2017+ FIAT 124 Spider General Discussion Forum
I found today this article that is an AAA research that really confused me.
https://newsroom.aaa.com/wp-content/uploads/2019/06/Premium-Fuel-Phase-II-Research-Report-FINAL-2.pdf
They used Jeep Renegade 1.4 L MULTIAIR (same motor like 124)
According to this 98 RON will cause less power on our car.