Does your Nissan owners manual specify synthetic blend or full synthetic? If not, then you can use the conventional oil.
Synthetic oil goes through an additional refining process. Synthetic blend is a combination of conventional oil and synthetic oil. Nobody has ever really stated what the percentages are for their formulation - and it's not regulated by any law. In theory, a few ounces of synthetic oil, added to conventional oil, and the bottler can label it as "synthetic blend". Nobody except for Chevron can truthfully tell you what the difference is between their conventional and synthetic blend. I don't work there as a chemist. Any opinion would be a guess at best.
As most people will tell you: save $1, Havoline oil will be fine for your daily driving application. You do not have a performance engine. You are not racing. You are not towing heavy loads up steep grades, all day, every day. Your engine is not idling all day, every day, in the desert of Las Vegas or Dubai.
According to Chevron:
Havoline® Motor Oils meet:
• API Service Categories
— SN PLUS
— SM, SL, SJ and all previous API "S" categories
— Resource Conserving for API SN PLUS
(SAE 5W-20, 5W-30, 10W-30)
— ILSAC GF-5 (SAE 5W-20, 5W-30, 10W-30)
• manufacturers' performance requirements
— FCA US LLC (formerly known as Chrysler Group
LLC)
MS-6395 (SAE 5W-20, 5W-30, 10W-30)
— FIAT
9.55535-CR-1 (SAE 5W-30)
— Ford
WSS-M2C945-A (SAE 5W-20)
WSS-M2C946-A (SAE 5W-30)
— General Motors
GM 6094M (SAE 5W-20, 5W-30, 10W-30)