Round 05 - Motorsport Arena Oschersleben, Races 9 and 10

Oschersleben: Thiim Limits the Damage as Aston Martin Loses DTM Lead

Three weeks after Nicki Thiim and Comtoyou Racing completed a perfect double victory at the Norisring, the DTM delivered a very different weekend at Motorsport Arena Oschersleben. Thiim qualified 18th and finished 12th in Saturday’s opening race before qualifying 19th, starting 18th and recovering to 13th on Sunday. The Aston Martin driver scored seven championship points across the two races, while Nicolas Baert retired from both in the sister Vantage GT3.

Thomas Preining won Race 1 from pole position for Porsche, while Mirko Bortolotti claimed Sunday’s race for Lamborghini after a strategic drive and a costly second pit stop for Preining. Maro Engel finished third on Saturday and second on Sunday, allowing the Mercedes-AMG driver to take the championship lead from Thiim.

Why Thiim Carried Additional Weight

Thiim arrived at Oschersleben leading the Drivers’ Championship following his two victories at the Norisring. However, the DTM’s success-ballast system meant the #7 Aston Martin carried an additional 20kg during Saturday’s race because Thiim had won the immediately preceding race.

Under the 2026 DTM regulations, the winner of the previous race carries 20kg in the following race, the runner-up carries 10kg and the third-placed driver carries 5kg. The weight applies during the race only and is not used in qualifying or free practice. It also does not accumulate, meaning Thiim carried 20kg rather than 40kg despite winning both Norisring races.

This distinction is important. The additional weight contributed to Thiim’s difficult Saturday race, but he carried no success ballast on Sunday after finishing 12th. His problems in Race 2 therefore had a separate and highly unusual cause.

Race 1: Preining Dominates as Thiim Starts 18th

Thomas Preining placed the Manthey Porsche on pole position for Saturday’s 40-lap race, with Luca Engstler second for Lamborghini and Maro Engel third for Mercedes-AMG.

Thiim could manage only 18th in qualifying. The Vantage GT3 had been one of the dominant cars at the Norisring, but Oschersleben’s different corner profile, the Aston Martin’s Balance of Performance and the 20kg of success ballast created a far less favourable combination.

Balance of Performance, usually shortened to BoP, is the system used in GT3 racing to balance fundamentally different cars through measures including minimum weight, engine output and turbo boost pressure. It is separate from success ballast: BoP applies to the model of car, whereas success ballast is added to an individual driver’s car because of the previous race result.

At the start, Preining retained the lead while Engel passed Engstler into the first corner. Preining initially opened a small advantage, although Engel gradually reduced the gap and remained close enough to challenge through the mandatory pit-stop phase.

The decisive moment came after lap 21, when Preining and Engel stopped for fresh tyres. Manthey completed Preining’s stop cleanly, but Engel’s left-front wheel became jammed during his tyre change. The delay dropped the Mercedes-AMG behind Engstler and effectively settled the leading positions.

Preining completed a controlled start-to-finish victory, crossing the line 1.601 seconds ahead of Engstler. Engel recovered to third, with Lucas Auer fourth and Bortolotti fifth.

Thiim Recovers to 12th

Thiim gained six positions during the race to finish 12th, 25.475 seconds behind Preining. It was a determined recovery from the ninth row, but the Aston Martin never possessed the performance needed to challenge the leading group.

The result earned Thiim four championship points. That limited the damage, but Engel’s third-place finish was sufficient to move the Mercedes-AMG driver ahead in the standings.

Thiim’s Saturday result should therefore not be read simply as a sudden disappearance of the speed Aston Martin had shown at the Norisring. The Vantage carried an additional 20kg during the race and was competing on a circuit with very different characteristics from the short, stop-start Nuremberg street track.

Even with those factors considered, however, the size of the performance shift was significant. Thiim had taken pole position and victory in both Norisring races; at Oschersleben, he was unable to progress beyond the lower points positions.

Baert Retires from Race 1

Nicolas Baert’s opening race ended after 15 laps. The official classification listed the #8 Comtoyou Racing Aston Martin among the non-finishers, completing an already difficult Saturday for the Belgian team.

Baert’s retirement meant Thiim’s four points were Comtoyou Racing’s only return from the opening race.

Race 2 Qualifying: An Extraordinary Tyre Error

Preining continued his domination on Sunday morning, securing a second pole position with a lap of 1:22.400. Engstler qualified second, with Marco Wittmann third and Engel fifth.

Thiim again found himself near the rear, qualifying 19th despite the Aston Martin receiving an increase in permitted turbo boost pressure before the session. He was promoted to 18th on the starting grid following a penalty for Ben Dörr, but the qualifying position was not simply the result of a slow car.

A serious tyre-fitting error had left Thiim’s Aston Martin running with the two larger rear tyres on the right-hand side of the car and the two smaller front tyres on the left. The front and rear DTM tyres differ in width, diameter and rolling circumference, leaving the car effectively uneven from one side to the other.

The consequences extended beyond the car’s physical balance. The differing rolling circumferences produced inconsistent wheel-speed readings, disturbed the anti-lock braking system and placed abnormal loads on the differential. Thiim initially believed he had suffered a puncture, while Comtoyou Racing described the car as effectively sitting crooked.

The differential was subsequently replaced after qualifying. The team was also permitted to replace the damaged qualifying tyres with a new set before the race.

Although the tyre supplier was responsible for mounting the tyres to the rims, the incident inevitably raised questions about the checking process before the car left the garage. What is clear is that the mistake severely compromised Thiim’s qualifying session and left Aston Martin facing another recovery race from near the back.

Race 2: Bortolotti Capitalises on Preining’s Pit-Stop Trouble

Preining initially maintained his lead despite a strong attack from Engstler at the opening corner. The Lamborghini briefly moved ahead, but drifted away from the ideal line and allowed Preining to reclaim first position.

Sunday’s race featured two mandatory pit stops. Thiim was the first driver to stop, with Comtoyou Racing choosing an alternative strategy in an attempt to move the Aston Martin out of traffic and gain positions through the pit sequence.

At the front, Bortolotti extended his opening stint and used the overcut to move from sixth on the grid into second place behind Preining. Engel also benefited from stopping later, while Engstler lost ground following a problem with the left wheel gun during his first tyre change.

A brief rain shower passed over the circuit around half-distance but was not heavy enough to require wet-weather tyres. Preining remained ahead, with Bortolotti gradually reducing the gap to less than one second before the second pit-stop window.

The race changed when the leaders stopped for the final time. Manthey encountered a problem at the left-rear of Preining’s Porsche, costing the Austrian several seconds and dropping him behind both Bortolotti and Engel.

Bortolotti emerged in the lead and controlled the remaining laps to claim the first DTM victory for the new Lamborghini Temerario GT3. Engel finished second, with Preining third and Wittmann fourth. Engstler completed the top five.

Thiim Recovers Five Positions

Thiim’s early first stop and Comtoyou Racing’s strong pit work helped him recover from 18th on the grid to finish 13th. The team completed its two tyre changes in approximately 6.2 and 6.1 seconds, with Thiim praising the Comtoyou crew for its execution after the difficulties earlier in the day. The result earned him another three championship points.

It was another useful recovery, but the Aston Martin was never in contention for the front positions. Thiim’s weekend ended with 12th and 13th-place finishes, a striking contrast with the two poles and two victories secured at the previous round.

Unlike Saturday, success ballast did not contribute to the Sunday result. Thiim carried none after finishing 12th in Race 1. The tyre error during qualifying, the resulting differential problem and the poor starting position provide the more direct explanation for his second difficult race.

Another Retirement for Baert

Baert qualified 20th for Sunday’s race and retired after completing 29 laps. It left Comtoyou Racing without a finish from the sister Aston Martin across the entire weekend. Baert remains 21st in the Drivers’ Championship with two points, both earned through his 15th-place finishes at the Norisring.

Thiim Loses the Championship Lead

Engel’s two podium finishes transformed the Drivers’ Championship. The Mercedes-AMG driver leaves Oschersleben at the top of the standings with 145 points. Thiim remains second with 124 points, 21 behind Engel and one point ahead of Auer on 123. Preining’s victory and third place moved the Porsche driver to fourth with 117 points.

The championship position is less commanding than it was after the Norisring, but Aston Martin remains firmly involved in the title contest. Six races remain, meaning a maximum of 168 points is still available through race and qualifying results.

The next round takes place at the Nürburgring from 14th to 16th August. Thiim will arrive without success ballast for Saturday’s opening race because he finished outside the top three at Oschersleben.

A Difficult Weekend, Not the End of the Challenge

Oschersleben demonstrated how quickly competitive order can change in DTM. At the Norisring, Aston Martin appeared almost untouchable. Three weeks later, Thiim was fighting for the final points positions.

Part of that reversal can be explained. Saturday’s Aston Martin carried 20kg of success ballast, while Sunday’s qualifying was compromised by an extraordinary tyre error that affected the car’s balance, braking electronics and differential. Neither issue alone, however, completely explains the Vantage’s lack of front-running pace throughout the weekend.

The result also highlights the importance of circuit characteristics and Balance of Performance in GT3 racing. A car that excels at one venue may face a very different competitive picture at the next, particularly when success ballast is then added to the equation.

Thiim nevertheless scored points in both races and remains second in the championship. After a weekend in which very little went to plan, seven points may prove valuable when the title is decided later in the season.

The Norisring established Aston Martin as a genuine DTM championship contender. Oschersleben showed how difficult that challenge will be to sustain.