NASCAR has announced revisions to the Sprint Cup Series rules and regulations for the 2015 season, with a complete ban on private team testing top of the changes.

As of next year, teams will only be allowed to participate in official NASCAR and Goodyear tests. There will be harsh punishments for any organisation found in breach of this rule, which would incur a level six penalty on NASCAR's tiered level of evaluating the severity of infractions, which would mean a loss of 150 points, a minimum $150,000 fine and a six-week suspension for the crew chief and other crew members involved.

Until now, teams have been allowed to test at non-sanctioned facilities as often as they choose in addition to a minimum number of tests allowed at tracks that host Sprint Cup Series races as well as a three-day pre-season test at Daytona International Speedway. NASCAR had previously felt that monitoring testing across the country would not be practical, but has now been convinced that it is both possible and desirable to do so as it will help teams control spiralling development and running costs.

"What we're trying to do is get Goodyear, NASCAR and team testing, which are separate now, and bring all three of us together," explained Gene Stefanyshyn, NASCAR senior vice president of innovation and racing development.

"If we organise it well and do it in a smart way, say 'Goodyear's got to do their stuff, let's help them; NASCAR and the teams, if we want to look at this low downforce world, let's work together; and then you teams, you've got your time,'" he added. "That's the thinking, but we have to figure all that out."

"In one respect it's great," responded reigning Cup champion Jimmie Johnson on Wednesday. "We don't have to spend more time away from home [in order to] go testing. As long as you're in great shape, you're going to be happy with that rule."

"We're going to have to do it the old fashioned way, at the track [during race weekends]," he added. "Use practice sessions as test sessions and also fall back on our tools and instruments that we have in-house at Hendrick Motorsports."

"The testing ban is the right decision," agreed Michael Waltrip Racing's Brian Vickers. "It saves car owners some money and increases the quality of life for all the crew that don't get to spend a lot of time with their family."

Other changes announced this week include shortening the rear spoiler from 7.25 inches high to 6 inches; a decrease in aerodynamic downforce by about 300 pounds; tapered spacers to reduce engine horsepower from 850 to 725, which will slow cars from between 3-6mph; lower rear differential gear ratios targeting 9000rpm from 9500rpm currently; a drop in the minimum vehicle weight by 50lbs via a reduction in ballast; a rear spoiler adjustment from 8 to 6 inches high; and an optional driver adjustable track bar. Restrictor plates will remain at superspeedway races at Daytona and Talladega.

"The combination of a lower horsepower package, and a new aero package, which takes about 300 counts of downforce off of the car, we believe will make for an even better racing product," said NASCAR's executive vice president and chief racing development officer Steve O'Donnell. "I think where you will really see it is in the turns, where drivers need to come off the throttle more, and we believe that will be where we see more passing, in turns."

In addition to engineering changes, NASCAR has also said that all events in 2015 will now use the elimination round qualifying format introduced this year, including the Daytona 500 which was exempted from the change in 2014. However, while the front row at Daytona will now be set through group qualifying instead of the traditional single-car runs, the rest of the field will continue to be set by a pair of qualifying races later in the week before the race.

There will be some changes to the qualifying format for 2015: the first segment on short tracks and intermediate tracks will be reduced to 15 minutes, then 10 minutes for the second and a final 5-minute top-12 pole shoot-out session. At superspeedways, the field will be divided into two groups for the first 5-minute session, followed by two more 5-minute sessions while road course qualifying will see a 25-minute initial session followed by a 10-minute pole decider.

And in a watershed moment for the Sprint Cup Series, NASCAR has said that Goodyear will be introducing wet weather tyres for use in the two annual road course races at Sonoma and Watkins Glen, meaning that the series could see its first-ever wet weather events. It's a move that mirrors the situation already in place in the Nationwide and Camping World Truck Series championships.

"The fans obviously love it," said O'Donnell. "If it's a complete downpour, obviously we can't race. But Goodyear is able to build a tyre for Cup, and we talked to the teams and they said, 'Let's do it.'"

NASCAR summed up the new rules package by saying that the aim was enriched competition, improved safety, reduced costs, enhanced product relevance and environmental/green improvements, with fans benefiting from closer racing and more passing opportunities in races that have recently been increasingly ruled by aerodynamic packages.

"We have had fantastic racing so far in 2014," said Stefanyshyn. "We remain committed to constantly looking to improve it. Our fans deserve it and our industry is pushing for it. That will not stop with the 2015 package; the development will continue over many years to come."

"This race package represents a lot of hard work by NASCAR, the race teams, the drivers, our manufacturer partners and Goodyear," Stefanyshyn added. "We've remained committed to constantly looking at our racing, and the work that has been done has been aimed at getting a rules package delivered to the race teams as early as possible."

"We're very pleased with the rules package and what it will do for our racing," summed up O'Donnell. "We're confident it will continue to generate great racing, along with continuous safety improvements.

"We've had great dialogue with our drivers and teams, our manufacturers and Goodyear, allowing us to build greater efficiencies into the 2015 rules package," he added. "We've met our goal of delivering rules to teams with time to prepare for next season and we're seeing the benefits of an updated process for developing our rules paying dividends. It will only continue to improve."

Jimmie Johnson broadly welcomed the new rules announced this week. "I was in a great conversation with [Clint] Bowyer," he said. "He brought up a good point. Every time there is change, there is more competition. When the rules sit still for a long period of time, [competitiveness] kind of falls into a follow-the-leader type of event. With more change, there will be that race again to find out who can figure out the mousetrap first.

"I'm not against that. And at the end of the day, if the cars really have a lot of give-up in them and they are abusing tires and wearing tyres out, that's going to create the best racing for us."