IndyCar '06 had its share of ups and downs

The memories are getting a bit dim because the season ended three months ago, but the IRL IndyCar Series staged one of the finest championship battles in open-wheel history in 2006. Sam Hornish Jr. ultimately prevailed from a four-man duel that pitted two of America's best open-wheel teams in 14 rounds of direct competition.

If the tense championship battle that came down to the very last lap of the final race highlighted the IRL's 2006 campaign, the lack of consistent competition for juggernauts Penske Racing and Ganassi Racing stood out as the lowlight. The move to a spec Honda engine was intended to level the IndyCar Series' playing field, yet all it did was magnify the advantages that the Penske and Ganassi teams engineered into their cars within the limited scope of the IRL rule book.

With those season-defining themes in mind, let's look back at the individual highs and lows of the 2006 IRL season.

HIGH: Dan Wheldon justified his exodus from Andretti Green Racing by winning in his Ganassi Racing debut at Homestead-Miami Speedway. And he did it in style, driving around Helio Castroneves in the final corner.

LOW: Paul Dana of Rahal Letterman Racing was killed in an accident during the Homestead race-day warmup practice session when he appeared to ignore caution flags, raising questions about the rookie driver's inexperience.

HIGH: Castroneves ended eight years of frustration spanning his CART and IRL career by winning in commanding fashion at Twin Ring Motegi, Japan.

LOW: There was not an Indy-style open-wheel race at Phoenix International Raceway for the first time in more than 40 years.

HIGH: The entire month of May passed without a major engine failure in more than 30,000 miles of running -- a tribute to Robert Clarke and his associates at Honda Performance Development.

LOW: Once again, car count for the month of May was a serious issue. The Indianapolis 500 barely was able to again attract a field of 33 cars and Bump Day featured no bumping.

HIGH: Hornish recovered from a late-race pit incident with a sensational pass of rookie Marco Andretti in the last-lap sprint to the finish of the Indianapolis 500.

LOW: Eddie Cheever got together with rookie Andretti on-track in the wet Watkins Glen race and engaged in a war of words in the press with the Andretti family.

HIGH: There were no crashes in the race at Texas Motor Speedway, normally a tense, nail-biting affair.

LOW: Harder Firestone tires and the IRL's class system (Penske and Ganassi vs. the rest of the field) meant the Texas race had little of the wheel-to-wheel racing that normally makes it a tense, nail-biting affair.

HIGH: Hornish took the championship lead after winning at Richmond and Kansas.

LOW: He gave it right back up by crashing at Nashville.

HIGH: After acquiring a Dallara chassis like everyone else, Danica Patrick's 2006 season finally kicked into gear with a fourth-place finish at Nashville. She repeated the result in the next race at Milwaukee.

LOW: After the start at Michigan International Speedway was delayed by rain, Hornish lost a fuel pump and Scott Dixon ran out of fuel, helping Castroneves win the most boring race of the season.

HIGH: Patrick made a fool of herself (but produced some great "SportsCenter" highlights) with her churlish display of disappointment after running out of fuel at Michigan.

LOW: Wheldon saw victory slip away for at least the third time of the season, this time when he overshot his pit for the final stop at Kentucky.

HIGH: Andretti claimed his first IndyCar Series race win on the Infineon Raceway road course.

LOW: Andretti needed a full-course caution to stretch his fuel to the finish at Infineon Raceway, and lo and behold, his normally reliable Andretti Green teammate Bryan Herta spun and stalled.

HIGH: Once Castroneves recovered from an early mistake, the four championship contenders staged a thrilling race in the Chicagoland Speedway finale.

LOW: The Ganassi and Penske cars were so superior, they lapped the field at Chicagoland.

HIGH: Indy-style cars ran at Daytona International Speedway (albeit in testing on the road course) for the first time since 1959.

LOW: Hornish fared poorly in two late-season NASCAR Busch Series starts for Penske South, but he still appears destined to be the next top-line open-wheel star to defect to the stock-car world.

John Oreovicz covers open-wheel racing for National Speed Sport News and ESPN.com.