Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: BridgeyBoy on 07 September 2012, 10:33:59

Title: Antoher fuel gauge question...
Post by: BridgeyBoy on 07 September 2012, 10:33:59
Hi all

I have a pre facelift 3.0 Elite auto estate. Runs and drives faultlessly but I’m not convinced about the accuracy of the fuel gauge / range readout. For instance, yesterday fuel range was down to 20 miles, put £20 worth of fuel in and range only went up to 55 miles. The fuel computer shows a fairly static average of around 20-21MPG (car is used mainly by the Mrs for short school runs etc so the MPG doesnt vary wildly).

By my calcs £20 worth of fuel = 3.25 gallons (at £1.35 per litre)
3.25 gallons @ average of 20 MPG = 65 miles range
+ original range of 20 miles = 85 miles

So, I reckon the range should show approx. 85 miles but it actually shows 55 miles ( a difference of minus 35%) and the fuel gauge only shows 10 litres (after putting 20 in)

Any thoughts? Is the gauge/range readout generally unreliable or could this be a sign of a fault somewhere?
Title: Re: Antoher fuel gauge question...
Post by: Entwood on 07 September 2012, 10:36:49
Fuel range depends on your driving characteristics over the last 10 miles or so... if you sit in top at 50 for  a while you can watch the rang RISE usually ...  then give it a blast in 3rd up a big hill ... and watch the range drop right off. It is an indication .. not a tablet of stone  :)

Fuel gauge sender is a simple float switch . so is affected by slope of car etc .. and is more affected the smaller the volume .. so is most inaccurate when nearly empty.

HTH
Title: Re: Antoher fuel gauge question...
Post by: TheBoy on 07 September 2012, 11:41:04
The MID is desperately inaccurate if you top up with small amounts, as initially, the system is thinking you haven't really filled it much, its just on a slope. It does eventually catch up, but buy the time it does, you've already filled it again.

Also, the system bases its calcs on the previous few miles of driving, and the amount it thinks is in the tank (taking into account the errors above), so that can impact it.
Title: Re: Antoher fuel gauge question...
Post by: 05omegav6 on 07 September 2012, 12:09:37
FWIW I get between 105 and 130 miles from £30/21.6 litres from my 3.2 manual :y

MID reckons 23 mpg, used mostly in town, and none too gently, although perhaps not quite in TBs league ::)
Title: Re: Antoher fuel gauge question...
Post by: omega3000 on 07 September 2012, 14:28:48
Thirsty old begger's around town those 3.0s , £20 a week i put in from the flashing light showing empty ... i think it showed 80 mile range last time for the £20  :(
Title: Re: Antoher fuel gauge question...
Post by: cam2502 on 07 September 2012, 15:00:14
I've wondered about this as well. I usually stick 30 quid in at a time, the display tells me my range is around 140 miles. Doesn't seem a lot for 30 sovs  :(
The average consumption last time I looked was 23 mpg
Title: Re: Antoher fuel gauge question...
Post by: TheBoy on 07 September 2012, 16:23:11
I've wondered about this as well. I usually stick 30 quid in at a time, the display tells me my range is around 140 miles. Doesn't seem a lot for 30 sovs  :(
The average consumption last time I looked was 23 mpg
Petrol is just over £6 a gallon, so getting around 5 gallons for £30. 5 x 23mpg = 115m (plus whatever was left in the tank)
Title: Re: Antoher fuel gauge question...
Post by: 05omegav6 on 07 September 2012, 17:21:30
I've wondered about this as well. I usually stick 30 quid in at a time, the display tells me my range is around 140 miles. Doesn't seem a lot for 30 sovs  :(
The average consumption last time I looked was 23 mpg
Petrol is just over £6 a gallon, so getting around 5 gallons for £30. 5 x 23mpg = 115m (plus whatever was left in the tank)
Reassuring, if a little disappointing :-\ Still, at least I know the MID is reasonably accurate :y