Which 3.5-tonne panel van, new or old (preferred), has the greatest payload? The van will have to carry a lot of weight occasionally, so front-wheel drive would be more convenient, but would a bigger engine be better than a smaller engine in terms of fuel economy, as the engine is less stressed? The Renault Master/Vauxhall Movano is looking like the best so far. Overall running costs are also an important factor. It will be used as a mobile workshop for agricultural purposes.