Thermal expansion of steel is .0000072" per degree F. All you would need is a 100 degree F temp change to blow that tolerance out of the water. And 100 degrees is not that much when it comes to cars. A freezing cold day versus a boiling hot day in the summer is a temperature swing more than 100 degrees. A ICE engine runs at roughly 250 degrees F so that right there would easily expand parts way more than the tolerance he is calling for. On an EV, I don’t think anything gets that hot, but the motors still get warm.