Nothing strange about that - if there is a limit  that is hard to meet (which there should be) then manufacturers will make a car that <i>exactly</i> meets the standard.<p>And just like advertised fuel consumption figures, it will meet the standard under very controlled circumstances. In case of fuel consumption the manufacturers can reach the figure by taping shut door seams, using overinflated tyres, throwing out interior to reduce weight etc. Those aren&#x27;t &quot;real world conditions&quot; but apparently they are real-world enough to use in advertising. Presumably the same conditions can and are used when testing emissions.<p>The only conclusion we can draw is that emissions tests aren&#x27;t used to make manufacturers build cars that emit at most X in real world conditions. That would be both unfair and expensive - it&#x27;s <i>better</i> to say &quot;use whatever extreme conditions you want and the emissions should be at most Y&quot;.<p>In that case authorities can make Y &lt; X and the whole thing is simpler and easier for everyone. If cars emit too much in real-world conditions? Then tighten the limits.<p>This of course only works so long as no one cheats and designs workarounds <i>specifically</i> for the test conditions (which is what VW did).