Generation 6 (NASCAR)

Throughout the 2014, 2015, and 2016 seasons, NASCAR implemented different downforce and aero packages to promote passing and give their fans more interesting racing.

The car had a low downforce package at the 2015 Quaker State 400 at Kentucky Speedway[12] and another at the 2015 Bojangles' Southern 500 at Darlington Raceway.[13] This package took 1,000 pounds of downforce away from the car. The cars had a high downforce package in July for the 2015 Brickyard 400 and in Michigan. These races saw almost no action and the down force package was criticized by the many fans. Martin Truex Jr. told USA Today: "We could run anybody down and get to them, but it took a long time to pass cars. It was just so damn hard to pass. I could run a guy down from way back and get to him and about spin out. It’s no fun to race like that. We had a car that could have contended with the 20 (Kenseth) today and just couldn’t ever get there."

The major differences between the 2015 and 2016 cars are the shortened spoiler and splitter to give the car less downforce and therefore grip in the turns. Following year's base package includes a 3.5-inch spoiler (currently six inches), a 0.25-inch front leading splitter edge (currently two inches) and a 33-inch wide radiator pan (currently 38 inches; it was 28 inches at the Darlington and Kentucky races).[14]

To improve passing on high-speed tracks, aero ducts[15] were implemented for the 2017 Indiana 250 to alleviate the drag rise on a close trailing car.

The Generation 6 car features additions of forward roof bar and center roof support bar to the roll cage to reinforce integrity and increase the crush structure of the roof. Larger roof flaps help to keep the car on the ground to prevent it from flipping whilst going backward at high speeds.[16]

Despite these safety improvements, there have still been multiple instances of the Gen-6 car flipping during high-speed crashes. At the 2015 Coke Zero 400 at Daytona, Austin Dillon's car went airborne during a multiple car pileup on the final lap and ripped a catchfence. Five spectators were injured while Dillon walked away with a bruised tailbone and forearm.[17] On the final lap of the 2020 Daytona 500, Ryan Newman's car was spun out by Ryan Blaney, sending it to the frontstretch wall and in the air before being broadsided on the driver's side by Corey LaJoie on its way down.[18] Newman survived the crash with serious injuries.[19]

The car's new hood and deck lid are composed of carbon fiber. To alleviate carbon fiber's tendency to splinter and shatter with extreme impacts, Kevlar is incorporated.[20] With the exception of the carbon fiber rear deck lid, all body panels are produced by the manufacturer and individually stamped for verification.[16]

In a move to make race cars closer in style and appearance to modern street vehicles,[21] all NASCAR Cup Series cars began utilizing a digital dash sold by McLaren in 2016.[21] This dash includes 16 customizable preset screens,[20] allowing the driver to monitor all the previous info with several additional elements such as lap time and engine diagnostics, for a total of 24 data elements. Information can be displayed as a gauge, numeral, bar graph or LED.[22]

Future plans for the display capabilities include information such as flag status, restart order and penalties, allowing all such information to be available instantly to the driver.[22] Ultimately, NASCAR could use the digital dash to transmit driver biometrics and provide information to the fans. It is NASCAR's position, however, not to move toward real time telemetry.[23]

Although the car was liked by drivers such as Jeff Gordon, other drivers were critical about the new car. During the 2013 season, Denny Hamlin rallied from the rear to third place where he finished. He commented on how the newer Generation 6 cars were too difficult to pass with. Hamlin stated: "I don't want to be the pessimist, but it did not race as good as our generation 5 or regular CoT cars did." Comments from drivers, like Hamlin, were also similar to those said when the Car of Tomorrow came out. Many drivers stated that it was hard for the teams to figure out how to get the aerodynamics correctly balanced.

Hamlin was fined $25,000 for his comments on the new Generation 6 car. NASCAR spokesperson Kenny Tharp stated, "While NASCAR gives its competitors ample leeway in voicing their opinions when it comes to a wide range of aspects about the sport, the sanctioning body will not tolerate publicly made comments by its drivers that denigrate the racing product."[25]

Fan response to the new body design was positive, as the perception that the race cars in the Cup Series "are cars that I would be interested in buying" increased from 49 percent to 76 percent.[24] However, towards the end of the Gen. 6's tenure, many fans became dissatisfied with the car, in part because of several rule changes made by NASCAR affecting the performance of the car.

The Car of Tomorrow had roughly $10,000 in sheet metal per car, which is $5,000 less in comparison to the $15,000 worth of sheet metal of the Generation 6 car. On average, a well-funded team produces about 50 bodies per car which could lead to a possible issue of being over the estimated budget for this particular category.[26]

With the introduction of the Generation 6 car, there were multiple new requirements. One was a new rear camber, which meant new suspension components. NASCAR's new weight rules required a new lighter-weight chassis. Those changes came with a hefty price, as they increased the cost per car by $500,000 for the season. Including the other changes, the total cost for the season per car was estimated to have increased by $750,000 over the Car of Tomorrow.[26]

The price increase led team owner/driver Tony Stewart to tell reporter Marty Smith the Gen-6 car is financially "great for NASCAR, not for the owner. There's a lot of added cost, a lot of parts that are a lot more expensive than in the past. But racers are very resourceful. These teams will find a way to make it work."[26]