Sudden and dramatic drop in fuel economy

[switchmitch]

Look at your home electricity bill! Air Conditioning uses a lot of energy.
(On the plus side you can turn of your water heater - hot water comes our of the cold tap!)

What does home electric bill have to do with the gas engine of a truck?
As noted previously in multiple posts, the ratio of gas engine use to electric motor use has been the same
Plus the weather hasn't gone above 70 degrees here so heat is whole irrelevant.

The problem is the gas engine economy when it is active, not the overall fuel economy of the entries system

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[grumpyunk]

Is the mpg noted based on the 'calculated' by the built-in software, or is it a manual divide miles/gallons ?
If the former, a reset by disconnecting the battery may work to get it back to normal. If the latter, then checking for leaks would be logical, and checking for any OBD-II codes would make sense. This is assuming that you do not have people who are helping their self to the contents of your gas tank.
tom

 

[GPSMan]

I have a hybrid Maverick. Have had it since march.
All of a sudden today the fuel economy plummeted, specifically when the gas engine would kick on (relative to previously)
Even rolling through a parking lot of accelerating very slowly the instant MPG would read single digits, like 3-7mpg. Previously it would have been much higher. (power usage gauge would be reading like 5-10% power, just out of the green zone.

The electric motor still kicks on as expected but the gas engine never really got higher than 20mpg and that was momentary.

This was all around town driving on flat roads, drive I previously would have gotten 40+ and over 50+ MPG were well down in the 20's and 30's

What could be going on?

Don't get worried over one day or one tank. There's 100 reasons for this. And you'll never know for sure.

Assuming you don't see or smell gas leaking Come Back and tell us how the truck is doing in a few weeks.

 

[WJOHNM]

This is a joke right, move to warn

Heat. Hybrid batteries need to be forced cooled over Summer temperatures. Just one of the unexpected Maverick hybrid issues. Not a wide spread issue for other hybrids. It will go back to normal once high temperatures are below 90. Park in shade. Avoid hot streets, black asphalt, driving after 2pm. Etc.

Heat. Hybrid batteries need to be forced cooled over Summer temperatures. Just one of the unexpected Maverick hybrid issues. Not a wide spread issue for other hybrids. It will go back to normal once high temperatures are below 90. Park in shade. Avoid hot streets, black asphalt, driving after 2pm. Etc.

This is a joke right, stay off paved roads use dirt roads and trails if in shade , only drive at night if hot dont drive, move to colder climate if its hot out have vehicle towed to better climate, plant trees to park under by your house. Or just sell the vehicle and get a Eco boost, you'll make money on the sale and you can drive anywhere any time. Sorry couldn't resist

 

[rivermaverick]

What does home electric bill have to do with the gas engine of a truck?
As noted previously in multiple posts, the ratio of gas engine use to electric motor use has been the same
Plus the weather hasn't gone above 70 degrees here so heat is whole irrelevant.

The problem is the gas engine economy when it is active, not the overall fuel economy of the entries system

Sorry, I was following up on the posts blaming the AC, if your temperature is 70° then the problem is not the AC.
It will be 119° here today, it was 88° at 5am when I walked the dog.

 

[MakinDoForNow]

What does home electric bill have to do with the gas engine of a truck?
As noted previously in multiple posts, the ratio of gas engine use to electric motor use has been the same
Plus the weather hasn't gone above 70 degrees here so heat is whole irrelevant.

The problem is the gas engine economy when it is active, not the overall fuel economy of the entries system

I read that you are referring to the "instant mpg readings" being reduced from what you remember seeing previously! Nothing is to be worried about as you may be accelerating slightly faster today than on previously. Your route may be slightly different than previously also. I have a 14 mile trip I take frequently that trip meter reports about 7-8 mpg difference in north to south direction than south to north... Also if relative humidity is really high I will get more mpg than when it is lower (possibly a vote for the air intake humidifier/cooler we diy'd in the 1960's). I will usually drive the 14 miles in slippery cruise at 40 mpg and temp difference of 20°F can be several mpg

 

[TedTX]

Not joking about my posts, those tactics work, may not be practical to very many Maverick drivers. The common core is heat being radiated from below the truck into the battery pack BELOW the truck. The use of the Truck in heat isn’t a large as having to cool the battery once in operation. That first X miles are needed to strongly cool pack to below operating temperature are killing gas mileage.
I image Ford adding a radiant type shield below the battery and likely change the thermal characteristics of the packaging to make it more even year round. The batteries are very dense and changing temperature takes time based in thermal mass. That is why those silly suggestions work. It keeps the batteries near average temperature for the battery and not soaking up heat energies from below.

 

[Dom94]

Any resolve to this issue? I'm having the same exact problem currently on my Maverick Hybrid I purchased new three weeks ago. First two and a half weeks I was averaging 40-50 mpg, now I'm struggling to get mid 20s. Driving through a parking lot at 5 mph I was able to get super inflated numbers as high as 116 mpg, doing that same test now I'm getting single digit mpg.

 

[colinl]

Any resolve to this issue? I'm having the same exact problem currently on my Maverick Hybrid I purchased new three weeks ago. First two and a half weeks I was averaging 40-50 mpg, now I'm struggling to get mid 20s. Driving through a parking lot at 5 mph I was able to get super inflated numbers as high as 116 mpg, doing that same test now I'm getting single digit mpg.

Stop looking at the instant fuel economy and even the trip meter.

Pump a full tank of gas and make a note of the odometer reading. Then just drive normally on any screen that doesn't show mpg, and wait until the tank is empty. Calculate your mileage by hand.

I bet there is no issue other than looking at an inaccurate and irrelevant instant mpg far too often.

 

[colinl]

This explains so much. Thank you to whoever included the YouTube video

The video was linked by the person who made it, Sam from Test Driven TV. Subscribe, he's one of the best.

 

[SteveDel]

Had the same happen to me today. While in hybrid mode trip meter shows single digits mpg. Nothing to do with change in driving habits or weather. Will reset trip meter and see if that resolved it.
Agree it was alarming to see 37 mpg drop to 8,

 

[Bittle35]

I noticed a drop in my hybrid mpg after getting the PCM updated..

 

[CurtisB]

May I suggest something. If you have never driven a hybrid before, you will get mixed up with dashboard readings and the like. Ignore the readings until you have gone through at least one full tank of gas. Your computer is trying to adjust to the type of driving you do. So, sometimes the dashboard will read 47mpg and as you drive another 2 miles and it changes 32mpg. Thats the computer trying to calculate. Your have a new car, and it's trying to get used to you.

Get through at least one full tank, divide the number of miles driven by how may gallons it took to fill up. Then before you reset the gauge, look and see how close you will be to. Give it time. Trust me, been there done that. We called it in the Prius community "Dashboard gas reader" syndrome.

 

[CurtisB]

I noticed a drop in my hybrid mpg after getting the PCM updated..

This also happened to me in my Prius. The computer will take some time to adjust after the update. It should get back to normal.

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