The logo, circa 2001.

"the POWER-FUEL people!"
Sparki Power Fuel is a power corporation in Grand Theft Auto III. Tho logo of the company can be seen on the side of Mule trucks in Liberty City, but other than that, they are seen nowhere else in the city. Their slogan is "the POWER-FUEL people" referring to powerful, suggesting that Sparki Power Fuel is a huge corporation.

A Mule with the logo