Republicans are making fun of Sen. Barack Obama’s (D-Ill.) suggestion that keeping car tires inflated is a key to solving the country’s energy crisis, and now GOP presidential candidate Sen. John McCain is trying to raise money off the issue.

In a fundraising e-mail sent to supporters, McCain (Ariz.) campaign manager Rick Davis offered to send an “Obama Energy Policy” tire gauge to any contributor who donates $25 to the McCain campaign in an effort to put Obama’s suggestion “to the test.”

The McCain campaign has continued to stay on the offensive over the past week, criticizing Obama for his opposition to offshore drilling.

The Illinois Democrat on Monday gave a speech in Michigan that detailed his energy plan, and his campaign noted in an e-mail that McCain supporters California Gov. Arnold Schwarzenegger (R) and Florida Gov. Charlie Crist (R) have made the argument that inflating tires can help and that NASCAR officials have said the same.

Obama said over the weekend that he is open to a compromise on offshore drilling legislation providing it works in tandem with other energy solutions.

In an internal campaign e-mail containing talking points for surrogates, the Obama campaign said the Illinois senator has never been opposed to offshore drilling.

“Sen. Obama has never been opposed to increasing domestic drilling,” the e-mail reads. “He merely opposed giving the oil companies more areas to drill, while they are currently NOT drilling in 68 million acres that are open to oil exploration. If we opened up those 68 million untapped acres, we would double our domestic oil production and boost our natural gas production by 75 percent.”

Obama also launched a television ad Monday, accusing McCain of being in the pockets of oil companies, comparing him to President Bush and saying the Arizona senator has received more than $2 million in campaign donations from oil companies.

In his speech Monday, Obama said the federal government should tap the Strategic Petroleum Reserve to provide instant relief at the pump, a plan Bush and Republicans have steadfastly denounced.

McCain spokesman Tucker Bounds said Monday that tapping the reserve “is not a substitute for a real plan to increase supply through additional drilling and nuclear power.”

“The strategic oil reserve exists for America's national security strategy — not Barack Obama’s election strategy,” Bounds said in a statement. “The last release of oil from the strategic reserve came in response to Hurricane Katrina, but the only crisis that has developed since Barack Obama last rejected this idea two months ago is a slide in his poll numbers.”