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Discussion Starter #1
Hey guys!

Just wanted to touch base with you about a possible "problem" with my '10 3 GT - 2.5/6speed. Recently moved from Jacksonville, FL to Atlanta, GA so my commute has changed pretty drastically. Went from a 25 mile each way 70% highway/30% city - to a 3.6 mile 100% city (~20 stoplights going in), 3.4 mile return 100% city (~12 stoplights coming home), generally only catch I would say about 30-35% red lights.

Prior to now I had no trouble meeting EPA estimates and no trouble with exhaust smells. I have been doing my new commute going on the 4th week now and have had to fill my tank for the first time since I started my new job - achieved an absolutely ABYSMAL 17.7 MPG or about 3.3 MPG below EPA city figure. I don't race around and generally shift ~2700-3300 RPM, speed limit along my commute is 35 MPH but the traffic generally travels 10-15MPH above that so I just stay with the flow.

Now I know my mileage is going to suck due to the city driving and constant stoplights however the exhaust smell has been continuously getting worse to the point I can smell my own car when stopped with the drivers window down about 4-5" and even after I have shut it down and am walking around the rear end of the car. It is a mixture of rotten eggs and the smell when a match burns out. My last tank was a Chevron and this tank I used a different Chevron station to see if maybe it was a tank of bad gas.

Should I be concerned about the smell and bad mileage or just wait until my next service to bring it up? My annual mileage has dropped considerably so I will be switching over to an annual service vs mileage based as I will be doing MAYBE 4,000 miles a year max.

Thanks in advance!
 

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I don't know about the egg smell, but your fuel economy could be attributed to your shift points. Maybe try shifting between 2000-2500 RPM. And I assume since you are on Fuelly you know how to get good mileage, like getting off the gas when you see a red coming up, or watching crosswalk timers (if you have that). There are plenty of ways to eke out a few more miles per tank.
 

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Discussion Starter #4
The rotten egg smell would indicate that a cat isn't doing it's job. Or a faulty primary O2 sensor could be to blame, as it wouldn't report proper exhaust readings and you are running pig rich. If you are under warranty go to the dealer
Will definitely have it checked out at my next service visit if the smell and horrible gas mileage persists - I have a full year and month and ~6k left on my bumper to bumper so I am not in too much of a hurry unless the CEL lights up.

Car seems to be running as it always has which is why I was wondering WTF was going on. I know my commute is borderline automobile abuse but after a month of my commute I figured 15-20 minutes of driving around at ~2000 RPM would be sufficient to keep things running smoothly.
 

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Discussion Starter #5
I don't know about the egg smell, but your fuel economy could be attributed to your shift points. Maybe try shifting between 2000-2500 RPM. And I assume since you are on Fuelly you know how to get good mileage, like getting off the gas when you see a red coming up, or watching crosswalk timers (if you have that). There are plenty of ways to eke out a few more miles per tank.
2,000 RPM shift points would be suicide here in ATL. :) I have mis-calculated on occasion and was in 3rd around 1300 RPM and it was horrifically slow, I know the 2.5 is a "big" 4 cylinder but it is absolutely gutless down low. My shift points generally keep me with the flow of traffic and I will probably keep them that way....for the simple fact I have no desire to piss off Atlanta drivers (guns being involved in road rage incidents seems to be quite common here).

I do generally try to drive in a conservative manner, coasting in gear as long as possible to stoplights, using the crosswalk timers to either make the light or coast when I know I won't.

I am really just surprised I was able to get 1 MPG below EPA hwy during my 70/30 commute whereas I cannot even hit the city figure to save my life even with the same driving style - not to mention the smell. I know the smell is normal if you are going WOT, but how horrific it has been during just normal day to day driving is a new thing for me.

I may go for a long highway run before the week is out to see if maybe I just need to get things burned off.
 

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not entirely true on the rotted egg smell, that means you have an abnormally high amount of sulfur in your gas, which isn't being burned off enough and stinking it up, try a better gas station because the one you might be going to has shitty gas, and they add sulfur to make it cheapa, your car can be fine and just got some really garbage gas, it's sulfur content I promise
 

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I run pig rich on 1 cat and don't get that smell. It's shitty gas. Try a different station this happened to me, and I was wondering why my car stank so bad. It's takes easily 3 full refills of gas with light sulfur content to make the smell diminish from ur exhaust
 

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Discussion Starter #8
I run pig rich on 1 cat and don't get that smell. It's shitty gas. Try a different station this happened to me, and I was wondering why my car stank so bad. It's takes easily 3 full refills of gas with light sulfur content to make the smell diminish from ur exhaust
I filled up using a different station (another Chevron....I always use Chevron for fuel) today assuming my last tank was bad so will see if it improves. If this is the case it is amazing to me that station owners can get away with this - especially in an area that mandate annual smog checks for vehicles 3+ years old. :argh 1:
 

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Go to Jim Ellis Mazda of Marietta in ATL! That is where I bought my car, they are very friendly there.
 

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Sulfer smell is most likely 2 things, 1 your commute is so short the cat doesn't reach operating temperature and 2 the type of fuel you are using. The amount of sulfer content and a cat not fully being able to do a proper job.

try toptier fuels, there site will give you a break down on stations.

for the milage, its similar. I bet if you pull your oil cap it will stink like fuel and possibly frothy... The stop and go with short distant is killing your milage.
 

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17mpg is not terrible for a 2.5 only city driving.... especially with 4m drives each way to and from work where the vehicle is struggling to warm up.

We live in a small city and most people commute 1-10km a each way, we have tons of people come in complaining fuel economy sucks. Mazda then has us drive 40km at 80km/h without cruise on... meraculusly the mileage goes right back up to spec.
 
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