Asda shoppers feeling the pinch are already asking checkout staff to stop scanning their groceries once the total hits £30 - now motorists could be doing the same on the forecourt.
Chairman of the supermarket chain Lord Stuart Rose has revealed a "massive change" has been observed in customers' behaviour amid the cost of living crisis.
He claimed Brit drivers are self-imposing spending limits when they fill up their cars and called on the Government to do more to help low-income households, Nottinghamshire Live reports.
He told the BBC : "People are trading back. They are worried about spending."
According to the latest data from Kantar, the average annual grocery bill is on course to rise by £380.
The price rises have already altered consumer shopping habits, as Lord Rose pointed out.
He said: "They've got a limit that they've set out, too.
"They say £30 is one limit.. and if they get to more than £30 then that's it, stop. It's the same with petrol."
With supermarket prices hitting a 13-year high and fuel prices rocketing, the cost of living crisis is biting ordinary households.
Manchester Evening News reported that the Asda chairman said many people won't remember the inflation of the 1970s and the current rise in prices has come as a shock to many.
He added: "I'm of the generation that remembers what it was like last time. And once [inflation] gets hold, it's quite pernicious."
He went on to say that some people are heading to self-checkouts to avoid the embarrassment of not being able to pay.
The average price of a litre of petrol at UK forecourts reached a new high of 189.3p on Tuesday, according to data firm Experian.
The average price of diesel was 197.1p per litre.
The rate of inflation rose again in May, remaining at 40-year highs and deepening the squeeze felt by households across the UK, the Office for National Statistics (ONS) has said.
