the 56 onwards one is a 1.4 n/a,the cooper is a 1.6 variation of the 1.4 engine,which is used in the mini and peugeot 207 and the cooper S is a 1.6 turbo lump which is the same as the peugeot 207 gti ,the diesel engine is the same as the citreon c2 and another small peugeot the old new mini was 90bhp 1.6 from the chrysler engine which was based on the dodge neon engine,the cooper was the same engine but with a different ecu map(bmw can actually change the map on a one to have the sam epower as a cooper and the cooper S was a 1.6 supercharged engine wiht aobut 163bhp,the clubman uses the same engines as the other new mini's and is called a clubman because bmw group dont own the copyright to the traveller name used by austin rover