Why is the mpg on my car dropping daily?
31-10-2007, 05:31 PM
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Why is the mpg on my car dropping daily?
Over the last week the mpg has gradually reduced from 34.7 to 34! I've only had this car a week and a half...sob. Can anyone tell me why it may be doing this? It is a diesel Mondeo. My husband did check the tyre pressures at the weekend.
Minty xx
Minty xx
31-10-2007, 05:34 PM
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Yes maybe that's it. I have done a lot of very slow driving in traffic this week. Also I usually drive in flip flops, but have tried to turn over a new leaf this week and have been wearing trainers. They are heavier to drive in though.
Minty xx
Minty xx
31-10-2007, 05:36 PM
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34.7 to 34 is a fraction of a change. Going up one hill can make your average mpg on an entire tank (600 miles) drop more than that.
Seeing as you have only had the car a week and a half I would wait until you have driven it a bit more to get more of an idea of what average mpg it will do.
With steady driving though, you should see more than 34 on a diesel... Try driving a bit smoother - accellerate slower and slow down into corners/roundabouts more in advance using engine braking rather than the brake pedal.
On my Laguna diesel I see anywhere from 48mpg to 42mpg average on a tank. It all depends on how you drive, what roads you drive and probably the weather as well
Seeing as you have only had the car a week and a half I would wait until you have driven it a bit more to get more of an idea of what average mpg it will do.
With steady driving though, you should see more than 34 on a diesel... Try driving a bit smoother - accellerate slower and slow down into corners/roundabouts more in advance using engine braking rather than the brake pedal.
On my Laguna diesel I see anywhere from 48mpg to 42mpg average on a tank. It all depends on how you drive, what roads you drive and probably the weather as well
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31-10-2007, 06:13 PM
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ANything can make such a small change. Dont panic. If it was 50mpg to 30mpg over same distance etc then maybe something to worry about. But not that
31-10-2007, 08:16 PM
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i have an 04 plate mondeo 130 tdci and thats doing 41mpg and thats on the school run............i wouldnt even worry about a .7 fluctuation m8.....i get that if i boot it for a min or 2. 
its more like 8mpg if i drive it like a man though
01-11-2007, 12:05 PM
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Thanks for your answers. I haven't had a car that shows the mpg before so I thought that a drop of .7 was a lot. It still seems to be very little to the gallon for a newish car though, but maybe it isn't really run in or something yet.
Minty xx
Minty xx
01-11-2007, 01:00 PM
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Originally Posted by mintola
this week and have been wearing trainers. They are heavier to drive in though.
Driving in traffic you will not see good mpg - take it for a run somewhere, but reset the counter before you go...
01-11-2007, 02:00 PM
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Look, I know I'm a typical stereoptype kind of female driver, but that doesn't exactly make me a criminal (though I daresay some on here might disagree. 
).
I'm just trying to find out a bit more about the car I'm driving, that's all.
Minty xx
).I'm just trying to find out a bit more about the car I'm driving, that's all.
Minty xx
01-11-2007, 02:04 PM
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Originally Posted by JTECHSAFF
my saffs doing 30mpg 
@ 0.7 mpg difference though. 
Seriosly though, fill the car to the brim, do your normal driving week, then fill to the brim again and work it out manually. Repeat again, and youll probably find that it'll be pretty consistant for the next few runs. Providing you drive the same of course. Your always going to get a difference of a few mpg though.
01-11-2007, 02:09 PM
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Originally Posted by S1rst
Originally Posted by JTECHSAFF
my saffs doing 30mpg
@ 0.7 mpg difference though. Seriosly though, fill the car to the brim, do your normal driving week, then fill to the brim again and work it out manually. Repeat again, and youll probably find that it'll be pretty consistant for the next few runs. Providing you drive the same of course. Your always going to get a difference of a few mpg though.
)Minty xx
01-11-2007, 02:14 PM
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Originally Posted by mintola
Originally Posted by S1rst
Originally Posted by JTECHSAFF
my saffs doing 30mpg
@ 0.7 mpg difference though. Seriosly though, fill the car to the brim, do your normal driving week, then fill to the brim again and work it out manually. Repeat again, and youll probably find that it'll be pretty consistant for the next few runs. Providing you drive the same of course. Your always going to get a difference of a few mpg though.
)Minty xx
Just thought, you have reset the fuel computer when you bought it havnt you? Did you drive it back home a long way on the motorways when you bought it? All this will mean the mpg will drop gradually if your doing town driving. nothing to worry about anyway. Reset it and see what happens from week to week.
01-11-2007, 02:43 PM
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Originally Posted by S1rst
Originally Posted by mintola
Originally Posted by S1rst
Originally Posted by JTECHSAFF
my saffs doing 30mpg
@ 0.7 mpg difference though. Seriosly though, fill the car to the brim, do your normal driving week, then fill to the brim again and work it out manually. Repeat again, and youll probably find that it'll be pretty consistant for the next few runs. Providing you drive the same of course. Your always going to get a difference of a few mpg though.
)Minty xx
Just thought, you have reset the fuel computer when you bought it havnt you? Did you drive it back home a long way on the motorways when you bought it? All this will mean the mpg will drop gradually if your doing town driving. nothing to worry about anyway. Reset it and see what happens from week to week. Minty xx
01-11-2007, 02:48 PM
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Re: Why is the mpg on my car dropping daily?
Originally Posted by mintola
Over the last week the mpg has gradually reduced from 34.7 to 34! I've only had this car a week and a half...sob. Can anyone tell me why it may be doing this? It is a diesel Mondeo. My husband did check the tyre pressures at the weekend.
Minty xx
Minty xx
01-11-2007, 02:55 PM
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If this is a FORD.....
The software in the dash is calculating the average long term.
The more miles you do, the more accurate it will be over the total
distance since it was last reset.
As this figure approaches its internal count of 600 miles or is over that,
the figure will always be the average fuel economy over 600 miles.
Besides 0.7 miles is nothing
The software in the dash is calculating the average long term.
The more miles you do, the more accurate it will be over the total
distance since it was last reset.
As this figure approaches its internal count of 600 miles or is over that,
the figure will always be the average fuel economy over 600 miles.
Besides 0.7 miles is nothing
01-11-2007, 04:25 PM
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Originally Posted by Flux Capacitor
If this is a FORD.....
The software in the dash is calculating the average long term.
The more miles you do, the more accurate it will be over the total
distance since it was last reset.
As this figure approaches its internal count of 600 miles or is over that,
the figure will always be the average fuel economy over 600 miles.
Besides 0.7 miles is nothing
The software in the dash is calculating the average long term.
The more miles you do, the more accurate it will be over the total
distance since it was last reset.
As this figure approaches its internal count of 600 miles or is over that,
the figure will always be the average fuel economy over 600 miles.
Besides 0.7 miles is nothing
Minty xx
01-11-2007, 04:39 PM
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Originally Posted by littlebrownbike
On a serious note though, I do think its a bit harsh the way everyone keeps ripping in to him. Not everyone is a car buff and we're all here to learn (except me I know everything).
Still a stupid fucking question mind you.
Still a stupid fucking question mind you.
