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17 Ecoboost drop in MPG after ford performance tune.

7961 Views 11 Replies 9 Participants Last post by  kadconner1122
I was averaging 18.4 in the city with mildly aggressive driving (AUTO) and after the tune install I'm in the neighborhood of 14-15. No check engine lights or anything of that nature, but from reading all of the comments I don't think this is normal. Any suggestions?
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Are you driving the same way you were before the tune? I know that every time I upgrade something, I'm more likely to mash down the gas pedal to see how it works and have fun with it.
Yeah, I've gone through about 3 tanks now and the MPG is trash. I've tried resetting the computer and driving like a grandma and it's still terrible for city driving with few lights. I was driving aggressive before and having fun in between stop lights and easily hitting 18.4-6 and now I'm lucky to be at 15.6 lol. Noooooooooooo idea what the hell changed, but it's definitely not a lead foot.
My 17 Ecoboost Mustang has the FP tune and I didn't see any change in the gas mileage. I was getting 27 to 29 mpg on my commute before and I still am. The only time you should see any drop in mileage is when you are under boost.

FWIW, I have been driving turbo 4s continiously since 1985 and all of those cars were tuned and all got the same or better mileage after tuning.

Dave
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I bet you have a leak in the air box install. My ford tuned 17 is getting mid 24 at 85mph. 27 at 75 mph.
Also depending on where you live the winter months are horrible on mpgs.. here is great information on the subject



Fuel Economy in Cold Weather

Cold weather and winter driving conditions can reduce your fuel economy significantly.

Fuel economy tests show that, in short-trip city driving, a conventional gasoline car's gas mileage is about 12% lower at 20°F than it would be at 77°F. It can drop as much as 22% for very short trips (3 to 4 miles).

The effect on hybrids is worse. Their fuel economy can drop about 31% to 34% under these conditions.

Why is winter fuel economy lower?
Cold weather affects your vehicle in more ways than you might expect:

  • Engine and transmission friction increases in cold temperatures due to cold engine oil and other drive-line fluids.
  • It takes longer for your engine to reach its most fuel-efficient temperature. This affects shorter trips more, since your car spends more of your trip at less-than-optimal temperatures.
  • Heated seats, window defrosters, and heater fans use additional power.
  • Warming up your vehicle before you start your trip lowers your fuel economy—idling gets 0 miles per gallon.
  • Colder air is denser, increasing aerodynamic drag on your vehicle, especially at highway speeds.
  • Tire pressure decreases in colder temperatures, increasing rolling resistance.
  • Winter grades of gasoline can have slightly less energy per gallon than summer blends.
  • Battery performance decreases in cold weather, making it harder for your alternator to keep your battery charged. This also affects the performance of the regenerative braking system on hybrids.
In severe winter weather, your mpg can drop even further.

  • Icy or snow-covered roads decrease your tires' grip on the road, wasting energy.
  • Safe driving speeds on slick roads can be much lower than normal, further reducing fuel economy, especially at speeds below 30 to 40 mph.
  • Using four-wheel drive uses more fuel.
What can I do to improve my fuel economy in cold weather?
You may not be able to completely mitigate cold weather's effect on your fuel economy, but you can do some simple things to help your gas mileage:


  • Park your car in a warmer place, such as your garage, to increase the initial temperature of your engine and cabin.
  • Combine trips when possible so that you drive less often with a cold engine.
  • Minimize idling your car to warm it up. Most manufacturers recommend driving off gently after about 30 seconds. The engine will warm up faster being driven, which will allow the heat to turn on sooner, decrease your fuel costs, and reduce emissions.
  • Don't use seat warmers or defrosters more than necessary.
  • Check your tire pressure regularly.
  • Use the type of oil recommended by your manufacturer for cold weather driving.
  • Remove accessories that increase wind resistance, like roof racks, when not in use.
  • If you drive a plug-in hybrid or electric vehicle, preheating the cabin while plugged into the charger can extend your vehicle's range.
  • If you drive a plug-in hybrid or electric vehicle, using the seat warmers instead of the cabin heater can save energy and extend range.
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How often do you guys check your tire pressure? This is my first car with TPMS, so I'm checking every time I drive it, and that's helping to remind me to put more air in the tires during cold spells. Not only does that help mpg, I like the way it handles better with firmer tires.
How often do you guys check your tire pressure?
Weekly. Since my wife's TPMS doesn't display the pressure, just the "!" on the dash, I put a pressure gauge on hers once a week. While doing hers, I do mine and my CR-V which doesn't have TPMS. With the temps fluctuating as much as they are now it's a good idea to check 'em often.
How often do you guys check your tire pressure?
I'll admit I'm lazy on this. Since our TPMS shows pressure, I don't actually check often. At least not on purpose. I do end up checking them a couple of times a month at Autocross, since I'm checking the racing rubber...
Since the TPMS pressure displayed is within 1/2 a psi of my gauge I don't check with a gauge unless I need to add air.

Dave
Something is definitely seems wrong....they either made a mistake with tuning, or you have some kind of boost leak. Are you able to see what your gauge readings are for your air/fuel ratio and/or boost levels during acceleration? Can you tell if the car pulls harder after the tune? Have you done any other mods?
Yeah, I've gone through about 3 tanks now and the MPG is trash. I've tried resetting the computer and driving like a grandma and it's still terrible for city driving with few lights. I was driving aggressive before and having fun in between stop lights and easily hitting 18.4-6 and now I'm lucky to be at 15.6 lol. Noooooooooooo idea what the hell changed, but it's definitely not a lead foot.
hey man, Im having the same issue, for anyone looking into this now and having this issue still 5 years later... If your running the Cobb Stage 1 OTS tune, they have multiple settings for the tune... You can toggle which mode it is in by using cancel and up, down on the steering wheel. (cruise control side) FROM FACTORY its left on level 1, OR open turbo.. open boost whatever u wanna call it. It basically means the cars always finding a way to build boost to a max no matter what. You have to toggle it into the the number 5, or ECO mode. there are other modes but you would have to look at those i dont know them off the top of my head. You can find them here in forums however. Hope this helped!
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