Asda drivers warned to 'avoid' petrol forecourts and fill up at Tesco instead

The latest supermarket petrol price watch shows Tesco is now CHEAPER than Asda. Drivers who fill up at Asda are being warned by the RAC that the average is now 147.9p, with the lowest 139p and highest 175p - a whopping 36p difference.

Tesco, meanwhile, is averaging 146.5p - two pence cheaper than Sainsburys - with the lowest found 138.9p and highest 148p, just a 10p difference. The cheapest for Sainsbury's was 139p, with the highest 13p more expensive at 152p.

Morrisons had an average of 147p - making it the second most expensive behind Asda, with a lowest, highest and difference of 142p, 149p and 7p respectively. Across all brands, the average price is 150p, the RAC has found this month.

READ MORE UK tourists in Spain risk £5,000 fines over little-known '200 litre' water rule

The retailer which is in charge of prices may not be the same. For instance, seeing the BP brand on a forecourt isn't necessarily an indication that the forecourt is owned and operated by BP, as the company's fuel is sold by a number of different retailers - not just BP itself.

Asda supply comes "from UK oil refineries and from importers who all have to meet the same rigorous quality standards," the supermarket says. "Our fleet of dedicated tankers ensure the quality of the fuel is maintained from the refinery right through to the forecourt," it adds.

Tesco Momentum 99 petrol "contains a special blend of additives to help keep a car's fuel system clean and working at its best," the supermarket giant explains on its website. The UK's largest grocer adds: "Additionally, the higher octane level (99 compared to 95 for regular unleaded petrol) gives improved overall engine performance for cars that are able to take advantage of this (generally, sportier models)."

"Most Tesco Petrol Filling Stations across England, Scotland and Wales stock Momentum 99. We don’t currently have a supply terminal that is able to produce our high octane base fuel to blend with our exclusive additives in Northern Ireland," it says.