Toyota will run a first version of their 2006 Formula One car in Spain today, well ahead of rival teams.
"We have been working on the TF106 since the end of 2004," said technical director Mike Gascoyne in a statement before the start of testing today at Barcelona's Circuit de Catalunya.
"The introduction of this car at such an early stage is a true testament to the work of the team and shows that we are able to react and push forward at a rate that is necessary to be at the forefront of F1."
Toyota were the most improved team of the 2005 season, finishing fourth overall and taking their first podium placings since they entered the sport in 2002.
Champions Renault are not due to run their new car and engine until January.
Gascoyne said the TF106 had an all-new rear, to accommodate a V8 engine after the change in regulations from V10 power this year, with the front end evolved from an interim car raced at the last two grands prix in Japan and China.
"The TF106 that will run in Barcelona marks the first stage of development for this car with continuous improvements planned in the run up to the first race," said the Briton.
"We are adopting a similar schedule to last season by testing the car early. This allows us to develop the mechanical side of the car thoroughly before we introduce a new aero package in time for the first race.
"This strategy helped us to be extremely competitive at the start of 2005 and we are confident the same will happen in 2006."
Toyota had just one retirement due to engine failure in 19 races this year, despite engines having to last for two successive grands prix.
Engine technical director Luca Marmorini said a lot of teething problems had been solved by running the V8 at an early stage.
Toyota said the RVX-06 engine had completed 2,143kms on the track since the end of July.
The 2006 championship starts in Bahrain on March 12.
Zonta signs up for another year as Toyota tester
Brazilian Ricardo Zonta has signed a one-year contract extension to stay as Toyota's F1 test and reserve driver in 2006.
"We enjoyed such a successful year in 2005 and I am sure this trend will continue," he said in a team statement.
"I feel part of the family at Toyota and I would rather continue to offer my services as third driver than become race driver in another series which I may not enjoy as much as Formula One," he added.
Toyota finished fourth overall in the 2005 championship, their best performance since entering the sport in 2002, but the success means they will no longer be allowed to run a third car in Friday practice at grand prix weekends.
Zonta will, however, attend the races as a reserve in case either Jarno Trulli or Ralf Schumacher are unable to compete.
French veteran Olivier Panis will also continue as a test driver, his fourth successive season with the team after retiring from racing in 2004.
Toyota have three scheduled test sessions in Spain before the traditional winter break.