During the 1988 season, Williams worked with their new engine supplier Renault to develop the RS1 3.5 V10 engine. Williams designed a test mule for the engine named FW12B, very much like the Judd-powered car Williams used for the 1988 season except the mule was designed to accommodate the extra length of a V10 engine and not a V8 like the race cars used. For the season the Renault V10 engine was used. This was the first Renault powered Williams F1 car and also saw Renault's re-entry into Formula One after stopping the supply of their turbocharged engines following the season. The Renault engine was designed under the direction of longtime Renault Sport engineer Bernard Dudot; the design and development of Renault’s V10 started at least a year before Honda began developing their V10 engine largely due to Renault’s short-lived withdrawal from F1 as an engine supplier at the end of the 1986 season. The updated and revised FW12C showed its potential in the season opening Brazilian Grand Prix with Patrese qualifying 2nd and leading the race from the start in what was his 176th Grand Prix start, which was then a record. Patrese also set the fastest lap of the race before retiring in front of the pits with a broken harmonic balancer.