Report UK sets out a plan to become the world leader in electric vehicles in House prices and the economy Posted July 12, 2018 22 hours ago, Tes Tickle said: They always work, even when cold. They trap 100% of the soot all the time. They only fail to regenerate if they don't get hot. That gives the owner a bill for cleaning or replacing it, it doesn't affect pollution (well, other than in making a new one). They've got much better over the years though - most now use a fuel additive that greatly reduces the flashpoint of the soot. Spot on.