NASCAR At Kentucky: Quaker State 400 Viewer's Guide

Here are some things to watch for tonight's NASCAR Quaker State 400 at Kentucky Speedway:

Storylines

Rule changes

Kentucky represents the first race on a 1.5-mile track since NASCAR implemented rule changes to encourage more side-by-side racing (increasing ground clearance of the side skirts) and make it harder for drivers to get through the corners (limiting how teams can use rear sway bars to make the car turn better). Opinions on whether the rule changes will have the desired effect are mixed, especially when it comes to the sway bars, which is the more significant rule change of the two.

The team this could affect the most is Hendrick Motorsports, which have won five of the past seven races (including the All-Star Race) and a team that was using the loophole in the rulebook to their advantage. However, Jimmie Johnson and Dale Earnhardt Jr. both downplayed this, essentially saying they expect to be as competitive as they have been throughout the season.

Others, like Brad Keselowski called this a "game-changer" and expect the mandate on sway bars to dramatically alter and slow down the fleet of Hendrick cars. After 400 miles of racing tonight, we should have a better idea of who's right, who's wrong and who has to play catch-up to the rest of the field.

The heat

When the green flag flies tonight, temperatures are expected to hover right around 95 degrees and the track temp will be at least 15-20 degrees hotter. The heat, combined with a bumpy surface, will make tonight's race a challenge for drivers as the track will have little-to-no grip. If yesterday's first practice is any indication – Brad Keselowski, Juan Pablo Montoya and Marcos Ambrose all had issues within the first couple of minutes – expect drivers to have difficulty getting into and out of the corners.

And Jimmie Johnson made a good point Friday when he talked about how the heat affects the crew guys as much – if not more than the drivers – as the high temps easily wear everyone out and frequently leads to sloppy and slow pit stops.

Edwards and Busch need to go

Both Carl Edwards and Kyle Busch were expected to challenge for the championship, and while there is still time for things to change, neither looks anything remotely like a title contender.

Edwards has lacked speed, has just two top-five finishes on the year and would be out of the Chase if it started today. Busch is in the Chase thanks to his win earlier in the year at Richmond, but has finished 17th or worse in his last four starts due to three engine-related issues and an incident last week at Sonoma.

Both drivers need to pull out of their respective tail-spins, and Kentucky offers the perfect place for each to do so. Busch enters as the defending winner and Edwards has a knack for performing well on intermediate tracks and finished fifth in this race a year ago.

Worth Noting

• Dale Earnhardt Jr.'s 23rd-place finish last week at Sonoma was far and away his worst result of 2012. But despite the subpar finish, Earnhardt Jr. is still the only driver to have completed every lap this season.

• Surprisingly, this marks the first time since September 2010 at Dover that Jimmie Johnson was fastest in qualifying. On that day, the five-time champ led 191 of a possible 400 laps and easily drove to the victory. Seven of the last 11 times Johnson has qualified P1, he has gone on to score the win.

Favorites

1. Kyle Busch

Last year's Kentucky winner was fastest in opening practice and then backed it up by qualifying second. However, thanks to three engine failures in the last four weeks, there is one giant question mark hanging over Kyle Busch: Can his Toyota engine withstand high temps for 400 miles?

2. Jimmie Johnson

No driver has scored more points over the last six races than tonight's pole-sitter, who in that span has two victories and five top-five finishes.

3. Brad Keselowski

Brad Keselowski clocked in the 12th- and second-fastest times in Friday's two practice sessions. He did this despite having to go to a backup car just two minutes into opening practice. And he does have a history – albeit short – of doing well at Kentucky, as in last year's running of the Quaker State 400, the Penske driver led on three occasions for a total of 79 laps.