Sunday is a gearhead’s dream — the Indianapolis 500 followed by the Coca-Cola 600.

The most prestigious open wheel event in the world begins at noon while the longest race in NASCAR starts just over five hours later.

And this year television moguls are keeping a close eye on how many people watch the races because this is supposed to be the comeback year for the Indy Racing League.

Now that open wheel competition is unified again, thanks to the demise of the Champ Car Series — and since Danica Patrick created some much-needed buzz by winning a race — there are those who think stock car racing might have some competition again.

Back when NASCAR was still a regional sport its Memorial Day race couldn’t hold a candle to the Indy 500. It’s all you heard about on TV and read about in the papers, and from a national standpoint Charlotte’s little ol’ race was an afterthought.

It was competition with the events at the Brickyard that led to the gimmick of a 600-mile race. I guess, at the time, NASCAR thought if it couldn’t be better, it could be bigger.

But these days, it’s both bigger and better. Now it’s the IRL that is trying to grab some of the NASCAR TV audience.

If the two races started at the same time, I’m guessing the Coca-Cola 600 would win the ratings war handily.

And that’s as it should be.

While the Indy 500 still has a certain allure — and certainly Patrick’s looks are a draw (it might sound sexist but it’s true) — open wheel competition has long been surpassed by the stock car brand.

NASCAR has the best drivers in the world, which is why guys like Juan Pablo Montoya and Dario Franchitti left lucrative careers in Formula One and IRL, respectively, to drive in the series. In fact, three former Indy 500 winners are in the 600 field.

It is also the more marketable of the two leagues. Twenty-five years ago, NASCAR’s top competitors could wander through the streets of any major city in complete anonymity. Now they’re megastars.

Today it’s the top open wheel pilots who can move freely throughout the country without being recognized, with Patrick, of course, the notable exception.

So Sunday, the IRL will use the Indy 500 as a gauge of whether or not it can once again compete with NASCAR. It will never overtake it — that ship sailed a long time ago when fans realized they could relate better to machines that looked like cars instead of wingless airplanes. But with the series no longer fractured, perhaps it can become relevant to the American sports fan again.

Meantime, the NASCAR Sprint Cup Series will keep chugging right along, secure in the knowledge that its “fight” with the IRL has already been won.

Fortunately this is a big country. Just as NASCAR has room for superspeedways and road courses, I’m guessing fans have room for two entirely different brands of racing.

So ice down the cooler, break out the snacks and find a comfortable spot in front of the TV Sunday. If you’re a fan of motorsports, the Indy 500 and the Coca-Cola 600 will offer the best of both worlds.

And you won’t have to choose one over the other.