Dillmann drove for the JLOC squad at the first pre-season test of 2020, sharing the team’s #87 Lamborghini Huracan GT3 with Yuya Motojima and Tsubasa Takahashi.
It was his first run in Japan since 2018, when he contested the Super Formula championship with Team LeMans, finishing 14th in the drivers’ standings with a best result of fourth place.
Having been left without a drive since ByKolles left the FIA World Endurance Championship and the NIO Formula E team replaced him with Ma Qing Hua for the 2019/20 season, Dillmann said he is planning to use the test to return to active competition.
JLOC has already revealed the driver line-up for its two Huracans, but factory Lamborghini driver Dennis Lind - who was announced as Motojima’s teammate in the #87 car - skipped Okayama and is not on the entry list for next weekend's Fuji test either.
“My goal was to try to get into GT500 or continue in Super Formula [in 2019], but with Formula E there were too many clashes, so it was impossible to try to get a seat in one of these championships,” Dillmann told Motorsport.com.
“Now I will try again. My goal would be to do GT500, but to be in GT300 would be good to get to know the championship, the races, all the traffic. It would be interesting.
“Also the competition is very high in GT300, very good drivers and teams. Of course the cars are slower, but it’s very competitive, fun and interesting.”
Dillmann has raced in a variety of single-seaters and sportscars in the last five years, and even drove an earlier iteration of the Lamborghini Huracan GT3 during the final round of the 2017 Blancpain GT Series Sprint Cup.
However, he admitted that his lack of experience in GT300 could count against him, particularly because of the four-way tyre war in the series.
JLOC’s Huracans are fitted with Yokohama tyres, despite the brand racing with either Michelin or Pirelli rubber in other GT3 categories around the world.
“I’m used to jumping from car to car, especially in the year I did Super Formula  I was also doing LMP1 and Formula E,” Dillmann explained. “So I’m used to driving many cars. I’m also used to multi-class racing in the WEC.
“I am not very experienced in GT3 cars, cars with ABS, I’m more used to downforce. I think it will be for sure easier to drive GT500 than GT300 because I’m more used to this kind of car.
“But this kind of car, for me the main difference is the tyres, because here there is a tyre war, whereas in Europe everyone has the same tyre. There are a lot of tyres to test and big differences between cars. It’s very interesting.”
Dillmann will not be present for the Fuji test next weekend due to new travel restrictions imposed on arrivals into Japan from Europe amid the global coronavirus pandemic.