ProECM/TC2 Questions-- Mileage and Emissions

DrBoy01 · 03-11-2003, 02:28 PM

DISCLAIMER: This is NOT about the HP/torque performance of either chip brand. That issue has been beaten to death by several threads and I would like for it to not be discussed in this one.

Recently I've come very close to buying a ProECM or TC2 v2.7 for my 02 2.5 RS 4EAT. The only issues keeping me from buying one is the question as to whether installing a chip will decrease my mileage and increase emissions.

It has already been established that both chips act to increase ignition timing. Is there a correlation between an increase in timing and a decrease in mileage? If so, would the increase in timing be offset by adding 91 or 93 octane gas, as both chips require? If you have a chip in your NA Impreza, how has your mileage been affected?

What about emissions? If the timing is increased, would I be less likely to pass my states' emission test in a year or two? If you have a chip, what have your experiences been when you pull into the DMV or a private inspection shop to get your emissions tested?

Thanks in advance.

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DanzBorin · 03-11-2003, 04:20 PM

actually in this case, the increase in timing will increase your gas mileage if you don't drive too fast...

Just like most any other perf. mod...

joefocker20 · 03-11-2003, 05:17 PM

Your car is also emissions exempt for 3 more years..

scoobiejosh · 03-11-2003, 06:51 PM

An advance in timing should increase gas mileage. A decrease in mileage suggests that it also adds more fuel which hurts performance unless you have a lot done to the car. As in along the lines of heads and cams.

joefocker20 · 03-11-2003, 08:11 PM

Im not sure if my Intake or my PROECM causes mycar to run more rich, I have a VERY sooted exhaust..

DoorKnob · 03-15-2003, 04:38 PM

With my TC2, my mileage is almost exaclty the same.

03-11-2003, 02:28 PM	#1
DrBoy01 Scooby Specialist Member#: 20444 Join Date: Jun 2002 Chapter/Region: MAIC Location: Wilmington, DE\|Berkeley Vehicle: 2006 Outback 2.5 XT Garnet Red Pearl 5MT	ProECM/TC2 Questions-- Mileage and Emissions DISCLAIMER: This is NOT about the HP/torque performance of either chip brand. That issue has been beaten to death by several threads and I would like for it to not be discussed in this one. Recently I've come very close to buying a ProECM or TC2 v2.7 for my 02 2.5 RS 4EAT. The only issues keeping me from buying one is the question as to whether installing a chip will decrease my mileage and increase emissions. It has already been established that both chips act to increase ignition timing. Is there a correlation between an increase in timing and a decrease in mileage? If so, would the increase in timing be offset by adding 91 or 93 octane gas, as both chips require? If you have a chip in your NA Impreza, how has your mileage been affected? What about emissions? If the timing is increased, would I be less likely to pass my states' emission test in a year or two? If you have a chip, what have your experiences been when you pull into the DMV or a private inspection shop to get your emissions tested? Thanks in advance. * Registered users of the site do not see these ads.

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03-11-2003, 04:20 PM	#2
DanzBorin Subaru Bounty Hunter Moderator Member#: 7131 Join Date: Jun 2001 Chapter/Region: TXIC Location: Houston - Back in the Alief Vehicle: 2008 STi DGM (3rd STI) prev 05 STi (white)	actually in this case, the increase in timing will increase your gas mileage if you don't drive too fast... Just like most any other perf. mod...

03-11-2003, 05:17 PM	#3
joefocker20 Scooby Specialist Member#: 13745 Join Date: Dec 2001 Chapter/Region: RMIC Location: Colorado Springs, CO Vehicle: 2004 STI Silver	Your car is also emissions exempt for 3 more years..

03-11-2003, 06:51 PM	#4
scoobiejosh Scooby Specialist Member#: 3139 Join Date: Dec 2000 Chapter/Region: RMIC Location: SLC Utah Vehicle: 2001 Dodge Pikumup & 08 Triumph Speed Triple	An advance in timing should increase gas mileage. A decrease in mileage suggests that it also adds more fuel which hurts performance unless you have a lot done to the car. As in along the lines of heads and cams.

03-11-2003, 08:11 PM	#5
joefocker20 Scooby Specialist Member#: 13745 Join Date: Dec 2001 Chapter/Region: RMIC Location: Colorado Springs, CO Vehicle: 2004 STI Silver	Im not sure if my Intake or my PROECM causes mycar to run more rich, I have a VERY sooted exhaust..

03-15-2003, 04:38 PM	#6
DoorKnob Scooby Newbie Member#: 395 Join Date: Oct 1999 Location: Daly City, CA USA Vehicle: 2000 Impreza 2.5RS Blue Ridge Pearl	With my TC2, my mileage is almost exaclty the same.