Is The Dashboard Figures Accurate? (Miles Left To Empty Tank)

[RiDER07]

I was just wondering, where it says xxx miles to empty tank. Is that an accurate value?

Thanks in advance

[Dee_82]

yes and no, if your driving style is consistent and you've not reset everything (trip miles is fine to reset)

if your erratic and you constantly reset the millage / ECU then no its not, mine started with a full tank on 400 miles after I reset the ECU! 300 miles later its at 250 to go.

if your worried about filling up, just wait till the light comes on an fill it, don't push it passed the red and you wont have a problem

[RiDER07]

Okay put it this way. My driving style is very consistent and I average around 31 MPG pretty much all the time. I have never reset the ECU, I don't even know how to do that in the first place lol.

I really want to know if the dashboard is accurate and how much miles a full tank can give me.

[Dee_82]

probably is fairly accurate, its never going to be perfect though, if you kick the balls out of it, its going to drop like a rock, if you push you mpg up to 35 then then you will see it drop slower or even increase.

as I said, it just depends, the best gauge is the fuel gauge

[TomsFocus]

Not overly accurate... Mine said I was only gonna get 400 miles when I filled up... 450 miles later I've still got 200 miles to go according to the range. :D

It gets more accurate towards the bottom of the gauge though, assuming you're driving fairly consistently. And it'll over-estimate as well, so tell you theres '0' miles to go when theres probably about 50! I wouldn't push it past the 0 though, did twice in my old Vectra and that was fine...but doesn't mean it'll be the same with the Focus lol.

[mjt]

Obviously the range is calculated based on the current average fuel consumption and when you consider the number of variables involved it's quite amazing that it's as accurate as it is. For example the fuel consumed is measured from the injector opening times but this is dependant upon the fuel rail pressure and the temperature of the fuel (warmer fuel being less dense). The distance travelled is affected by the amount of tyre wear and the "slippage" that occurs between tyre and road which is affected by the grippiness of the tyre (which depends upon the hardness of the tyre compound) and the road surface (more slippage in the wet, for example).

[Figgis41]

I did a trip from Hull to Brighton down the M1 route with the wife,,, mine was fairly accurate to within say 30-40 miles or so,,, i dont know what its like on a full tank as i never fill the tank,,, why carry around the extra weight and burn more fuel ?
But as mentioned you also have the gauge on the dash and the low warning light to remind you where its at.

[jg321]

Mine said 11 miles remaining the other day and I filled it with 51.5 litres! Given it's a 53 litre tank I'd say this is pretty accurate, if not a little conservative. Was quite concerned about running out of fuel tbh, especially being a diesel.

[Figgis41]

half a tank is around 6 gallons going on Jon's figures,, car gave me around 50-55 mpg down the M1 route.
trip compy said around 310 miles for the half tank and the distance from Hull to Brighton down the M1 route was around 280 miles with 2 stops at the service stations and the avarage was 50-55 mpg and i was left with around 40ish on the trip computer miles to refill.

im not a fuel !Removed! or anything like that, but just remember noticing it and taking mental note out of curiosity as its the longest single trip the car has done,,, plus my mate is scottish and is a fuel !Removed!,,, drives at 63 every time hes on the motorway and is always checking his milage.
so its not exact but close would you not say.

[TomsFocus]

Mine said 11 miles remaining the other day and I filled it with 51.5 litres! Given it's a 53 litre tank I'd say this is pretty accurate, if not a little conservative. Was quite concerned about running out of fuel tbh, especially being a diesel.

Blimey, that is fairly accurate then! Though you can probably get over 10 miles to a litre and a half, if you hit a hill or sharp corner could end up with no fuel at the pickup. Maybe I wont push it so far then haha.

[troy45]

Mine never seems to be accurate, always says in the region of 300 or so miles to go after every fill-up but that's way too optimistic! That goes into the 400's if I've had to disconnect the cluster or battery for some reason.

That's pretty much the story after every fill-up, though I always reset all trip values & averages etc. when I fill up. May try just resetting the trip and see what that does.

For the Focus diesels, there could be a concern with fuel pumps burning out if you were to run fully empty - so Ford may well engineer the system to read low so you always have some fuel left, or even go as far as engineering in a misfire once the fuel gets to a certain minimum level.

[moggyman]

Hi there, I frequently do a 700 mile trip to france and having had both mk1 and now 2 diesels I've found the mk2 readout to be pretty accurate and consistant providing you don't keep resetting it during a trip. the mk1 readout would go up or down depending on the instantaneous consumption reading whereas the mk2 readout never increases no matter how economically you drive it just knocks the miles off slower ( ie 1 mile knocked off when in reality 1.3 miles have been covered.)

I find on these trips I usually average 54 to 59mpg from the 1.8 tdci depending on load with a worst of 49.9 very heavily loaded with tools, ladders on the roof and bikes on the back.

[vince_13]

Not overly accurate... Mine said I was only gonna get 400 miles when I filled up... 450 miles later I've still got 200 miles to go according to the range. :D

It gets more accurate towards the bottom of the gauge though, assuming you're driving fairly consistently. And it'll over-estimate as well, so tell you theres '0' miles to go when theres probably about 50! I wouldn't push it past the 0 though, did twice in my old Vectra and that was fine...but doesn't mean it'll be the same with the Focus lol.

id have to disagree there, i had mine drop 25miles over night

i parked it up with 50miles (and the light came on) i knew the petrol station was 8 miles away, next day got in to go to work and boom...25miles until empty,

i thought never mind petrol station is only a few miles away .... i got there with 11 miles left in the tank

needless to say i never go below 40 now

[TomsFocus]

My red light still isn't on...but the gauge is perilously close to empty and I've done 570 miles to this tank. Range says 66 miles to go. Petrol station is about 15 miles away so I hope the miles don't drop off over night! :P

[TomsFocus]

Well, filled up today on dead on 600 miles...

Range said 44 miles to go at the petrol station. Only got 46.6 litres in so was still about 5 litres to go!!

Average mpg read 57.4. Calculated mpg 58.58.

After filling up range read 625 miles, which seems like a reasonable figure.

[Daniel Rodentburg]

I have a full report on fuel within the last week

 

Saturday (9/7/16)

10:07am (35 mls droped down to 33 when I started the engine!)

12:32pm (28 mls went up to 34 like it does)

4:20pm (107.7p filled up £5 up from 26 mls to 62 mls

 

Sunday (10/7/16)

Didn't drive that day, had a stay at home

 

Monday (11/7/16)

55 mls up 1 mile to 56

Went to fill up at the garage again as the fuel consitetly fell to 37 when it said 53mls when driving, so I asked my local garage whats wrong with it so now I have a 16 model cmax

[Neon Tetra]

I used to own a Focus 1.8 TDCi. The fuel warning light always came on when the trip computer said there was 50 miles left to go before refill. It was completely predictable. I felt I could trust it  over the four years I owned the car. My Mondeo mark 4 has the warning light coming on anything between 120 and 80 miles left before refill. I honestly dont know where the heck I am with it. I suspect either the warning light or the trip computer is faulty but I always refill as soon as possible when the light comes on just in case.  It just annoys me I cannot accurately predict when I need to refill. I sometimes think I should just trust the fuel gauge and ignore the warning light but what if the gauge is wrong?  Is there any way the accuracy of the fuel warning light can be checked? If I could sort that out first of all, I could use a process of elimination to work out what the problem is, if indeed there is a problem at all.

[mjt]

10 hours ago, Neon Tetra said:

I sometimes think I should just trust the fuel gauge and ignore the warning light but what if the gauge is wrong?

They both operate from the same sensor so if one is wrong they'll both be. As for the variability of your readings I'd refer you to my post earlier in this thread (dated Oct 12 2014).

[spurswes]

When my car was in the garage for something,one of the mechanics took it out on the road and it ran out of petrol with 30 mls remaining . Why does it say there's fuel in the tank when there actually isn't??

[TomsFocus]

Crikey, nothing like digging up an old thread lol.

I find the Fiesta range is pretty poor, it's fine until it gets to the 50 miles red light, but then it just keeps saying there's between 25-50 miles left (goes up and down)...it did this for about 70 miles on the last tank, and when I did fill up (on like 25 miles iirc) I got more petrol in than the tank size so must've been extremely low!!

However, the Focus is the other way...even if I keep pushing it for as long as I dare still never get more than 50 litres in the 53 litre tank.

[Hummingbird83]

I'm having similar issues with my ford focus ecoboost 1.0 titanium . The miles on the dashboard are falling dramatically. It falls by 3 miles approx to every 1.5 miles on the trip computer. I've had it looked at in service and they said it's fine. I'm hoping there's nothing wrong with the car and it's just an inaccurate float in the tank. Either way, I appear to be filling up more regularly. My MPG is currently 36.0 based on 9700 miles.