I would use synthetics in a car that put particular stress, especially heat, on the engine oil. The example that comes to mind would be turbocharged or supercharged cars. Other than that, I’d just change regular dino-oil every 3k-5k miles.
I drive an 07 maxima and use the regular—the car does not get the mpg claimed by the manufacturer—gets 23.5 on hiway and I think was supposed to get 26 mpg. I use whatever 5W30 is on sale and have always changed it myself. Funny thing is the car has 30K miles on it now and about every 5K more miles on the engine, the mpg goes up about another 0.1 mpg.
Conventional oils work well with lower-revving engines but synthetics work better with today’s smaller, higher-revving engines, which tends to break down oil faster. That’s why I use Mobil 1 for my 1998 Honda Civic HX CVT coupe, especially since the engine runs a lot at 3,000 to 3,500 RPM all day.