Hi,
I have an 8v (4T) box in my 16v Mk2 and fuel economy is excellent!!!! I can get 450 miles to a tank when cruising on motorway, because at 70mph it does around 3k rpm, at100mph

the car is still only at 4k. Oh, and you can imagine what speed i was doing when i was at 6k!!! BUT, there is a definite compromise in acceleration as my housemate who also has a 16v will p#ss all over me from 0-60. It is worth it for fuel economy purposes but sometimes i wish i had a little quicker acceleration provided by the 2Y box.. Also due to the extra long 5th, acceleration at around 70mph isnt that great as you are only doing around 3k, and as you all know they pull between 4.5-6.5k, whereas if you have the 2Y 16v box acceleration at this speed is a lot better as you are already in the power band. but hey.....i save money so who cares!!! Though, they valvers are still quicker than most things on the road anyway

haha