When NASCAR Stopped Using Carburetors

NASCAR’s top-tier Cup Series stopped using carburetors after the 2011 season, debuting electronic fuel injection (EFI) at the 2012 Daytona 500. While “NASCAR” can refer to multiple series, the landmark shift occurred in the Cup Series, ending a carburetor era that began with the sport’s inception in 1949.

What Changed and When

The 2012 season marked a turning point for NASCAR’s Cup Series as teams replaced carburetors with a standardized EFI system. The last carbureted Cup race was the 2011 season finale at Homestead-Miami Speedway on November 20, 2011—won by Tony Stewart, who clinched the championship that night—closing out more than six decades of carbureted stock cars.

The Final Carbureted Race and the First EFI Event

Homestead-Miami’s 2011 finale was the final outing for carbureted Cup cars. Two months later, the 2012 Daytona 500 became the first points-paying Cup race to run EFI. NASCAR partnered with McLaren Electronic Systems (now McLaren Applied) for the control unit and with semiconductor partner Freescale (now part of NXP) as the series adopted Sunoco E15 fuel.

Why NASCAR Switched to EFI

Electronic fuel injection aligned the series with modern automotive technology, improved fuel metering and reliability, and expanded the scope for tightly controlled, series-wide data logging. The change also dovetailed with NASCAR’s move to ethanol-blended fuel and its push for technical relevance to manufacturers and fans.

Key Milestones in the Transition

The following list outlines pivotal moments and elements in NASCAR’s move from carburetors to EFI in the Cup Series, providing a concise timeline and context for the change.

• 1949–2011: Carburetors define NASCAR’s Cup Series, from “Strictly Stock” origins through the end of 2011.
• 2011: NASCAR conducts EFI tests and validation with teams ahead of full adoption.
• Nov. 20, 2011: Homestead-Miami hosts the final carbureted Cup race; Tony Stewart wins and secures the title.
• Feb. 2012: EFI debuts at the Daytona 500; standardized ECUs and data systems roll into competition.
• 2010s–present: EFI remains in place across the Cup field; the 2022 Next Gen car continues with EFI and modern electronics.

Taken together, these milestones chart a deliberate evolution from heritage hardware to modern, tightly regulated electronic systems that now underpin Cup Series engine management.

Common Misconceptions

Because “NASCAR” encompasses multiple national series, some fans conflate timelines. The widely cited transition date—2012—specifically refers to the NASCAR Cup Series. NASCAR has since standardized EFI across its national tours, but the Cup Series move in 2012 is the benchmark most often referenced.

Impact on the Sport

EFI brought precise fuel delivery, improved engine management, and standardized electronics that enhanced technical parity while preserving NASCAR’s core ethos. Series rules continue to prohibit driver aids such as traction control, and the spec ECU is locked down to prevent illicit automation. Teams gained richer data for reliability and strategy without undermining the competitive, human-driven nature of the racing.

Summary

NASCAR’s Cup Series ended the carburetor era after the 2011 season and adopted electronic fuel injection starting with the 2012 Daytona 500. The shift modernized engine management, aligned the sport with contemporary automotive technology, and set the template for the electronic systems that continue to power the series today.

What engine was banned from NASCAR?

NASCAR has banned several engines throughout its history, but two prominent examples are the Ford 427 SOHC Cammer due to its advanced single overhead camshaft design, and the Chrysler 426 Hemi because of its overwhelming dominance, which led to fears of uncompetitiveness. Additionally, the engine in the 1969 Chevrolet Corvette Grand Sport was also banned, not due to rule-breaking, but because GM corporate policy prohibited its factory entry into the competition.
 
The Ford 427 SOHC Cammer

• What it was: A high-performance V8 engine with single overhead camshafts (SOHC) and electronic fuel injection, designed to compete with Chrysler’s Hemi. 
• Why it was banned: NASCAR banned overhead camshaft (OHC) engines, making the Cammer ineligible for stock car competition. 
• Aftermath: Ford shifted its focus to drag racing, where the engine became a legendary and dominant force. 

This video explains why the Ford 427 SOHC Cammer was banned from NASCAR: 38sRare Car StorysYouTube · Feb 12, 2025
The Chrysler 426 Hemi 

• What it was: An incredibly powerful and compact engine that quickly achieved a high level of success in NASCAR. 
• Why it was banned: The Hemi’s dominant performance was so overwhelming that it was banned to “level the playing field” and restore unpredictability to races. 
• Aftermath: The ban wasn’t permanent, and the Hemi was allowed back into NASCAR after rules were revised to ensure its availability in production cars. 

You can watch this video to learn about the history of Hemi engines in NASCAR: 55s4 Wheels ChroniclesYouTube · Sep 23, 2023
Other Notable Banned Engines 

• Smokey Yunick’s “Mystery Motor”: This advanced Chevrolet engine was banned by NASCAR before it ever raced, though not for breaking rules but due to the potential for it to completely rewrite the sport’s history.

What was the last car sold with a carburetor?

The 1994 Isuzu Pickup (or Faster) was the last vehicle sold in the United States with a carburetor, featuring a basic 2.3-liter engine. While several other models used carburetors through the early 1990s, the Isuzu Pickup held out longer than most, with its fuel-injected successor appearing in 1995. 
Why did carburetors last longer in some vehicles? 

• Base Models: Carburetors often remained in the basic, rear-wheel-drive versions of some trucks and SUVs because they were cheaper to manufacture and required less complex electronics.
• California Emissions: Stricter emission standards, particularly in California and later nationwide through OBD-II requirements, pushed manufacturers to switch to fuel injection, which is more efficient and better at controlling emissions.
• Engine Simplicity: Some engines, like the Isuzu’s 2.3-liter, were simple and robust, making a full conversion to fuel injection a later priority compared to more complex, high-performance vehicles.

What replaced carburetors?

• Fuel Injection: Fuel injection systems provide more precise fuel delivery, improving fuel economy, increasing power, and lowering emissions. 
• Computerized Control: Fuel injection systems use computers to adjust fuel and air ratios based on various operating conditions like temperature and altitude, making them far more adaptable than carburetors. 

When did NASCAR get rid of carburetors?

2012
Starting in the 2012 NASCAR Sprint Cup Series season, carburetors have been officially replaced with fuel injection – making the technology legal after 55 years of being “outlawed.” The first race in NASCAR Sprint Cup Series history to use fuel injection was the 2012 running of the traditionally carburetor-friendly …

What year did the carburetor go away?

Carburetors went away from new passenger vehicles in the United States mostly by the early to mid-1990s, with the last ones being sold around the 1990-1991 model years in certain models like Buick and Oldsmobile station wagons and the Jeep Grand Wagoneer. The transition was driven by stricter emissions and fuel economy standards that required the precision of electronic fuel injection systems, which became standard by the early 1990s.
 
Why Carburetors Disappeared from Cars

• Emissions Standards: Opens in new tabCarburetors couldn’t provide the precise fuel-air mixture needed to meet increasingly strict pollution control standards, especially with the introduction of catalytic converters. 
• Fuel Economy: Opens in new tabFuel injection systems offer better fuel control and efficiency compared to carburetors, leading to improved gas mileage. 
• Advancements in Technology: Opens in new tabFuel injection, particularly electronic and direct injection, became more sophisticated, reliable, and ultimately more powerful and fuel-efficient, making the mechanical carburetor obsolete for mass-produced cars and trucks. 

Last Carbureted Vehicles in the US

• Late 1980s: Many manufacturers had switched to fuel injection by the mid to late 1980s. 
• Early 1990s: Some specific models, like certain Buick and Oldsmobile station wagons (e.g., Custom Cruiser, Estate Wagon), the Cadillac Brougham, and the base Honda Prelude for the 1990 model year, were still sold with carburetors. 
• 1991: The Jeep Grand Wagoneer and the Ford Crown Victoria Police Interceptor with the 5.8L V8 engine were among the last new vehicles to use carburetors. 

Carburetors Today
While gone from cars, carburetors are still in use today for: 

• Small Engines: Found in lawnmowers, generators, and similar equipment.
• Motorcycles and ATVs: Many new models still feature carburetors.
• Piston-Engine Aircraft: Some aircraft continue to use carburetor systems.