driving with the A/C on most of the time now... got 22 MPG last week... previously i got around 19-20 with the A/C on

just letting everyone know about the added bonus

 

The spacer probably leaned out your A/F ratio a bit, hence the better MPG.

 

makes sense

 

A/F ratio is precisely controlled by O2 sensor regardless of any non software mods you make. The CATS only function over a very very narrow 14.7 A/F so precise control is necessary.
Anything that will improve EPA MPG [even 0.5 MPG] is worth millions to manufacturers since they must pay penalty taxes based on MPG for each vehicle sold.

 

It's probably a slight increase in engine efficency. Or the low end torque increases allow you not to have to press the go pedal as far down when crusing around town.

 

i was thinking it might have improved efficiency since the front cylinders can now breathe better

a 10% increase is pretty nice, especially since it also comes with some power

 

makes you wonder why our engines never came like that from the factory

 

What amazes me is how Tony found this inefficency!

 

There were actually a few companies in Japan that had created spacers, but they were extremely expensive. This was way back in 04/05 I believe.