National Car Rental's (NCR) vehicle groupings have now been revised according to engine size and vehicle type.
Kim Brown, marketing director, said: 'The UK car parc has changed dramatically in the past few years along with our fleet. This major realignment of our fleet groupings is a reflection of our commitment to listen and respond to the needs of our customers.
'It means that not only will our customers' expectations be met, but they may also find that they can make cost savings by choosing more cost-effective car groups appropriate to the needs of their businesses.'
Within this revised system there is, for the first time, a grouping specifically for seven seat multi-purpose vehicles such as the Vauxhall Zafira and Renault Grand Scenic when it is launched, reflecting the growing popularity of such vehicles in the rental market.
These cars will come in a new 'Q Group', with NCR claiming it is the first rental company to create such a grouping.
According to operations director Brian Jays, the Zafira was previously grouped with the Astra estate due to its flat loadspace, but more customers now want it for its people-carrying ability.
He said: 'I don't doubt that the mini-MPV market has grown significantly in this country and people booking from the previous grouping were increasingly wanting a Zafira rather than an Astra estate.'
The shifting requirements of customers have also led to National expanding its choice of large premium automatic estate cars, now banded together in a 'G Group'.
These include the Saab 9-5 estate, Volvo V70 and MG ZT-T. Jays claimed that the end of big volume cars such as the Vauxhall Omega had meant the semi-premium brands were becoming increasingly popular.
Customers have also expressed interest in the sports utility vehicle (SUV) sector. National, Jays said, did run a fleet of Vauxhall Fronteras and Nissan Terranos some years ago, but these were discontinued. The surge in models such as the Land Rover Freelander and the imminent BMW X3 means such cars are now a viable rental sector. The SUV group and available models will be announced at a later date, with a possible launch in the spring.
Brown added: 'We have realigned the fleet to reflect the wider choice of vehicles we now offer and to ensure each group has vehicles that are 'like-for-like' in terms of engine size and type so that our customers' expectations are always fulfilled.
'For example, customers previously booking a vehicle in our 'U Group' would have been provided with a utility vehicle or an estate car.
'Now, if a customer requires a seven-seater vehicle with a 1.8-litre engine they will be guaranteed this by booking into the Q Group.'
In the UK, National Car Rental has a fleet of 35,000 vehicles operating out of 145 locations.