Changed My Crz Gear oil with Honda Gear oil yesterday. 97,000 miles . 2011. may never have been changed. was notchy, now shifts like a Honda..butter smooth.. I find it interesting my last honda stick, a 1995 Accord the Owners Manual read any 10w 30 motor oil was fine. And my 3 Honda Motorcycles use the same oil for the pistons as it does the gears. Goldwing gears do not care.
Alas, I paid my $10 a quart for peace of mind.
My Drain plug and Filler cap were so tight I thought I would break my Craftsman 3/8" ratchet using a pipe extension. Thankfully they broke lose first. It took me 10 minutes to drain and fill on my 1985 Accord..this CRZ change took over an hour.
I was thinking the same thing, 10W30. I also want to echo what you found when trying to loosen the drain and fill. Those were WAY tighter than needed. Should be much easier the next time for both of us.