bobbyd

iTrader: (10)

it seems that when I have my cutout open my gas gauge goes down faster.

does having the cutout open cause the car to lose mpg's?

Websy21

iTrader: (34)

Its probably b/c you have your foot into it more since you want to hear it

bobbyd

iTrader: (10)

could be true i guess although I usually just run about the same speed with it open and closed

Websy21

iTrader: (34)

Ya not to sure, I got an electronic one and I'm always playing with it and don't really see the difference in mpg but I haven't calculated b/w them so I really don't know. It couldn't be that significant you wouldn't think.

BTW, where is it located? I got mine on a borla catback at the rear, is yours right under the car? I am pretty sure that straight free flowing isn't as efficient as a good exhaust system.

LS184

iTrader: (7)

bobbyd

iTrader: (10)

Yea thats what I have aswell a electric one.

I have it located right under the rear passengers seat right before over the axle.
i see the gas gauge go down sometimes I wonder if its the pressure or something lol

Empatho

iTrader: (16)

its probably because it makes the car run rich

bobbyd

iTrader: (10)

yea i was just reading about the a/f ratio so I guess thats the reason.

apparently a tune will fix that problem but I will just wait till after this week or so since this weekend im getting my LT's installed and might need to have the rear o2's tuned out.

5SiX1

iTrader: (2)

i ran my car with the cutout off for an entire tank and got .2 better MPG than with the cover on. mine is also located right under the passenger seat.

406malibu

wont hurt your mpg unless you stay in it to hear the sound

miamifan3413

iTrader: (1)

On the highway you'll get better gas mileage....I got 2mpg better with it open on my trip from tampa fl to kentucky. In the city it seems that I lose mpg....i'm guessing because the torque moves up in the rpm band so you have to step on it a little more to get moving.

bobbyd

iTrader: (10)

hmmm do you have a tune by any chance? since I read that you can get a tune and have the air and fuel ratio change so that it wont use more gas that way

malott442

I have an SLP dump, and I have kept it capped for the past year. With the exception of it sounding sweet, nothing benefitted from it.

I of course didn't tune it for it though.
And after I added straight pipes instead of a flowmaster........ It doesn't need the dump to be loud...

But when I had the flowmaster, I took it off and on several times in one day, testing the difference.

The city mileage suffers with a dump.... the highway mileage was almost dead even, the sound in the car of course was so much sweeter with the dump, but with it closed you could at least hear the passenger in a normal tone of voice....

And stomping on it a few times, it seemed like the dump really hurt it off the dig, and might've given it a smidgen more top end....... All in all, I decided the dump was a bad idea and kept it on.

Then 3 months later the cap fell off, and I had to weld up a new one, so i loc-tited that sucker on and have forgotten about it since.

Dumps on the y-pipes seems to be the best solution for drag/top end..... the right before axle like you and I have is just there to make some noise...

I may be wrong, just my 2cents

I know I'm planning on electrics on the y when I replace the exhaust this winter...

BRRRAAAAP!

5SiX1

iTrader: (2)

i haven't tuned the car since i've owned it. the previous owner put the cutout in. i'll be doing a full exhaust job soon, long tubes, e-cutout, ORY, etc. and i'll get a tune then.

bobbyd

iTrader: (10)

Same here. i got the LT's and ory ready to go on this weekend i already have the e-cutout and then I will get a tune.

i guess whats killing me its like how many of you guys have said that in the city it does eat more gas I guess thats where im seeing the gause go down a little quicker.

NC98Z

iTrader: (1)

Mine was open when the A/F was set. So I loose MPG when its closed and I lose my hearing when its open.

therealcreeper

iTrader: (37)

i think i get better gas mileage around town with my cutout open, since i'm trying not to attract cops and be obnoxiously loud. once you break 2k rpm it gets louddddd so by keeping it quiet i'm also improving gas mileage. with it closed i totally forget and just fly around town.

WhiteFormula98

iTrader: (10)

cocaine is a hell of a drug

fccs

iTrader: (26)

Usually because of less restriction you WILL get better MPG city and highway with a cutout open. Also with a ORY you will get a improvement. The problem is usually you dont notice but you tend to shift at higher points because.. you wanna hear the sound more and that is where it either evens out or causes your mpg to be 1 or 2 less depending on how you drive.

O-townLS1

Mine was located under the rear passenger seat. With it open, It seemed to use less fuel if I stayed in it a few times. If i just cruised it seemed like the gas gauge would just drop. With it closed, it would get better gas mileage if I was just cruising around but if I went WOT just a couple times the gas gauge would drop. I never understood it. Oh well.