Motoring groups yesterday welcomed a deal by Coles and Woolworths with the competition watchdog to restrict the use of shopper dockets.

The Australian Competition and Consumer Commission has struck an agreement with the supermarket giants to limit fuel discount vouchers to 4 a litre, except where the discount is funded by their fuel retailing operations.

This means that from January 1,  discounts funded by non-fuel retailing operations are limited and any discounts above 4 must be funded by convenience stores or other activities at their service stations.

An RACT spokesman said anything that increased competition was a good thing.

``They now have to compete within their [petrol station] cost structures rather than leverage off their supermarket operations,'' he said.

``Anything that removes market distortions is a good thing.

``We want to wait and see what the effect of the [ACCC] undertakings are.''

Jims Car Care Centre owner Tony Lowish said his Prospect service station found it tough going against shopper dockets.

Mr Lowish said he would like all shopper dockets banned, as independent operators did not have the cross-subsidisation capacity of the big supermarkets.

Tasmanian Automobile Chamber of Commerce general manager Malcolm Little said the decision was a good one because shopper dockets were anti-competitive.

Mr Little said even though motorists got a fuel discount, someone had to pay, as supermarkets were profit-driven.

Australian Automobile Association chief executive Andrew McKellar said an association survey found 78 ?per cent of motorists used shopper dockets but only 42 ?per cent believed they actually saved money.

``Motorists are smarter than the supermarkets think and they realise that reducing competition will end up costing them money in the long run,'' he said.