Barrichello has been racing in Formula One for 15 years
Rubens Barrichello will celebrate his record 257th Formula One Grand Prix appearance in Turkey next month, despite disagreement over the figure.
The Brazilian, 35, believes he will equal Riccardo Patrese's record of 256 starts in Sunday's Spanish Grand Prix and pass that mark in Turkey on 11 May.
But because of the complexities of some F1 rules there is confusion over how many races Barrichello has contested.
As a result, other sources have Barrichello on 253 and 252 starts.
The Grand Prix Guide, an annual compiled by Formula One statistician Jacques Deschenaux, put Barrichello's tally at 250 races at the start of the 2008 season - a figure that would make the race in Istanbul his 255th.
According to Deschenaux, a driver is only considered to have contested a race if he takes the first start.
That means the guide does not list Barrichello as having started the tragic 1994 San Marino Grand Prix, marred by the deaths of Ayrton Senna and Roland Ratzenberger, which he missed after crashing heavily on the Friday.
I never thought I was going to be the longest driver in F1 history
Nor does it count the 2002 Spanish and French Grands Prix, which the Brazilian qualified for but did not compete in after problems before the formation lap.
However, it does list the 1998 Belgian Grand Prix, which was re-started without the former Ferrari driver after he was involved in a first-lap accident.
Barrichello's Honda team even had his starts listed as 249 at the beginning of the season - putting him three races short of a setting a new record in Turkey.
However, Honda said in a statement on Monday: "In view of the lack of consensus regarding which specific race marks Rubens' 257th Grand Prix, Rubens will celebrate the milestone at the Turkish Grand Prix."
Barrichello told reporters at the start of the year that he was looking forward to claiming the record.
"As a boy, when I looked over the wall at Interlagos to look at Formula One, I always wanted to be there and to be a race winner," the Sao Paulo driver said.
"I never thought I was going to be the longest driver in F1 history."
Barrichello, who made his debut at the 1993 South African Grand Prix, has won nine races and claimed 61 podium finishes in his career.