Hi David In the early Road Test Articles the fuel consumption graphs are given. Mk1 Manual MPG Speed Direct Overdrive 30 29.8 36.0 40 30.5 34.8 50 28.8 33.3 60 25.8 29.4 Autos are the same as Direct This comes from the book Triumph Stag 1970--1980 published by Brooklands Books Peter Howells