In 2005 Ralf started a new project with Toyota. He signed a multi year deal and was looking forward to good results with an ambitious team.

The season kicked off in Melbourne and saw Ralf struggling with a lose belt which meant he had to put in an extra stop and ultimately lose a good track position. He ended the race in P12. Malaysia was a solid week-end in which Ralf started and finished the race in P5. Also Bahrain was positive when Ralf finished in
P4 and scored his best result thus far. Back in Europe Formula 1 went on to race in San Marino and Ralf struggled with a train of cars infront of him and ended the race in P9. In Spain Ralf qualified his Toyota on the second row but had to be content with P4 in the race just behind his team mate.

He then went to Monaco and drove arguably his strongest race performance of the year. Michelin screwed up his tyres and Ralf was demoted to last place on the grid. He then went on to plough through almost the whole field and finished in a very strong P6. Monaco, a track where overtaking is virtually impossible.

At the Nuerburgring Ralf made one of his very few driving mistakes and he didn't finish the race. The F1 circus then went on to the North America races in Canada and USA. Canada rewarded Ralf with P6, even if he suffered an unlucky decision by the stewards which saw him lose a lap to the leaders of the race. USA was a nightmare, Ralf had a "Deja Vue" moment and buried his Toyota in the concrete wall on the banking of Indianapolis Speedway. In the second year running he hit the same spot without him being responsible for it. France, UK and Germany gave Ralf more points to his tally with places 7, 8 and 6 respectively. Hungary finally was a breakthrough.

Ralf scored his first podium for Toyota and the signs looked set for a strong 2nd half of the season. Unfortunately the race in Turkey was not so positive when Ralf suffered technical problems which saw Ralf lose a lap and finish the race in P12. The last 2 European races gave Ralf more points as he finished the races in Monza and Spa with the positions 6 and 7 respectively.

Brazil proved to be a very tiring race for Ralf, which he finished in P8 before heading to Japan and China with his team. Japan and China were very good races for Ralf. In Japan he scored a pole position for Toyota, when the weather played into his hands and helped him to pip Jenson for P1 on the grid. In front of his "home crowd" he was able to put the Toyota TF105B on the top spot, but unfortunate events during the race saw him drop back and score a point only. However, in China Ralf made up for the missed opportunity in Japan. Driving a flawless race helped Ralf to score a further podium finish and elevate himself to P6 in the drivers championship.

Thanks to his performance Toyota finished in P4 of the constructor's championship, their best ever position since the beginning of their F1 campaign.