Yes, it is always good for any car.
no synthetic, the clutch will slip.
FWIW, my Honda dealer here in Mpls told me the Honda brand 0W20 oil is SEMI-synthetic and NOT full synthetic. That seems logical to me because they charge $39 for a 0W20 oil change and to get full synthetic almost anywhere it cost you around $60 for an oil change. Full synthetic Mobil 1 0W20 cost $6.50 a quart at Walmart, so you are already over $33 just for the oil. Add labor and a good filter and your at the $60 mark.
Havoline Synthetic is just as good as any other synthetic.
Yes, you can use synthetic, conventional, or a mix of the two.
Yes, Synthetic oil is synthetic oil no matter who makes it.
Depends on temp and driving conditions. The widest range is 10w40 Honda GL4 oil. Any good synthetic blend oil will work as well.
Yes, you can use synthetic oil in our CR-V - but once you start using it it is best to continue using it at each oil change rather than switch back and forth.
5W20. I would choose a good-quality synthetic - Mobil 1, probably.
Use 10w30 Synthetic.
Honda's 2005 Honda CRF250R takes 660 ml of 10W40 synthetic oil. There are several brands to choose from including Honda's own oil mixture.
If that is the correct weight recommended by Honda then yes you can use synthetic in the place of conventional lube.
10w30 is a good choice year round. I highly recommend you use synthetic oil in this air cooled engine.