Two teenagers have died after drinking a deadly cocktail of racing fuel mixed with Mountain Dew.

Two other people were left ill by the drink, which they called "Dewshine", according to officials in Tennessee, USA.

Authorities believe the teens were trying to use the poisonous methanol as a substitute for ethanol, which causes intoxication in alcoholic drinks.

"That was their intent," said Tennessee Poison Center Medical Director Donna Seger. "Unfortunately methanol is extremely toxic."

A toxicology report on one of the teens who died confirmed he had ingested methanol. It was not clear how much the teen had drunk but officials said it was "a lot".

Police said they drank the methanol on January 20, with one dying the next day and another on Monday.

The two other teenagers have been discharged from hospital.