Weakened US fuel-efficiency rules and promises of cheaper cars could see drivers pay higher running costs while also increasing carbon emissions.

As part of its "Freedom Means More Affordable Cars" initiative, the US Department of Transportation this week rolled back fuel efficiency rules under the guise of lowering vehicle prices. The Trump administration's transport agency says US taxpayers will save $138 billion (€122 billion) over the next five years — new vehicles will be $1,300 cheaper on average — since automakers will no longer have to invest in more fuel-efficient fleets. But this does not account for soaring gas prices as Middle East conflicts choke global supply.