Will removing cat give better mpg?

Turtle_Wax · Post by **Turtle_Wax** » Fri Sep 01, 2006 8:03 pm

If I replace the cat with a straight pipe on my Lanos 8v will it give better fuel consumption? I'm not too bothered about gaining performance as I mostly drive in congested city traffic, but if it gives better mileage then I might consider replacing the cat.

MMamdouh · Post by **MMamdouh** » Fri Sep 01, 2006 10:05 pm

if this is your driving style then removing the CAT won't do much to you if anything at all.

removing the CAT helps exhaust flow at high engine revs... 4500+ RPMs so it won't help in your case as you are not pushing that much exhaust to make the engine run out of effecency (i.e. use more fuel for the given output).

MMamdouh

Aneab · Post by **Aneab** » Sat Sep 02, 2006 7:34 am

MMamdouh wrote:if this is your driving style then removing the CAT won't do much to you if anything at all.

removing the CAT helps exhaust flow at high engine revs... 4500+ RPMs so it won't help in your case as you are not pushing that much exhaust to make the engine run out of effecency (i.e. use more fuel for the given output).

MMamdouh

+1

Also if i remember right you lose a bit of torque but gain some hp... so you wouldn't be as quick to get off the line unless you pushed the gas down even farther... so you'll be using more gas... But don't quote me on that, as i'm not 100% sure...

Turtle_Wax · Post by **Turtle_Wax** » Sat Sep 02, 2006 9:57 am

Thanks guy's. Think I will leave it in place. I do a lot of stop / starts so prefer to have a bit more torque to pull away instead of more hp. Cheers.

MMamdouh · Post by **MMamdouh** » Sat Sep 02, 2006 10:32 pm

Aneab wrote:Also if i remember right you lose a bit of torque but gain some hp... so you wouldn't be as quick to get off the line unless you pushed the gas down even farther... so you'll be using more gas... But don't quote me on that, as i'm not 100% sure...

+1

MMamdouh

Aneab · Post by **Aneab** » Sun Sep 03, 2006 12:47 am

Also, i'm not sure where you're located, but removing the cat in the US is illegal in most areas (if not all) What i would suggest if it's for a daily driver is to pick up a high flow cat... I helped put one in another car, and the restriction was reduced a pretty decent amount... He lost some torque, but definately not as much as you'd lose with removing it, but he picked up a better top end HP... And he's still complying with the law.