Former karting star McCarthy caused a sensation when, aged just 16, he qualified on the front row of the grid in his first Clio Cup event at his home circuit of Brands Hatch last spring.
He was on the front-running pace many more times during the season and eventually finished as the championship's highest-placed newcomer in seventh overall.
His results also included two breakthrough podium results in the final six races and he is hoping to continue that strong from into 2018 – beginning this weekend (Sat 7/Sun 8 April) when the new season gets under way back at Brands Hatch.
Bromley racer McCarthy, sponsored by Shandon Hotel & Spa, said: “Obviously I have good memories of Brands Hatch from last April but also the final rounds of 2017 there in the autumn when I was on the podium.
“Last year was all about learning and I’m looking to come back stronger this year. My target is the title.”
McCarthy will again race for the Team Pyro squad – its other drivers include two more impressive youngsters in Bradley Burns and Zak Fulk, plus the experienced Daniel Rowbottom and Max Coates.
McCarthy added: “It’s going to be very competitive between us all, but I see that as a positive as we can learn from each other. On saying that, the whole grid is competitive so it’s not just my team-mates who I need to beat!”
Renault Sport’s UK Motorsport Championship Manager Will Fewkes commented: “Jack was something of a revelation in 2017 – he showed just how well drivers of a junior racing age can come in and be immediately competitive and was actually unfortunate not to come away with more podium results. The experience and confidence he will have gained are sure to play to his strengths in 2018.”