I followed your instructions and found they worked well overall on my 2009 Corolla, with the 1.8 litre engine.
I, myself, am also stuck with a 65/67, which gives me troubles but seems to still work. The main problem with 65/67 is that the cap gets twisted and stuck in the wrench and then it's difficult to remove it from the wrench. Another problem is that during tightening it tends to slip; although, I seem to be able to apply the proper torque. I will also try to find a 65 mm that should be troublefree in comparison with the 65/67.I tried to locate a 65 mm 14 flute oil filter cup or cap tool. I managed to find a 65 - 67 mm 14 flute tool at a local Napa Auto Parts. This is the only tool I could locate locally. It cost about $8.00. It worked good.
I agree a 65 mm without the 67 mm portion of the tool would be a bit better. I did locate on on line and ordered it.
I would never use a non-TOYOTA oil filter or cartridge. From what I heard and read, TOYOTA oil filters outperform even the expensive, premium aftermarket oil filters. They feature double-layer filter elements with coarse and fine media, which allows to trap more particles. There might also be dimensional or sealing problems with the aftermarket cartridges. My local dealer charged me $6.50. The list price at $10.37 is considerably more; so, make sure not to pay the list price and get ripped off. Some dealers like to sell parts at the list price, which they shouldn't.I could only locate a filter cartdridge at the Toyota dealer, no one has them in stock yet being a new car. I went to the Fram web site and tried to locate several they cite made by them and other companies. I did get one at the Toyota dealer ($7.00) they are the only ones that I could find one at.
The only difference between 0W- and 5W- is the cold-engine performance. 0W-20 and 5W-20 are practically indistinguishable when the engine warms up. And for the cold engine, thinner the oil the better it is, regardless of the climate. That's because cold oil is already thick to begin with. Hence 0W- is better for any engine than thicker cold viscosities, such as 5W-, 10W-, 15W-, or 20W-. The hot viscosity (-20, -30, -40, -50) should be chosen according to mainly the manufacturer recommendations and then the ambient temperature and driving habits. I believe the reason why TOYOTA specified 5W-20 as well is because 0W-20 is hard to find and it only exists in synthetic form, which is expensive (about $7 per quart for synthetic vs. $4 per quart for conventional.) Another thing to keep in mind is not to idle or, even worse, race, a cold engine, which tends to harm the seals and rings. A few seconds after you start a cold engine, keep driving without idling to warm up the engine, but drive smoothly and be gentle on the accelerator. This should condition your seals and rings for the cold engine as well and eliminate cold-engine problems in the long run. Idling a cold engine in order to warm it up will only harm it.I used the 5W-20 vice the 0W-20. Reason being is the environment where I live. After reading up on the oils on line and in the car owners manual decided 5W-20 would be best for the ambient temperature range I live in. The oil cap on the engine shows 0W-20 or 5W-20 oil should be used.