Drivers are being warned to avoid certain petrol stations if they wish to save money.
Fuel at motorway services is often pricier than at supermarket stations.
This is because petrol firms have a "captive audience" at services, experts say.
According to the Daily Express, a spokesman for Ocean Finance said: " Never top up your fuel at a motorway service or near a motorway exit.
“Even though fuel prices have risen across the board, not all petrol stations are charging the same amount.
“As a general rule, petrol stations at motorway services, or near motorway exits, tend to be the most expensive."
This is because fuel firms know they have a "captive audience" at service stations, Ocean Finance said.
Drivers can use apps like PetrolPrices to find the cheapest deals in their area.
Petrol currently costs on average 164.89p a litre, while diesel is 189.51p.
It comes after Sainsbury's joined other supermarkets in upping the minimum cost of pumping up tyres at its petrol stations to 50p.
The store used to have the cheapest cost for supermarket tyre pumping, which previously to cost 30p for three minutes.
This has now changed to 50p for five minutes, matching the cost of Tesco, Morrisons and Asda.
It marks a 20p increase overall, in terms of the minimum amount you have to spend, although drivers are still paying 10p per minute.
Shoppers have been reacting to the change on social media.
One wrote on Twitter : "The tyre pressure machine at Sainsbury’s Banbury went up from 30p to 50p."
They continued: “It has always been 30p. Now they hike it 66%. Same machine. Just a sticker over the price.
"OK, it’s a small thing. But there are so many opportunistic price rises happening now."
The change in price, which was first reported by The Sun, came into effect in July.
A spokesperson from Sainsbury's told The Mirror: "Back in July, we started offering customers five minutes rather than the previous offer of three minutes, with each minute remaining at 10p per minute.
"This is in line with the wider market offering and based on customer feedback."
Drivers should aim to check their tyre pressure every two weeks as driving with them over or under inflated can be dangerous, the AA recommends.
The update comes after the boss of Sainsbury's warned shoppers are "watching every penny and every pound" as food prices continue to rise.
Chief executive Simon Roberts said life is “tough for millions of households” who are also battling against sky-high energy bills.
The supermarket recently revealed its pre-tax profits fell by 8% to £340million after being hit by higher costs and higher wages.
Sales rose by 4.4% to £16.4billion in the six months ending in September.
Mr Roberts said: "We know [customers] are relying on us to keep food prices as low as we can.
“We will have invested more than £500million by March 2023 in keeping prices lower by cutting our costs at a faster rate than our competitors, meaning we have more firepower to battle inflation.
“Over the past year and a half we have consistently passed on less price inflation than our competitors and I am confident we have never been better value.”
