The NASCAR Cup Series switched from carburetors to electronic fuel injection in 2012.
The 2012 season marked NASCAR’s first full Cup campaign using electronic fuel injection, ending a carburetor era that had lasted since the series’ founding. The first Cup race to use the technology was the 2012 Daytona 500 on February 26, where fuel delivery became computer-controlled rather than dependent on a traditional carburetor.
NASCAR had announced the change during the 2011 season and initially considered introducing it earlier, but the transition was delayed. The 2011 Cup season was therefore the last complete season in which the premier series used carbureted engines. Brad Keselowski became the first Cup champion of the fuel-injection era in 2012.
Fuel injection allowed more precise control of the air-fuel mixture and gave teams improved data and tuning options. It did not mean NASCAR abandoned its traditional engine architecture: Cup cars still used powerful pushrod V8 engines. Another common mix-up is the Xfinity Series, which continued using carburetors for years after the Cup Series made the change.