From Nascar.com A further reduction of downforce and the implementation of additional safety developments highlight the 2017 NASCAR premier series rules package announced by sanctioning body officials on Friday at Kansas Speedway. Aerodynamic adjustments similar to those in place for races at Kentucky Speedwayand Michigan International Speedway in 2016 form the framework for the 2017 performance platform. However, slight modifications to the overall base package have been made. According to officials, the 2017 race package will include: • Rear spoiler dimensions for all non-restricted events will be 2 3/8 inches x 61 inches. Current spoiler dimensions are 3 1/2 x 61; for the Kentucky and Michigan races, the dimensions were 2 1/2 x 53 inches. • Splitter measurements for the 2017 package will be the same as those for the 2016 Kentucky and Michigan races, with a 3-inch reduction in the outboard (side) areas; • A tapered rear deck fin; • Net rear steer setting of zero. The aero changes are the next evolution of the platform first rolled out for select events in 2015. Mandatory for 2016, those changes reduced downforce (the pressure exerted on a vehicle as it moves through the air) from 2,700 pounds to approximately 2,000 pounds. The 2017 package is expected to reduce downforce by approximately 500 pounds, landing in the 1,500-pound range. "The objective there is to give the drivers, put the driving back in their hands a bit more … take less aero dependence off the car," Gene Stefanyshyn, NASCAR Senior Vice President of Innovation and Racing Development, told NASCAR.com. "That's the big thing. "The amount we are taking off the front and the rear is the same proportion; we try to keep the balance of the car identical. So it's been taken off in the same proportion to maintain the balance of the car as it was last year." Safety enhancements, which include strengthening the interior driver compartment, will be mandatory for superspeedway events at Daytona International Speedway and Talladega Superspeedway and optional at the remaining venues for 2017. Officials previously announced thicker anti-intrusion plating where it already existed in the cockpit as well as additional plating in areas not currently covered. Toeboard foam will also be mandatory at superspeedways, as will the addition of a roof hatch. Changes to steering column mounting and the use of a garage-only fuel coupler (mandatory for all events) complete changes in the safety arena. "Basically … there is going to be a strengthened dash firewall; (on the) front left of the chassis there will be a piece zippered in; also in the back, near the rear clip, another piece that will be zippered in," Stefanyshyn told NASCAR.com. "The floorboard and toe board area will be made out of one piece, beefed up, also. "This has a couple of elements to it; one is to manage front crash, the other to manage if you are hit in the side." A stronger floorboard, with toe board foam, should lessen the odds of a driver involved in a hard impact suffering a broken limb. The fuel coupler designated for garage use only is intended to lessen spillage by more efficiently closing the valve upon disengagement. It is a safety as well as environmental initiative. The aero package for superspeedway races at Daytona and Talladega will remain unchanged, although there will be a decrease in restrictor plate size (from 57/64ths to 7/8ths of an inch) to combat increasing speeds at the two tracks. Additionally, the vehicle weight will increase by 20 pounds to accommodate structural changes to the cars. NASCAR will also reduce the tire allotment provided to teams next season and require teams to start the race on the tires used in qualifying. "We've been tracking tires for two or three years now and we see how many are purchased and how many remain," Stefanyshyn said. "We are seeing that there is an opportunity to trim some tires. … Also we're starting to creep up to trying to bring some strategy around the tires. "It's not a huge reduction, it's a comfortable reduction but it's kind of moving in that direction." Officials said unveiling the potential packages in advance, as was done in '15 at Kentucky and Darlington, and again in '16 at Kentucky and Michigan, provides the opportunity for optimum feedback. But those tracks are not locked in a "test" venues. "We're always looking at different ways to do things … we would hope that next year's package can be a continuation and a little bit more of a long-term, stable rules package," Scott Miller, Senior Vice President of Competition for the sanctioning body, said. "But nothing ever stays the same. Moving forward we will look at more efficient ways to potentially test possible packages for the future. "I think we did a good job the last few times with the races, that's really the best way to collect data in an actual event … hopefully we can get out in front of it even a little bit further and get a little bit more of a cross section of race tracks if we have some proposed new things."