Help with MPG

[atalkingbear]

I'm getting about 15-16 miles per gallon, which is pretty bad. I drive conservatively, too, shifting around 2 - 2.5 RPM.

Any suggestions? My car always smells like it has unburned fuel coming out of the exhaust, but I already got the o2 sensor changed, and the car supposedlypassed smog.

 

[Doward]

Look for fuel leaks.

Get a wideband (or just go to a dyno) and see how your part throttle afrs look.

 

[87mgte]

I'm getting about 15-16 miles per gallon, which is pretty bad. I drive conservatively, too, shifting around 2 - 2.5 RPM.

Any suggestions? My car always smells like it has unburned fuel coming out of the exhaust, but I already got the o2 sensor changed, and the car supposedlypassed smog.

i get 11.3 mpg according to the supermonitor... i need help with this problem as well. i don't have any fuel smells or anything though, just shit gas mileage.:dunno:

 

[IJ.]

How old is the 02 sensor?

 

[87mgte]

How old is the 02 sensor?

i haven't replaced mine since i've owned the car, so God only knows. that's gonna be the first thing i'm replacing though. how much does that usually set a person back, like 50 bucks?

 

[atalkingbear]

Where are the typical fuel leak places? There are never any spots on the ground indicating any type of liquid leaking, so I'm not sure where to start.

 

[Poodles]

O2 sensor doesn't have enough control to cause 11.3 MPG...

TPS, AFM, boost leaks, timing...

I average around 18 these days, and my TPS is finicky and needs to be replaced...

 

[7MGTEsup]

To be getting that sort of fuel consumption you must have some serious problems. How does the car drive?? Is it lumpy on low throttle positions?? Does it bog when you step on the gas?? Maybe start looking towards leaking fuel injectors.

I had a bad o2 sensor when I got my car but it only affected fuel consumption by about 5mpg

 

[87mgte]

To be getting that sort of fuel consumption you must have some serious problems. How does the car drive?? Is it lumpy on low throttle positions?? Does it bog when you step on the gas?? Maybe start looking towards leaking fuel injectors.

I had a bad o2 sensor when I got my car but it only affected fuel consumption by about 5mpg

it drives fine and idles fine. smooth throughout the powerband no matter where i'm at with the throttle. i think i should get a tune up and change the o2 sensor cause i have no idea how old these spark plugs and wires might be. same with the o2. my exhaust manifold gasket's shot too, but would that cause poor mileage?

 

[thebuddrik]

the o2 sensor is a little above $100 bux from champion
im gona order mine after christmass

 

[atalkingbear]

The car idles around 1500 on cold weather on start up, and drops to around 1000 after a minute or two. I assume the bogging feeling is when the car feels like it isn't traveling smoothly in the low RPMs? I get that if I let the clutch engage without gassing, so in the very low RPMs, the car bogs. Aside from that, the car drives smoothly once the RPMs get a little higher.

It's an NA, by the way. I could try tweaking with the throttle position to lower the idle a bit, but I don't know how to check the AFM or fuel injectors.. Should I swap the spark plugs? If so, what company makes good plugs?

 

[Poodles]

it drives fine and idles fine. smooth throughout the powerband no matter where i'm at with the throttle. i think i should get a tune up and change the o2 sensor cause i have no idea how old these spark plugs and wires might be. same with the o2. my exhaust manifold gasket's shot too, but would that cause poor mileage?

manifold gasket being shot on a turbo car, yep, bad milage as the car is expecting the turbo to be spooling, causes all sorts of issues...

 

[mk3forme]

The car idles around 1500 on cold weather on start up, and drops to around 1000 after a minute or two. I assume the bogging feeling is when the car feels like it isn't traveling smoothly in the low RPMs? I get that if I let the clutch engage without gassing, so in the very low RPMs, the car bogs. Aside from that, the car drives smoothly once the RPMs get a little higher.

It's an NA, by the way. I could try tweaking with the throttle position to lower the idle a bit, but I don't know how to check the AFM or fuel injectors.. Should I swap the spark plugs? If so, what company makes good plugs?

you say your idle drops to 1000 after a minute or two. Its not staying that high is it?

 

[suprra_girl]

lol ya think 15 and 11mpg is bad, my supermonitor says 7mpg lmao... then i've got to -25% from that as i'm running 550 injectors... can we say... use fuel!! LOL

so i just went and converted and my mums supra gets 19mpg city!!! that's suprising lol.. she gets 59m to 3gallons

I'll check mine more accurately when a) i have a digi fuel gauge that actually works properly lol and b) i have more than reserve in the tank haha

 

[IJ.]

Suze keep in mind USG = 3.8L Imperial G = 4.5L

 

[iamshawn]

my super monitors says 18.7 mpg ^___~

got 57 trim, lex AFM, and 550 denso... 15 psi boosting about 20% of the time.