I would be interested in finding a Custom Gearbox to fit my car, if there is one made, that would decrease the revs in 5th when doing 70, the main reason for this would be to save on fuel as I do a lot of motorway driving.

I don't think there would be any need to change the other gear ratios, although I hardly every use forth, so I guess that could be moved to the ratio that used to be used for 5th (or somewhere between what is currently 4th and 5th.

Anyone done this previously, and if so, how much did it cost?

I have a Octavia 1.9TDI 2001 110BHP model.

Any ideas on this would be greatly appreciated.

now I would like to know this too.

I want a 6 speed box. The same 5 in there now and another a tad higher just to get the revs from 3k ant 75-80mph down to 2.5k-2.6k ish

not sure what the 6 speed diesel box is like but iirc they say a petrol car needs 300bhp to take advantage of it.

billy

i would say the 6 speed box does need a lot of power i have plenty of bhp and 6th is about as much use as a choc fire guard, but on the other hand it could be that i need a lot of revs to get going.

I wonder if the 6 speed diesel box that is designed for the Octavia II would fit. I would also be interested to know how all the gears within it compare to the 5 speed I currently have.

mmm not sure if the mk 2 will fit mate. mind cant see there bein a diff between the 5 n 6 speed diesel box neither. bit like the 5 n 6 box for the petrol.????