WELL DONE, some good info there.
Could it be because of the new injector/fuel pump/spark plugs that they use now as opposed to the ones the originals used as all of these have been upgraded now, and the letter change suggests that its standard on the new versions.
or
Has it changed because the piston rings used are different...............even the pistons themselves as rumour has it.
Think a further email is necessary.
cheers mate, im intrigued now by the difference in hardware. has to be major to justify a different engine code which would make the rumours true about pistons.