With a series of larger-scale enhancements in recent years — the additions of stage racing and major modifications to the postseason format — the theme to 2018’s rules update from the NASCAR Research & Development Center relies on a defter touch.

Advancements in inspection technology, a streamlined system for pit stops and standardized at-track personnel sizes and the introduction of the Chevrolet Camaro ZL1 for the Monster Energy NASCAR Cup Series are among the highlights in this year’s update. Other changes governing car specifications and improving safety are numerous but more subtle, an evolution of the updates that have preceded them.

“The past couple years, we’ve had quite a few changes, so in this year, we’re kind of heading more into a stabilization mode,” said Gene Stefanyshyn, NASCAR Senior Vice President for Innovation and Racing Development. “We’re pretty happy with the racing that we have on the track.”

FIRST LOOK: 2018 inspection process

In the Monster Energy NASCAR Cup Series, the most noticeable vehicle change will be the introduction of the Camaro ZLI, which replaces the outgoing Chevrolet SS model. The new Chevy made a splashy debut in Detroit last August and will get its first taste of competition later this month at Daytona.

For Stefanyshyn, it’s a project with personal roots that span back to his time as an executive with General Motors.

“It does pull a bit at my heartstrings because I was responsible for the 2010 Camaro, which had been in hiatus for five years,” he says. “I was fortunate enough to run that project and put it back on the street. It’s very good to see the evolution of it.”

The recent trend of reducing vehicle downforce will continue, but without altering spoiler heights. The aerodynamic shifts will be achieved through use of a common splitter and radiator oil cooler, which Stefanyshyn says will drop downforce by approximately 225 pounds (185 in the front, 40 rear) to a level of 1,650 pounds.

RELATED: Chevrolet unveils Camaro ZL1

But the body changes have also extended to the realm of safety, with a superspeedway liftoff reduction to keep vehicles in all three national series from becoming airborne at NASCAR’s fastest tracks. The latest adjustments have added an estimated 30 mph to the liftoff threshold, Stefanyshyn says, in an effort to help reduce rollovers.

Other safety enhancements currently in development include a high-speed on-board camera designed to pair with Incident Data Recorders (IDR, or “black box”) to aid crash investigations. When the data recorder is tripped by a crash impact, the camera will also engage, capturing footage of the driver’s movement in the accident and providing another reference point for competition officials.

“This is going to be a very, very powerful tool,” Stefanyshyn says, indicating that the system is projected to be in place a third of the way through the season. “We have about 10 years of incident data recording. We have a very robust database that we use to continue to learn and improve. This will just be the next installment of analytical capability, which will allow us to be very precise and move very quickly.”

Changes are also in store for the NASCAR Xfinity Series, which will enter a transitional year for the new flange-fit composite bodies ahead of a full 2019 rollout. The series will also make improvements in the area of superspeedway bump-drafting, using a lower front fascia at Daytona and Talladega. The goal of mismatched front and rear bumper heights is to deter teams from locking on in the aerodynamic draft, a practice that’s currently officiated from race control.

The Xfinity tour will also expand the use of the aerodynamic package that debuted last year at Indianapolis Motor Speedway to largely positive reviews. That package — which utilized a taller rear spoiler, a restrictor plate and aero ducts to reduce the advantage of a leading car in ‘clean’ air — will also be used at Pocono Raceway and Michigan International Speedway this season.

For the Camping World Truck Series, the most impactful change is under the hood with the introduction of the optional NT1 engine. The Ilmor-produced powerplant, Stefanyshyn says, is intended to reduce engine development costs in the sport’s entry-level national series.

Other highlights of the 2018 NASCAR national series rules update, with some moves previously announced:

• NASCAR will reduce the number of over-the-wall crew members from six to five for pit stops. The move will push teams to find new, creative ways to execute pit service.

• NASCAR will move to a standardized team roster for at-track personnel, helping to more clearly define the roles of teams’ support staff.

• A new inspection station, developed in conjunction with Hawk-Eye innovations, will provide more comprehensive scans of vehicle bodies. The system will replace the former Laser Inspection System and several measurements previously done by templates.

• Common pit guns will be in use for the 2018 season, in an effort to reduce the performance premium on equipment and place the emphasis on the pit crews’ athletic performance.

• A new system for enforcing practice time penalties will be in effect for 2018. Instead of having car and driver sit idle on pit road, practice-time deductions will be enforced by covering the car in the garage. Practice holds will also be enforced at the end of practice sessions instead of the beginning.

NASCAR pit crews received the equivalent of a summer reading list shortly after school let out last November at Homestead-Miami Speedway. That primary offseason assignment: Adjust to new rules that reduce the over-the-wall crew from six people to five.

The move has pushed teams to tap into their collective creativity in the offseason, devising and practicing new choreography for quickly swapping four tires and adding fuel. But NASCAR’s competition department has had to make its own adjustments, learning from the teams’ feedback to clarify the guidelines for the new world order in pit service.

“We’re always throwing ideas back and forth,” says Scott Miller, NASCAR Senior Vice President of Competition. “A lot of the things we ultimately come up with as the final rules were not done by us in a vacuum, but done with lots of input from the people that it affects most.”

MORE R&D: Explaining inspection process | 2018 rules updates revealed 

Those regulations for pit crews and other team personnel were among the items unpacked Thursday at the NASCAR Research & Development Center in Concord, North Carolina, during what’s become an annual media briefing of the 2018 rules update. The related topic of standardized team rosters also was on the discussion docket, with at-track personnel numbers in place starting later this month at Daytona International Speedway.

The primary goals of the pit crew reduction were not only to reduce the number of team members on pit lane for safety reasons, but also to highlight the sports performance of over-the-wall crew members, some of whom will now be adapting to double-duty during stops.

“Not that there wasn’t a strong emphasis on the athlete in the old system, but we believe this even puts more emphasis on it,” Miller says. “One of the things that we’re really looking forward to is we’ve given them in the rules some flexibility with how they can use the men that are over the wall. So I think it’s going to be interesting to see how the teams develop the concept and who comes up with the best way to skin the cat, so to speak. We expect to see some varied strategies on that, which I think will be a very interesting story in the coming year.”

MORE: NASCAR to standardize rosters | FAQ on roster moves

Tire carrying, tire changing and jacking up the car will now be handled by a group of four. One member of that quartet who performs double-duty will be allowed to stand on the ‘hot’ side of the pit wall, springing into action once the approaching car is one full pit box away from their stall. That move is intended to keep crew members from jumping off the top of the pit wall with both hands full, especially with a heavy tire.

A fifth person will serve as the fueler, who is prohibited from any other pit-stop duties. A light-duty extra person will be allowed over the wall only as a driver assist, with such responsibilities as providing food or drink to the driver and changing windshield tear-offs.

Pit-road officiating with a camera-based replay system went into effect before the 2015 season. This year, more monitoring will be in place to govern the use of standardized pit guns. Starting this year, NASCAR will issue standardized air wrenches, air hoses, regulators and control boxes to teams at each event, re-collecting them at the end of a race weekend.

The pit guns, made by Italian manufacturer Paoli, will feature a parity monitoring system to detect and deter any tampering. Competition officials indicated a similar system will eventually monitor and officiate lug-nut tightness, once the procedure passes through beta testing.

“That kind of goes along with the crew, back to emphasis on the athlete rather than emphasis on the equipment,” Miller says. “I think the athletes are certainly part of the show and part of the story, and the more emphasis that we can put on their performance as opposed to a fast jack or a fast pit gun, the better the level playing field and the better stories we have to tell.”

As announced last November, organizations will also need to comply with standardized sizes of at-track personnel once the season begins. The rules now delineate organizational staff (such as tech director, competition manager), road crew (engineers, crew/car chief, spotters) and pit crew.

RELATED: Teams in development mode with new pit-stop rules

Monster Energy NASCAR Cup Series teams will be allotted 12 road crew slots and five pit crew positions per vehicle. Three organizational staff will be allowed for one- or two-car teams; an additional organizational member will be permitted for larger teams. Positions such as team owners, public relations staff and the hauler driver are exempt from the cap.

“Several goals, but one of them is to just standardize the size of the team that’s at the race track. There was a lot of different things going on and we’re always trying to create a level playing field in every aspect of our sport, and I think just another element of that was … football teams have X amount of people on them and baseball teams have X amounts of people on them and now race teams have a defined number of team members.”

The new rules also allow for cross-over duties within an organization, such as a member of Hendrick Motorsports’ No. 24 team helping on the Hendrick No. 9 team. Roster spots can be shared outside of an organization — for instance, a Joe Gibbs Racing road crew member assisting with Furniture Row Racing, an allied team — but the crew member must be listed on both rosters.

Enforcement will be assisted by RFID chips embedded in credentials to monitor teams’ roster attendance. A roster cap infraction would result in the ejection of the offending individual from a race weekend, plus at least one other rostered crew member’s removal, to be chosen at NASCAR’s discretion.

NASCAR officials will also have visual cues regarding their proper roles, with crew members wearing two patches — one identifying their car number and a second, with an abbreviation denoting their duties. The patches will be affixed with Velcro, so that the car numbers and abbreviations can be switched when a crew member transfers to a different team or role.

“Ultimately, the fans will learn those designations and be able to relate to those crew members as say, the underneath guy on my favorite car,” Miller says. “… I think it will start to put faces to the people behind the scenes supporting the drivers, which I think ultimately will be a good thing for the sport.”