The average cost of a gallon of regular unleaded gas hit $5 across Long Island on Wednesday, but some stations are charging much more.

A Shell gas station in Commack is charging $5.49 a gallon if drivers pay with cash. Paying with a credit card will cost $5.79 a gallon.

Right across the street at a Cumberland Farms, the price is $4.99 a gallon.

"If I had seen that I might have gone to the other one," says Jordan Chambers, of Dix Hills. "But I generally don't look, I just pull up and go."

Suffolk County is investigating eight complaints of possible price gouging.

Robert Sinclair Jr. with AAA says there is no fixed price increase that constitutes price gouging, but drivers should look carefully before they fill their tanks.

"If everybody is charging $5 a gallon and one stations is charging $5.25 or $5.35, you could define that as gouging," Sinclair Jr. says.

On Wednesday, Suffolk County inspectors were investigating a Sunoco station in Elwood, where they were charging an extra $2 per gallon to use a credit card.

A gas station in Valley Stream was fined by Nassau County on Tuesday for charging an extra 90 cents to pay with a credit card.

Chris Daniello with the Long Island Gasoline Retailers Association says many gas stations are raising their prices to cover higher costs.

"Wholesale prices have been going up every day," Daniello says. "10 cents, 15 cents, 18 cents a day, we've been seeing increases on the wholesale level."

It's not clear how many gas stations are being investigated and it's unknown if inspectors are actively searching for gas stations or responding to complaints.

Democratic legislators in Nassau County plan to contact County Executive Bruce Blakeman's administration and the Department of Consumer Affairs Thursday to find out what is being done to prevent price gouging.