PDA

View Full Version : Significant gas mileage drop after Simota CBII SRI + Mazdaspeed 3 exhaust installed?



tubbyc
01-21-2015, 08:09 PM
I have a 2011 Mazda 3 Sports 2.5L , after installing Mazdaspeed 3 exhaust + Simota CBII SRI I am avg. >12L/100km, I use to average 9.5L/100km mixed city+hwy..and there is no change in driving habits at all, I actually tried to drive slower and less jack rabbit start now due to a big decrease in the fuel economy. Anyone else experienced significant drop in gas mileage after installing Simota CBII SRI or any intake + exhaust mod?

Stathakos
01-21-2015, 08:23 PM
you need a tune. Engine breathes better thanks to the SRI and the exhaust, thus giving the engine a lot more air in the Air/fuel ratio. To compensate, the engine adds more fuel to balance it out. A tune will smooth things out and restore your fuel economy. Perhaps even better than stock.

Also, not to mention the colder weather will not help you at all when it comes to fuel economy.

coppermica
01-22-2015, 12:07 PM
where would one go for one of these tunes? mazda dealership or a performance shop?

Rogreborn
01-22-2015, 07:15 PM
Would have to get to a dyno and tune that way. Or wait a bit, Mat at OVTuned is going to release a bunch of free tunes and how to's, so you can tune your car yourself with a mazdaedit licence and tactrix 2.0 cable.

tubbyc
01-24-2015, 02:58 AM
you need a tune. Engine breathes better thanks to the SRI and the exhaust, thus giving the engine a lot more air in the Air/fuel ratio. To compensate, the engine adds more fuel to balance it out. A tune will smooth things out and restore your fuel economy. Perhaps even better than stock.

Also, not to mention the colder weather will not help you at all when it comes to fuel economy.
AH, I see, thanks.
I didn't expect such a drastic reduction in fuel economy. The performance gain is rather minimal, not really worth paying the extra gas for it in my opinion. I guess I will keep the setup for now, and change back to stock once the fuel price gone back up. Or wait for the free tune to become available, according to Rogreborn.

greyseason
01-24-2015, 06:43 AM
you need a tune. Engine breathes better thanks to the SRI and the exhaust, thus giving the engine a lot more air in the Air/fuel ratio. To compensate, the engine adds more fuel to balance it out. A tune will smooth things out and restore your fuel economy. Perhaps even better than stock.

Also, not to mention the colder weather will not help you at all when it comes to fuel economy.
He has a GT 2.5


OP, disconnect the,negative side of the battery, reconnect, and go for a drive to reset,your fuel trims. I think it's 75km

p-o-g-i
01-24-2015, 11:26 AM
OP, I know that for the most part after doing those mods and driving the same way, most people see better fuel consumption.

Problem being is that most people tend to push it harder after these mods to hear the exhaust and intake....

tubbyc
01-24-2015, 09:14 PM
I actually did reset two times, with disconnecting the battery and push on high beam a few times. It didn't help with the fuel economy, intially, i thought it was because ECU needs to re-learn the map. I didnt push the car harder at all, I actually tried to drive much slower than before, even on highway, without traffic in the middle of night, driving steadily around 100km/h, I am only getting 9.3L / 100. If you guys are actually getting better fuel economy with similar mod, then I really dont know what is wrong with my setup. I was told to put back the stock air intake to see if the Simota CBII is the one that;s causing a reduction a fuel economy. BTW, I live in Vancouver, so the weather here is not as cold as in Toronto, so the cold temperature shouldnt be a big factor here I think. I actually installed the Mazdaspeed 3 exhaust 3 days before the intake. I started to notice a decline in fuel economy with that. Is it possible the exhaust maybe a factor too? thanks

tubbyc
02-23-2015, 10:09 PM
After changing back to my stock air box, the fuel economy dropped back down to about 10.5 L /100km from 13.5 L /100km (since my last post, my fuel consumption became hovering around mid 13). Couldn't get it back down to below 10L / 100km anymore, maybe it is because I upgraded to 225/40/18 tires from the stock one. nevertheless, much better than the 13.5 L/100km i was getting.

mEtH
02-23-2015, 10:31 PM
Well it is winter time. You have winter tires on? With the extreme cold over the last week or so it does take longer for your tires to warm up and expand to their proper inflation. It's hard to compare all your specs with such changes in the weather. When you are talking about the previous mileage, when exactly was that, what sort of conditions?

Just something else that could possibly account for a change in mileage.

The Wolf
02-23-2015, 11:05 PM
a) both the intake and the exhaust will diminish fuel economy with no other factors.
b) it's crazy cold right now which hurts fuel economy
c) you're probably standing on the gas pedal a little harder than you were before

tubbyc
02-24-2015, 04:16 AM
oh.. I actually live in Vancouver. so my previous gas mileage (>13L/100km) was for the past 3 weeks or so, when the weather is about the same as of now unlike Toronto. I actually have been driving more conservatively than in the past, trying to bring down the fuel economy given the gas price has climbed back up, however, still consistently getting >13L/100km with mostly city driving. Guess I will stick with my stock air box for now then..

Punkrockjohn
02-24-2015, 10:02 AM
a) both the intake and the exhaust will diminish fuel economy with no other factors.
b) it's crazy cold right now which hurts fuel economy
c) you're probably standing on the gas pedal a little harder than you were before

+1