I was searching for something (forgot what) and found this from a very old test of the "new" 2002 Trailblazer from TestDrive.com.
I saw this in the text, "By the way, added chief engineer Ted Robertson, there's another 30 horsepower to be had just by going to dual exhausts. Aftermarket manufacturers are probably bending pipes now.".
That has to be a big exaggeration, dont you think.
The whole text is here 2002 Chevrolet TrailBlazer Expert Reviews Details
Edit:
I also found this that would explain a lot,"However the estimated EPA rated mileage of 15/21 mpg city/highway is based on that optional 3.42 rear end (a legal EPA loophole) so higher" is relative."
I saw this in the text, "By the way, added chief engineer Ted Robertson, there's another 30 horsepower to be had just by going to dual exhausts. Aftermarket manufacturers are probably bending pipes now.".
That has to be a big exaggeration, dont you think.
The whole text is here 2002 Chevrolet TrailBlazer Expert Reviews Details
Edit:
I also found this that would explain a lot,"However the estimated EPA rated mileage of 15/21 mpg city/highway is based on that optional 3.42 rear end (a legal EPA loophole) so higher" is relative."