Hey, I missed some replies, sorry about that. Long weekend here in Ontario.
No worries on the peanut gallery or anything else. I like hearing some ideas that aren't my own. Glad you mentioned the spark plugs and other stuff.
Ok... fuel I use is always the 87 octane regular. I don't tend to stick to one gas station or brand, maybe some of the major ones versus one-offs though. Esso, Pioneer, Petro-Canada. Those are the ones there are lots of in my area, so that's where I go. Most have the "up to 10% ethanol" blurb on the pump, so I'm at the mercy of that kind of blend.
I use the regular oil in the car, not synthetic. 5W30. And admittedly, I go past 5,000 miles in between changes. Not down to when the oil life monitor warns you (never actually seen that warning come on, but assume there is one <10%). Looking back at my notes, I last changed the oil in January (7 months ago) and about 9,000 km ago. Previous to that was about 8 months and 13,000 km, and 8 months and 11,000 km before that one.
Last time I got an oil change done, the shop put some kind of additive can in with the oil. This being the one that adds $20 to your bill and the one they profess is great and we always use it. They put it in before asking me, as I was also in getting the original error code I had looked at (ABS sensor back then). That irked me about not asking, so I've not gone back. I don't imagine the additive was awful, waste of money maybe, but it might have loosened something up. Not sure really.
You're right about the emissions program being mostly cash grab. And yea, it didn't apply to smaller communities north of the big cities. I guess their air is good enough as is? I don't know all the details about what happens if/when you get a fail or conditional pass. There's some kind of "spend a certain amount of money to show you tried to fix it" routine, so $450 could be it. If it's $4k, the car will be going bye-bye.
I'll get the oil changed this week, with regular 5W30 no additives (unless told otherwise?) and I'll also do the spark plugs. I haven't searched yet, but assume changing spark plugs on the V6 G8 is not too difficult? I do absolutely everything I can on my DeLorean (hobby and all), but rarely do much on my own on the G8. Not because I can't, I just never tried to much before. I don't have any tech manuals or shop manuals for the G8 like I do the DeLorean. Spark plugs shouldn't be too tough, assuming not too much has to come off the top of the engine to get to them? I see 2-packs of Bosch Iridium spark plugs for $20.99 at Canadian Tire. They look about like what the originals were, yes?