Ok so I can't do single cylinder deactivation very easily, fair enough.
Maybe something to look into when I do my own engine management... I guess this is the reason why VW's system closes off the intake and exhaust ports? Never really understood that before.
I'll see about fitting a vacuum guage then

I don't mind doing that as the rest of the stuff I'm doing is enough work anyway.
Has anybody attempted to make an automatic pulse and glide system yet? Like a very advanced cruise control aimed specifically at fuel efficiency.