Using Lincoln Electric’s Power MIG 140, welding on the M&Ms car.

In the wake of racing legend Dale Earnhardt Sr.'s death in the last lap of the 2001 Daytona 500, NASCAR officials set out to engineer a safer race car.

They also sought to develop a vehicle that offered racing teams more cost-effective development, fabrication and maintenance.

To do that, they crafted precise technical specifications for all racing teams. In essence, NASCAR created the same car for all teams in the competitive Sprint Cup Series - the Car of Tomorrow (CoT) that took its first competitive laps in March 2007 at Bristol Motor Speedway in Bristol, Tenn., during the Food City 500 race.

NASCAR's Car of Tomorrow is the culmination of seven years of planning, development and design at NASCAR's Research and Development Center in Concord, N.C.

The organization's old rules allowed racing teams to fabricate cars on a variety of templates that differed among specific manufacturers.

All Cars of Tomorrow — no matter if they are Ford, Dodge, Toyota or Chevy — now are required to fit the same set of design specifications and undergo inspection to ensure compliance on a standard blueprint.

The larger, boxier Car of Tomorrow design standardizes numerous components across racing teams, ranging from sections of the frame to crumple zones, among other factors.

While Sprint Cup Series racing teams no longer are building completely different cars for different tracks, they've learned there's still room for some chassis customization through competitive-minded construction tweaks that suit a particular driver's style or even the length of the track.

“The Car of Tomorrow narrows the competitive technology gap among teams, but it still exists,” Shane Love, head fabricator at Joe Gibbs Racing, a Toyota team and former home to two-time Sprint Cup champion Tony Stewart, said.

“Racing team fabricators are adding customization to the Car of Tomorrow to boost a team's competitive advantage. It comes down to the chassis. The cars have standard frames and safety features, but there definitely is a small amount of room for tweaks. Welding plays a huge role in that,” Love added.

Standard template

Safety remains the No. 1 reason that the organization sought to build a more standardized Sprint Cup racing vehicle, but NASCAR also quickly realized such a car could improve competition and allow teams to be more cost efficient — with room to personalize the cars to the required style of various drivers and tracks, notes Don Krueger, lead fabricator at NASCAR's Research & Development Center.

“The public perception that these things are so locked in with an assembly line production mindset is overplayed,” Krueger said.

“These cars still are built one at a time. Yes, the Car of Tomorrow specifications have made it a little more ‘assembly line,’ but each car is unique, and teams are making minor changes within the parameters. You certainly don't crank out chassis on an assembly line,” Krueger added.

Under the Car of Tomorrow's detailed specifications, all Sprint Cup Series stock cars must meet the same dimensional specs for the wheelbase — 110 in. — body width — 74.0 in. — body length — 198.5 in. — and height — 53.5 in.. The driver's seat is 4 in. closer to the center of the car. The roll cage is 3 in. closer to the rear. The roof height is 2.5 in. more than what Love calls the “cars of yesterday,” while the greenhouse is 4 in. wider.