The four-time title winner took his NAPA-liveried Alliance Racing Ford Focus ST around the East Midlands circuit 0.098 seconds clear of team-mate Dan Cammish in an afternoon session that was effectively ended by a thunderstorm an hour before the chequered flag.
The morning session was dry, but featured generally slower laptimes. Drizzle prevented much meaningful running early in the afternoon before the track dried out for a period of fast laps before the deluge.
Fresh from his win in the Gordon Spice Trophy at Goodwood in a Ford Mustang, Sutton was happy with his progress.
“I’ll be honest with you – we’re just going through a testing programme,” Sutton told Autosport.
“The times are a little bit irrelevant, we’re just going through changes to the car like everyone else.
“Is it the perfect car to go into qualifying with next week? No, but I’m still pleased that we’ve shown strong pace.
“I’m not sure what the others have been up to, but overall I’m happy with where we’re at.”
Source: Autosport