In the wake of higher gas prices, the Better Business Bureau has renewed it warning about a Sauk Centre company that sells a product it claims can use water to increase gas mileage..

Gertken Enterprises claims that by using its "water hybrid" product, namely its GMAX350 Hydrogen on Demand System," consumers can use less fuel. Its website boasts that "tens of thousands drivers are already utilizing this great technology." A disclaimer mentions that "tests and feedback" show the system has increased gas mileage by 25 percent and decreased emissions by 60 percent.

"Money/fuel-saving claims of this nature all have one thing in common: they are all too good to be true," said Dana Badgerow, president and CEO of the BBB of Minnesota and North Dakota. The company failed to provide requested documents to substantiate its advertising claims, the BBB said.

Last year the Federal Trade Commission put out a warning about companies making gas-saving claims. Some products may damage a vehicle or actually increase exhaust emissions, the warning stated.

The company could not be reached for comment on Monday.