Just wanted everyone to know my average fuel economy is improving as my cheap autozone O2 sensor and single Magnaflow CAT are breaking in.

First tank ~220 miles (15.5gal)
2nd tank ~250 miles (15.5gal)
3rd tank ~275 miles (15.5gal)

So hopefully I'll be close to my original 300miles/tank here pretty soon which is ~20MPG. That's V6 honda accord fuel economy

Mods are partial headers (NA Vert downpipe), Single High-flow Magnaflow Cat, HKS Mufflers, OEM catback piping.

 

If you want real economy I suggest a Haltech. Mine has easily paid for itself already over the last couple years.

 

Numbers? :-P

I'm replacing my O2 sensor this weekend (assuming I can get it out - I'm pulling the exhaust manifold off to work on it). I've been getting 20-22mpg, I'll know if it's better afterwards.

-=Russ=-

 

Maybe my math is off but 300 miles on a full tank @ 18 gallons is 16.6 MPG. I just changed my O2 sensor with an OEM on low mileage car (50K) and now getting 18.5 city.

 

30mpg on the freeway, so far. After I install an egt bung I will shoot for 35-40mpg. I've heard of others getting that much with Haltechs..

 

Nobody actually drains their tanks between fillups. I usally only put in ~15 gallons on Monday and drive ~300 miles during the week. With my lead foot ~20MPG is pretty darn good.

Besides the Haltech, the freeflowing exhaust pays for itself in fuel economy. This is partially why an RX-8 with 2500miles on it gets better fuel economy than the "3 cats NA RX-7s" do.

 

Has anyone use the NGK o2?

 

Wish Mazda would do this, but guess they have to keep the CAT cool to extend its life ... which means richening up the air/fuel ratio which nets less fuel economy.

Also wish Mazda would program in a "antiflood fuel cut" when you turn the car off. Seems simple enough to prevent flooding.