Does gas mileage get noticably worse in cold weather?

I have a 6s base, the only major mods are coolant bypass and airbox mod. I got about 350 miles per tank driving from work to home and back until the temperatures just hit rock bottom. Now I seem to be getting around 300 miles per tank, if that. I think last time I got like 280 miles off of 16 gallons of gas. Could this just be because the highway is more like city, as people are going slower, or what? Could this be an issue? Or, it might be all the gas stations are lieing and saying I'm putting more gas in then I really am.

Help, gas is too expensive for this to be happening.

 

Cold air is denser, thus results in a bit more power. More power equals poorer gas mileage. On the mechanical side, do you possibly have a leaking injector, or a leaking fuel line?

David

 

well if you have a airbox mod, it will hurt your mileage even more. I have the 2.3 automatic. I have a short air intake on and am getting 400-420 miles per tank in these 10 degree temps. So I believe that works out 23-24.so you may have a problem. However, in the summer, I get 480-500 miles per tank.

 

When I say tank, I usually fill up with about 16 gallons (I try and avoid running it dry).

How would I find a leaking injector or fuel line? I haven't seen any puddles under my car.

 

Um...the airbox mod shouldn't hurt gas mileage, if anyhing it should improve it a bit (less restriction = improved airflow and thus better efficiency, thus better mileage). I will agree with what david said, and the only sure fire way i know of to find out if you have either of those is to take the car to a mechanic (ie. someone with a greater knowledge of the internal workings of the engine than myself). as for the mileage...well i think the best I've been able to get out of my 6cyl is around 350mi from 16.7 gal so I'm not really one to talk about efficiency XD.

-Cameron Keffer

 

It's not the same engine, but my V6 is getting around 17.3 MPG in the winter. You're probably around the right area.

 

if it is a mod that is similiar to an short ram intake, it can hurt mileage. I have been told this a few times. A SRI can make a car use more power at lower RPM's. It was something along those lines. It is only a theory. If if is a CAI, it tends only affect a higher RPM range. I am having a hard time putting this into words... But I believe this theory. Can anyone clear this up?

 

The mod is hard to compare to either of those, since it is still more restrictive than both. With said mod you are simply removing certain parts of the air box that are there largely to dampen sound as a result some restrictions on airflow are eliminated and air is drawn in from the driver side wheel well (as in a CAI) so there is less heatsoak than with a SRI. As for any of those things causing a drop in mileage, I've never seen anything other than anecdotal evidence to support the view. If you have a link to hard facts, post it up, I'd be interrested to read it.

-Cameron Keffer

 

my mazda 6 2007 gets only like 270-310 on a full tank....is that normal?

 

That would depend on several things:
A) Do you have the 3.0L V6 or the 2.3L I4? If it's the V6, then it's not unheard of, defenitely low, but not unheard of.
B) Are you a "spriited" driver? If you are liberal with the go pedal then and you have the 6cyl then this is defenitely in the realm of feasability.
C) Do you use the recomended grade of fuel? 93 octane in the NA (naturaly aspirated) versions of this car is simply not needed and can even make the engine run less eficiently as the higher octane gasses require more energy for ignition . Thus if you're using the expensive gas, you could actually be hurting the performance and mileage of ur car.

-Cameron Keffer