I did a trial run a fortnight ago fom Pembrokeshire Wales to Hereford to pick up my co driver then up to the lake district and back to Hereford and home in my MK3 Triumph Spitfire 1300 with overdrive main roads averaging 55mph motor way 60 to 65mph and was averaging 44mpg which did surprise me. driving localy 32mpg.The rebuilt engine has certainly had a good work out 700 miles in two days and good prep for the RBRR