Honda EU generator -- which is the best oil temperature range rating?

[Abimotek]

Please below attached which is best oil in my 4 stroke gen set Honda EU 10i, weather temperature attached in my area. I all so have two oil grades > 4T 10w-30 and Coastal Synthetic Blend 5W-30, please advice which will help the life of the gen set

 

[Mech_Engineer]

Why not follow the recommended guidance in the manual? Seems like 10W-30 is what you need.

 

[cjl]

It looks like the 10W30 should be a good choice, though you might want a 10W40 in the future since you're near the upper end of the temperature range for the 10W30.