[dcb]

Originally Posted by roflwaffle

It's not a mistake, just out of context (Use the search Luke! ).

It is the claimers job to provide context, internet is a big place with lots of contradicting information.

Originally Posted by tjts1

...High FE is goes from 33 to 40. ...
Who says exhaust work can't yield FE?

From the waffle link, the engine sees "%15 improvements in mpg".

And the exhaust mods are listed under "Anti-knock", and force retarded ignition as well.

So it still doesn't add up from several angles.