British Touring Car Championship leader Colin Turkington topped Tuesday's Snetterton test with his WSR BMW.
The day of running was ostensibly for Dunlop to conduct tyre testing, including comparing the German-made 2015 tyres with the current rubber.
Different tyre compounds, ages and fuel loads made direct comparison difficult, but Turkington's best of 1m57.048s - set in the afternoon - was just over a tenth slower than the effort that put him on the front row for last weekend's Snetterton round.
The improving Aiden Moffat's Chevrolet Cruze was second with 1m57.349s, 1.5 seconds faster than the machine managed in Snetterton qualifying. The time was set on fresh tyres and running in qualifying trim.
Tom Ingram's Speedworks Toyota Avensis had set the pace in the morning, with a 1m57.634s. He failed to improve in the afternoon, but the time was still good enough for third overall.
Alain Menu's BMR Volkswagen Passat was near the front throughout the day and ended up fourth. He and Ciceley Mercedes driver Adam Morgan were the only other runners under the 1m58s barrier.
Jake Hill, who raced in the BTCC finale last year, drove AmD's Ford Focus for the final hour.
He recorded a time of 1m59.461s on new tyres, compared to the 1m59.120s (morning) and 1m59.731s (afternoon) laps of regular driver Dave Newsham, who was concentrating on set-up work.
Just over half the BTCC field participated in the test, with the leading absentees being the Triple Eight MG and Eurotech Honda squads.
Pos Driver Team/Car Time Gap 1. Colin Turkington WSR BMW 1m57.048s 2. Aiden Moffat Moffat Chevrolet 1m57.349s +0.301s 3. Tom Ingram Speedworks Toyota 1m57.634s +0.586s 4. Alain Menu BMR VW 1m57.901s +0.853s 5. Adam Morgan Ciceley Mercedes 1m57.969s +0.921s 6. Aron Smith BMR VW 1m58.133s +1.085s 7. Mat Jackson Motorbase Ford 1m58.296s +1.248s 8. Gordon Shedden Honda 1m58.299s +1.251s 9. Fabrizio Giovanardi Motorbase Ford 1m58.383s +1.335s 10. Matt Neal Honda 1m58.415s +1.367s 11. Warren Scott BMR VW 1m58.432s +1.384s 12. Jack Goff BMR VW 1m58.530s +1.482s 13. Rob Austin RAR Audi 1m58.973s +1.925s 14. Dave Newsham AmD Ford 1m59.120s +2.072s 15. Jake Hill AmD Ford 1m59.461s +2.413s 16. Simon Belcher Handy Toyota 1m59.911s +2.863s 17. Hunter Abbott RAR Audi 2m00.106s +3.058s 18. Dan Welch Welch Proton 2m00.908s +3.860s 19. Ollie Jackson Welch Proton 2m04.256s +7.208s