I am getting ready to do my first oil change. The manual is a little unclear on the suggested weight for motor oil. It specifies either 5W-30 or 10W-30. It seems to me that in the temperate Sou. Cal. climate that it isn't necessary to go to an oil that is as thin as 5 weight on the bottom end correct ?
I'm thinking 10W-30 is OK and the 5W-30 is better for parts of the country that experience snow and/or below freezing temperature for a few months per year.
Comments ? Thanks.

 

Its ur call but I use 10W-30 in summer and 5W-30 in winter
I am in NorCal so temps are not too far off.

I suggest using 5w-30 initially as the clearance in the engine will be much tighter, later after 10-15k maybe you can think about going the 10w-30 route.

2003 G35 Black Sedan

 

Try to stick with 5W/30 unless you expect outside air temp. to get over 100. It pumps faster upon startup when almost all wear occurs. If you live in Phoenix or LasVegas, then a 10W/30 or 10W/40 is OK in the summer. Never use 20W/50 in a VQ in any weather. Too thick and doesn't get where it needs to be fast enough.