I am looking to buy a Spitfire to do long cruises. I had thought to get one with OD because of the extra gear leading to less revs when cruising and a saving in mpg. From what have found out OD changes top from 1:1 to 1:0.8, and possibly mpg from 30 to 35. In these forums it is suggested that having OD adds £1000 to £1500 to the price. If I do about 10,000 miles p.a. and the above figures are roughly right that would be 3-5 years to get the outlay back. There are also a lot of threads here about problems with the overdrive. So, is it worth it, the extra money, the possible failure? Any advice would be very welcome as I am new to Spitfires and the last time I used an OD was in the 70's, in a Dolomite I think.
