The truth on the bus goes round and round...

When Piper Palin told a reporter and photographer in Philadelphia, "Thanks for ruining our family vacation," we could all sympathize, right?

Who hasn't had a few family vacation doozies.

But if the Palin clan wanted to travel incognito, one wonders if it was the best idea to travel in a bus emblazoned with the U.S. Constitution, Sarah Palin's signature, the address of a website to follow the tour and a "vacation" theme that sounds an awful lot like a campaign slogan.

Of course, when your mother is a former GOP vice presidential candidate weighing whether to enter the 2012 presidential campaign, maybe stealth is out of the question anyway.

Which brings us to Sarah Palin's exclusive on-the-bus interview with Fox News' Greta Van Susteren. Because what family vacation is complete without a political website weighing the accuracy of your mother's musings?

In the interview, Palin turned the conversation to energy policy and her opinion that there will be a steep price to pay for President Barack Obama's decision to place a temporary moratorium on new drilling in the Gulf of Mexico in the wake of the April 2010 Deepwater Horizon oil spill.

"The impacts of that moratorium, where 97 percent of our offshore has been locked up...what we're looking at now is 150,000 barrels per day less next year, and 200,000 barrels per day less being able to be developed from the gulf the year after because the moratorium disallowed the permitting process, disallowed rigs to be able to, economically speaking, stay in the gulf. They moved out," the former Alaska governor said.

"So we're going to be looking at $8 billion a day that we're going to be pouring into foreign countries in order to import that make-up fuel that we're going to need to take the place of what we could have gotten out of the gulf."

We broke this into two fact-checks.

In the first we checked Palin's numbers on the projected drop in oil production from the Gulf of Mexico, which she attributed to the moratorium.

We found Palin's numbers were a little high, but fairly close to the official projections from the government's Energy Information Administration, the federal agency that keeps track of energy statistics. According to the EIA's short-term energy outlook report from May 2011, crude oil production from the Gulf of Mexico is projected  to dip by 130,000 barrels a day this year; and another 190,000 barrels a day in 2012.

The bigger problem, however, is that Palin attributed the drop entirely to the moratorium.

In its May 10, 2011, report, the EIA says that was just one factor; that it was also "because of production declines from existing fields."

In fact, an EIA report from April 2010  -- before the oil spill -- projected oil production from the Gulf of Mexico would drop by 100,000 barrel a day between 2010 and 2011. After the moratorium, the projected drop went from 100,000 barrels to 130,000 barrels a day. Since most of the forecast decline predates the oil spill and the moratorium, it is misleading to attribute it entirely to the moratorium.  And so we rated Palin's claim Barely True.

We also took a look at the second part of Palin's claim, that "we're going to be looking at $8 billion a day that we're going to be pouring into foreign countries in order to import that make-up fuel that we're going to need to take the place of what we could have gotten out of the gulf."

We're not sure how Palin arrived at this figure -- and our attempt to get clarification from her political action committee was unsuccessful -- but some simple math showed her figure is indefensible. Using generous assumptions in Palin's favor,  we could only get to $34.6 million a day. So Palin's number of $8 billion a day is way, way off. We rated the claim Pants on Fire.

Also, we took a look at Palin's claim about the size of the debt accumulated under President Barack Obama.

"Look at the debt that has been accumulated in the last two years," Palin said.  "It's more debt under this president than all those other presidents combined."

Obama, along with Congress, has indeed accumulated a lot of debt for various reasons, but his two-year debt total -- even if you use the most generous standards for judging Palin’s comment -- is still $3 trillion to $7 trillion short of the amount needed to make Palin’s statement accurate. We rate her claim False.