Car Comparator | Cars | Honda (UK) This is an interesting page. Pop in your model Accord and then the equivalent diesel version, set the years and mileage. You'll see there is very little in it pence per mile. The higher petrol fuel cost and road tax is offset by the diesel model costing more to buy, service, but less to tax and fuel. Quite an eye opener, well done Honda. Thats before you factor in the potential for expensive repairs on a diesel if it all goes 'pete tong'.