the machines were being used on light duties, so on lawns where the grass was being cut regularly and the grass boxes were being emptied appropriately a multigrade oil worked well. However when a machine was working very hard on "stupidly long" grass perhaps or where the operator was repeatedly failing to empty the grass box when full, the engines running multigrade would fail very often with piston ring and bore damage. The ones running straight 30 weight (or 40 weight if an older machine, to control oil consumption) could get so hot not only the head would be smoking and the paint shriveling up but also crankcases might be too hot to touch. If I caught them quickly enough, set the machine aside to run without load to keep the cooling air flowing - DON'T just stop a very over heated air cooled engine, it needs the airflow - then often, once cooled down, the machine would work normally again. My theory is that the polymer in the multigrade and some of the "fancy" additive package was breaking down. The multigrade oil subsequently removed from such machines was truly "horrible" and burnt whereas the oil from the machines running straight 30 weight still looked like, well, oil! Further research revealed that these simple straight grade oils don't contain much by way of additive packages, so, for instance, most are low detergent. I now fill all these types of engine with straight SAE30 and have no problems. I'm not talking here about more sophisticated machines with pressurized oil systems and oil filters where I'd always use the recommended lube - but engines like these are more usually fitted to really professional machines so are less likely to be abused anyway. I also changed their oil twice during the season. For many years I've run this product:
indeed my own old "Harry" rotary mower, with a very ancient, non standard, Tecumseh side valve runs on this oil and I've never had a machine running on it fail due to a lube problem.
Well, I digressed a bit there didn't I, I'm sure noone who follows my ramblings will be surprised at that. Hope someone found it interesting. Air cooled engines are very interesting lube wise, with their own particular problems - such as localized hot spots and much wider operational heat ranges.
