A universal refueling funnel for a capless refueling system is provided. In one example approach the refueling funnel comprises a funnel body with a first opening at a first end and a second opening at a second end opposing the first end, the first opening larger than the second opening, and cross-sections of the funnel body decreasing from the first end towards the second end; and at least two opposing tabs at the second end, the opposing tabs deformable from a first position to a second position, a distance between outer surfaces of the opposing tabs at the second end being a first amount in the first position, the distance being a second, smaller amount, in the second position. Such a universal funnel may be used for both petrol and diesel size capless inserts, for example.