I have noticed my gas mileage is very poor lately. I used to be able to drive 340 to 360 with full tank. Now, I am only getting 260 with full tank.

The only change I did was swap out my Injen exhaust with a member on this board for his stock exhaust. I am noticing there are lots of ticking sound coming from the exhaust underneath the car when I park. Could it be a link? If there is a link, will it cause mileage issue? Any advise is greatly appreciated.

I have a 05 auto coupe with stillen intake and 5/16 spacer if that help. No other mod.

thanks in advance.

 

anyone have this issue?

 

its called winter time gas mileage goes down

 

winter gas is better than summer gas...summer gas you have more ethanol, winter gas is normal. check your air pressure, maf sensor, and air filter

 

How many miles are on your car. If over or near 50k I say you might benefit from new spark plugs.

 

38K.

 

wow i only average 200miles a full tank! wtf

 

im getting 320 on 3/4 of a tank...

 

What kind of mod to you have? I was getting 340 per tank before, but, I am not sure what is going on now. I am only getting 260 to 280 per tank. Not sure if it cause by the exhasut swap.

 

Last time you got a oil change? I had the same problem when i first got my car it was over due and the dealership didnt tell me.

 

i have never heard of winter or reformulated gas as being better for mileage than summer gas. i have heard reformulated winter gas contains any number of lighter, lower-boiling-point hydrocarbons (butane, propane, etc.) that just so happen to have an excellent octane value. Added to this may be any number of oxygen-bearing ether compounds (MTBE, ETBE, ethanol) that improve emissions and also have a relatively high octane blending value.
thats great from a performance standpoint but not a mpg one.

ive always heard normal gasoline has a stoichiometric ratio of 14.7:1, reformulated winter fuel runs between 14.3 and 14.4:1

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