What happened to my gas mileage??

[Sny714]

I first bought this cobra last april with 95% of the mods listed in the sig. If I remember correctly, I was getting probably around 220-230 miles to a tank. It seems that the past 2-3 months have been a steady decline. Slowly, I would only get 200 to a tank then 185-190 and now today I managed to get 171 miles to a tank!! Thats around 12mpg. This is getting ridiculous and especially at $3.50 a gallon. My job is 3 miles away and its all streets, no highway, so Im sure that doesnt help it. My driving habits pretty much stayed the same from when I bought the car, in fact I might even drive easier now. So what gives?

Dont get me wrong, I didnt buy the cobra to get 27mpg, but its weird how this seemed to happen with my notchback to. With the notch there was a steady decline in mpg over time. BTW, the car has 10-15k on the motor and 47k on drivetrain. Does the fuel filter need to be changed? I changed my FF on the notch and it slighly made things better but not much.

 

[V6&V8SHO]

Dont know the weather round there but doesnt cold short drives result in low mpgs

 

[brkntrxn]

Like Jon said, weather is my first thought. When the temps dip, gas mileage goes to crap.... especially on short trips like you are describing.

 

[VirtualSVT]

My gas mileage dropped to shit with the cold weather. I drive a mile each way to work so my car barely warms up.

I would get almost 250 a tank now its down to 180-190 with the highs being in the 30's.

 

[01SVTSnake]

i used to get about 175 miles a tank in the summer filling at the 1/4 mark. now im at the 115-130 mark. I do 90% city driving. Today i got to 171 but i took a trip into philly which was all highway. Also i believe the oil companies put different additives in the gas come winter time as well.

 

[olgreydog7]

3 miles to work? Ride a freakin' bike! But seriously, when you fill up, fill up ALL the way. If gas spills out, the gromet that goes around the filler neck and into the tank may have failed. It happened to me, so every time I took a hard corner, it spilled out. Plus, as you are parked, it is evaporating out. It's kinda a pain to swap out, cause you have to drop the tank. If that's it, I'll look up the part number for you. Though, I think it might have changed. It's about $20. Check your air filter and your fuel filter. Look for any other fuel leaks too.

 

[RedRocketMike]

Winter gas formula cuts your mileage down.

 

[StevesBuddyAntz]

You bought a V8

 

[Sny714]

Yea i heard about the additives before but I didnt think it would be this bad. Plus my car is warmed up every morning for about 10 minutes before I go to work, so the car is never driven in the cold without running at normal temp.

 

[Sny714]

You bought a V8

Thats not the point and I knew I would get a response like this from at least one person. If you read the 1st post I said Im not expecting great gas mileage, im just wondering why the drop off in the past months.

 

[Bizarro]

You bought a V8

You funny guy, you...


.

 

[01 Venom]

I am gonna go with the cold theory myself, the car takes a really long time to heat up in weather like this. Winter fuel might have something to do with it.

Few quick and easy things
1) clean your air filter
2) Change the fuel filter (never hurts)
3) Tune up, new plugs

 

[Quadcammer]

Yea i heard about the additives before but I didnt think it would be this bad. Plus my car is warmed up every morning for about 10 minutes before I go to work, so the car is never driven in the cold without running at normal temp.

well, idling your car for 10 minutes certainly isn't going to help your gas mileage. At idle, you are getting 0 mpg.

 

[01 Venom]

well, idling your car for 10 minutes certainly isn't going to help your gas mileage. At idle, you are getting 0 mpg.

:lol1:

That is true

 

[JedWele]

It's just the cold weather it happens to every car, my work is pretty close and even in my SVO gas mileage has decreased alot. The car will spend much more time in open loop with it being cold out and running richer. Plus as mentioned a lot more idle time as your warming up the car etc.

 

[SgtMike]

Mine has gone down too

I am getting 190ish per tank now compared to 220-230 in the summer.

 

['95yellowGT]

You bought a V8

jackass

 

[3B99SVT]

2) Change the fuel filter (never hurts)

Last time I changed my fuel filter, it did hurt! :bash: Stupid thing is difficult to get to w/the IRS and big hands!!!

Just for grins :rolling:

 

[01 Venom]

ya it is a bit of a pain in the ass

 

[SnakeBit]

My job is 3 miles away and its all streets, no highway, so Im sure that doesnt help it. My driving habits pretty much stayed the same from when I bought the car, in fact I might even drive easier now.

Maybe it's due to a buildup of carbon. Put it on a dyno for a few runs and I'll bet the ground behind your tailpipes will be coated black. These engines need to be driven hard from time to time to "blow out the cobwebs". I'm sure that winter gas isn't helping in that area either. You could also pull, clean and regap your plugs.

A tune might also help (didn't see it in your sig).