ST ebay header and fuel economy Options

[dutchboy]

Thinking about getting an ebay header for my 94 ST, and wondered about the effect on fuel economy.

People have said that the ebay header moves power up into the higher rpms.

Now, will less power in the lower band mean better or worse gas mileage for city driving? How about highway speeds?

Also, how much does the ebay header weigh VS. stock exhaust manifold?

Thanks