anyone know what model of mk3/4 or even 5 escort had the highest ratio gearbox ?

or are they all the same ?

my TDI estate has plenty of torque but not enough revs so is revving quite high at motorway speeds

 

The actual gear ratios are the same for the Series 1 and Series 2 gearboxes, the only gear difference is the final drive ratio.
The Series 1 RST had a 4.0:1 final drive and the Series 2 had a 3.8:1 final drive ratio, this is what makes the Series 1 feel better on acceleration and gives the Series 2 better top end speed.

 

cheers , any idea what 5th gear ratio is on the diesel mk5 box ?

or any idea which has the highest 5th out of all the boxes not just the RS's ?

 

To be honest no, but if you give a search in the forums you will surely get the answer. I know that info cause I recently spoke to one of Bernie's guys for my box

 

All the same I believe.

1.6 Diesel Fiesta (1984-86) has the highest overall gear ratio of 3.33:1