I averaged 48.23mpg over 11,341 miles in a 150PS SE-L Nav saloon auto on 3 Toyo tyres and 1 Michelin Primacy 3 (after a puncture). But I used only Shell V-Power Nitro Plus because that's what the engine is optimised to run on and in itself should give you an extra 3mpg or so, while the clean up effect should get you to more than 40. I did cruise at 73 on the speedo and a true 70 on the Tom Tom. Just 5mph more will affect the average economy by 3-5mpg. Long Term Test Reports: www.honestjohn.co.uk/our-cars/mazda-6-22d-se-l-nav.../ Real mpg: www.honestjohn.co.uk/realmpg/mazda/6-2013