This is despite industry groups agreeing on the whole that fleets using fuel cards are able to manage payments, reduce fraud and monitor drivers' fuel habits more effectively.
The main advantage in the fuel card versus credit card debate centres on fuel management. By using a fuel card, fleets have access to information such as where fuel was bought, the time it was purchased, the quantity, the grade and the cost in pence per litre.
However, according to research completed by Datamonitor in its report 'Card Services for European Fleet Managers' last month, 20% of fleets are not sure of the services available from fuel cards (Fleet NewsNet, June 10).
Steve Riggens, marketing manager for fleet services at BP, outlined some of the benefits of using fuel cards over credit cards.
He said: 'Fleets can use online fuel account management services. This means managers can cancel or order new cards and manage their use online. If fleets are trying to manage miles per gallon across the fleet, they would be unable to do this using a credit card. The only details gained from a credit card are the place of purchase, price and time.'
Having greater control over fuel budgets enables fleets to become more cost-effective. Using a credit card system also enables drivers to purchase additional items which could end up being swallowed up within the fuel budget.
Controlling what is purchased on a company credit card could become an extra burden for the fleet manager, as items such as food or drink may be difficult to pick up without the necessary invoices being available.
Using a fuel card, fleets are able to stipulate exactly which items drivers can buy, such as solely diesel or petrol and oil.
Teresa Maynard, head of fuel at Castle Fuel Cards, said: 'If fleets want a clear and transparent fuel management process, a standard fuel card is unbeatable because it only allows drivers to buy fuel and lubricants.
'The consolidated monthly fuel card bill shows exactly what the fleet has spent on fuel, no more and no less, leaving fleet managers only with the job of separating business and private use.'
Restricting what can and what cannot be bought on a fuel card can slash fuel costs across the fleet, according to Clive Forsythe, Arval PHH's sales director.
He said: 'Fuel cards have proved more effective when it comes to minimising and controlling costs. They can be linked to a specific driver or vehicle and restrictions can be imposed on particular fuel types or other products. Fuel cards have the added benefit of providing back-up detailed management reporting, advice and consultation.'
Fraudsters are able to target all methods of payment but, with the latest chip and PIN technology, both credit cards and fuel cards are becoming more secure.
One of the advantages of using a fuel card management system is that discrepancies that occur can be picked up almost immediately.
A spokeswoman from fuel audit group McKinnon & Clarke said: 'An advantage of using a fuel card is that any security issues can be picked up quickly, as invoicing is done weekly, and irregular card activity can be identified and reported.'
However, despite the management benefits of fuel cards outweighing those of credit cards, there are some advantages to using a company credit card, one being that it can sometimes help in sticky situations.
Riggens said: 'There are some advantages of using a credit card. If there is an emergency and a business driver needed to check into a hotel they could pay for it on the credit card. Also, if a company needed to increase the credit terms they could do so on a credit card whereas you do not have revolving credit on a fuel card.'
However, when weighing up the pros and cons of fuel cards, the idea of streamlined costs, improved management and driver monitoring must be a plus on any fleet wish list.