In the early 1980s, teams were switching from the General Motors 1971–77 X-Body compact cars with 311-cubic inch engines. Later, teams were using General Motors 1982–87 G-body cars. Ford teams have used the Thunderbird cars consistently. In 1989, NASCAR changed rules requiring cars to use current body styles, similar to the Cup cars. However, the cars still used V6 engines. The cars gradually became similar to Cup cars. In 1995, changes were made. The series switched to V-8s with a
compression ratio of 9:1 (as opposed to 14:1 for Cup at the time). The vehicle weight with driver was set at 3,300 pounds (as opposed to 3,400 for Cup). The body style changes, as well as the introduction of V-8s, made the two series' cars increasingly similar. The
suspensions, brake systems, transmissions, were identical between the two series, but The
Car of Tomorrow eliminates some of these commonalities. The Car of Tomorrow is taller and wider than the
Generation 4-based vehicles in the then-Nationwide Series, and until 2010, it utilized a front "splitter", opposed to a front valance. The Car of Tomorrow also set
pole speeds slower than the NOAPS cars at companion races. Previously, Busch Series cars used
fuel that contained lead. NASCAR conducted a three-race test of unleaded gasoline in this series that began on July 29, 2006, with a race at
Gateway. The fuel,
Sunoco GT 260 Unleaded, became mandatory in all series starting with the second weekend of the 2007 series, with Daytona being the last race weekend using leaded gasoline. Another distinction between the cars started in 2008:
Goodyear had developed a
rain tire for NASCAR
road course racing in both series but NASCAR had yet to use them under race conditions by the time NASCAR abandoned the program for the Cup Series in 2005 (the Cup Series eventually used rain tires at the
2020 Bank of America Roval 400 and
2021 EchoPark Texas Grand Prix), but the Busch Series continued to use rain tires in races at
Autódromo Hermanos Rodríguez and
Circuit Gilles Villeneuve, since the races could not be planned with rain dates. When rain started to fall at the
2008 NAPA Auto Parts 200, the tires were used in the rain for the first time. Another distinction was added in 2012, when NASCAR changed the fuel delivery system in the Cup cars from carburetion to
fuel injection. NOAPS cars continue to use carburetors. Furthermore, with the Cup Series' switch to
Next Gen car in 2022, O'Reilly Auto Parts cars (as well as Truck Series vehicles) continue to use traditional five-lug steel wheels and centered door numbers, as opposed to an aluminum center lock wheel and numbers being placed behind the front wheel on the Next Gen.
Specifications for Generation 4 NOAPS car to inspect
Casey Atwood's 2004
Chevrolet Monte Carlo. •
Chassis: Steel tube frame with integral safety roll cage – must meet NASCAR standards •
Engine displacement:
Pushrod V8 •
Transmission: 4-speed
manual •
Weight: minimum (without driver); minimum (with driver) •
Power output: 650–700
hp (485–522 kW) unrestricted, ≈450 hp (335 kW)
restricted •
Torque: •
Fuel: 90 MON, 98
RON, 94 AKI unleaded gasoline provided by
Sunoco 85% + Sunoco Green Ethanol E15 •
Fuel capacity: •
Fuel delivery:
Carburetion •
Compression ratio: 12:1 •
Aspiration:
Naturally aspirated •
Carburetor size: 390 ft3/min (184 L/s) 4 barrel •
Wheelbase: •
Steering:
Power,
recirculating ball •
Tires:
Slick (all tracks) and
rain tires (road courses only if in case of rainy conditions) provided by
Goodyear Eagle •
Length: •
Width: •
Height: •
Safety equipment:
HANS device,
seat belt 6-point supplied by Willans
Xfinity "Car of Tomorrow" (CoT) The then Nationwide Series unveiled its "Car of Tomorrow" (CoT) at the July 2010 race at
Daytona. Before being fully integrated in the 2011 season, it was also used in 2010 races at
Michigan,
Richmond and
Charlotte. The Xfinity CoT has important differences from the NASCAR Cup Series
CoT, and the now-retired Generation 4 style car. The body and aerodynamic package differs from the NASCAR Cup Series cars, marketing American
pony cars from the 1960s such as the
Ford Mustang,
Dodge Challenger, and
Chevrolet Camaro. The change to share the same CoT chassis as the Cup series resulted in the wheelbase being lengthened from 105 to 110 inches Each manufacturer uses a distinct body design (similar to 1960s muscle cars), built within strict aerodynamic guidelines provided by NASCAR. The
Chevrolet car body currently resembles the
SS, after initially running the
Impala and then the
Zeta-based Camaro (which coincided with GM's Cup car being its four-door Zeta counterpart, the
Holden VF Commodore-based
Chevrolet SS, being used in Cup at the time); Camaro branding was removed after 2024 due to Chevrolet discontinuing the car, though it remains eligible under NASCAR homologation rules.
Ford uses the
Mustang Dark Horse.
Toyota runs the
Camry, reconfigured in 2015 to resemble the current production model. Toyota announced they would be running the
GR Supra starting in 2019, replacing the Camry, which had been run in the series since Toyota joined the Xfinity Series in 2007.
Dodge teams used the
Challenger R/T model, despite the manufacturer pulling all factory support after 2012 (though it continued in Canada as FCA Canada supported the Pinty's Series until 2020). Following Dodge's exit, smaller underfunded teams continued to run second-hand Challenger chassis without factory support (thus earning the nickname "Zombie Dodges"). As a result of a rules change after the 2018 season, all Challenger bodies were rendered ineligible for competition, as the series made the switch to composite body panels. Since FCA had pulled factory support years earlier, no new body was submitted for competition, ending the possibility of running a Challenger body in the series. ==Manufacturer representation==