If you're talking about engine oil, you may want to stick with the factory grade of 5W-40. Regular oils are less expensive, while synthetics offer better heat resistance and longevity.

 

When using Synthetic MOTOR Oil what are the Choices here . Should I use the standard dept store type like Castor oil , Valvoline ect or use Red Line, Ams oil. or Purple?????

 

Ah, which synthetic oil to use is a completely separate question! Start by reading parts of this excellent thread:

https://my350z.com/forum/engine-and-...-and-info.html

It's a personal choice and based on my own UOAs, I use Mobil 1 synthetic in my own street and race Zs.

 

It really depends on your budget. Most folks agree that synthetic oils are better to help the engine last longer but they cost more. People think they have validation to believe one brand is best, but this argument has been around as long as engine oils. Do NOT use the recent recommendation from the once per year oil change.

Red Line has an excellent reputation, Royal Purple does not. The others fall in the middle.

Your oil change interval is way more important than brand-
For conventional oils no sooner than 3K miles, no later than 5K.
For synthetics, no sooner than 5K, no later than 7K.

These are general guidelines for cars driven weekly.