[chrisseaton]

Is it really a 4x difference? And don’t British people drive more shorter trips than the US so even if that’s the case it’s also the wrong way around?

[aronpye]

Fuel and oil quality is a lot more variable in the US as it’s set at the state level, plus it’s just generally worse, so are the environmental conditions, so you have to set the guidelines according to the minimum / worst case likely to be encountered.