Pressure is growing on van manufacturers to publish fuel economy and emissions figures of their models.
In a recent survey, 80% of fleet owners said manufacturers should make the figures publicly available.
Since January 1, van manufacturers must by law produce fuel economy figures and carbon dioxide emission figures for vans for the first time - but they don’t have to publish them.
Some van manufacturers are revealing the data, others are not.
Northgate Vehicle Hire managing director Phil Moorhouse said: “Fuel economy and CO2 data should be published by the van manufacturers and be available to all fleet operators.
“There are issues around both sets of figures being affected by whether vehicles are laden or unladen and their actual specification - factors that influence such data on commercials far more than in relation to cars.
“However, unless the vehicle manufacturers publish official data then more and more websites will spring up publishing their own figures that may or may not be accurate.