It's the pressure, stupid! Rivals trade blows over tyres

The runners in the race for the White House have discovered a new instrument for needling one another in the silly-season that is August: a tyre-pressure gauge.

What has mostly been an earnest debate this week about future energy policy was still being partly overshadowed by a tyre-tread tit-for-tat that started when Republicans poked fun at Barack Obama for saying that maintaining proper pressure will help to reduce reliance on foreign oil.

Campaigning yesterday in Lima, Ohio, a bellwether state in US elections, Mr McCain told a large crowd that Mr Obama "is claiming that putting air in your tyres is the equivalent of new offshore drilling," raising modest ripples of laughter. "That's not an energy plan my friends. That's a public service announcement."

He made similar remarks to a rally of motorcycle enthusiasts in South Dakota earlier this week, but then seemed to back off, conceding "we should inflate our tyres" to save fuel consumption. That in turn spurred Mr Obama, campaigning in neighbouring Indiana to accuse Mr McCain of a rubber flip-flop. "It will be interesting to watch this debate between John McCain and John McCain," he remarked tartly.

The back and forth was fuelled in part by the Republican National Party which began distributing free tyre gauges to reporters with "Obama Energy Plan" emblazoned on their sides. But Mr McCain was also trying here in Lima to refocus his message, in particular his increasingly vocal pitch for America to expand its oil-drilling commitments. "We need to drill here and drill now!" He also underscored resurgent themes of his stump appearances: that he is the underdog and the maverick.

"On election night we might be up late. And, my friends, we are the underdog," he told his town hall meeting in central Lima. "I need your help because we can win in November if we can carry Ohio."

If Team McCain was facing distractions, they were largely of its own making. This week they have included not just the duelling on tyres but also the continuing fall-out from Mr McCain's television spot of a week ago calling Mr Obama a celebrity and featuring Paris Hilton, who this week struck back with her YouTube video making fun of the "wrinkly white-haired dude".

Mr Obama, meanwhile, will largely leave the campaign stage to his opponent as he leaves this evening for Hawaii where he will be on holiday with his family for a week. "The world's biggest celebrity will be off the campaign trail, so we figure we'll have a better opportunity to get some attention on the campaign trail all by our lonesome," a McCain spokesman, Tucker Bounds, said. "Next week will be about John McCain reaching out to voters."

Latest polls still seem to show a largely static race. A new Time magazine poll put Mr Obama at 46 per cent compared to 41 per cent for his rival. While not bad news, these and other polls show Mr Obama still not breaking free from his rival nor through the 50 per cent mark as many in the Democratic Party think he should have done by now.

On his return from holiday, Mr Obama will be two weeks from his party's convention. Before then he has to choose a running mate and heal lingering divisions with Hillary Clinton. Last night, the offices of Mr Obama and Mrs Clinton jointly insisted that they were working well together.

* A man said by US authorities to have had weapons and military-style gear in his hotel room appeared in court in Miami yesterday on charges that he threatened to assassinate Barack Obama. Raymond Hunter Geisel, 22, was arrested on Saturday.

So, who's right?

Low tyre pressure means more rubber comes into contact with the road. This increases the force of resistance between tyre and road, so more fuel is needed to keep the same speed as with firmer tyres. And from a green perspective, this also increases CO2 emissions. In US Department of Energy advice, drivers are told to keep tyres "properly inflated and aligned to improve your gas mileage by around 3.3 per cent".