It's a pump so by nature it creates a vacuum to pull fuel. If it didn't have a pump it would be gravity fed. I wouldn't think it would have a problem pulling fuel 15 feet unless it was pulling it UP 15 feet. (i.e. motor is 15 feet higher than the fuel tank.) Sounds like your making a cycle powered car? Pics would be cool.
Some of the 15feet will be up(from under the car floor up to the carbs), but most will just be on a level.
I can either mount the pump in the engine bay and have it "pull" fuel 15+feet, or can mount it near the fuel tank and let it "push" fuel 15+ feet.
It will be a bike carb powered engine, but the engine is a original car one, not a R1 engine.