It sounds like the type of driving you do is in sync with the strengths of diesel engines. The Octavia Scout is a favourite of ambulance paramedic first responders, with its car-like driving characteristics and practicality, as well as a good degree of off-road capability. Company car tax rates are set for the next few years, with annual incremental increases for all fuel types. Potential extra levies on diesels could only come from local congestion charges or parking prices. Really you have to choose the car best suited to the type of driving you do for work, and the Octavia Scout, or cars with similar characteristics, would seem to do the job well enough. Switching to a different fuel type, such as petrol or a plug-in hybrid, could end up costing more on fuel for private mileage and BIK tax.