MPG claims + petrol v. diesel

[invalid]

Before using RED, read= Excise Notice 75: fuel for road vehicles - Publications - GOV.UK :scared:

 

[Deleted member 48021]

I am going to upset you kiwi, and all the rest with high fuel consumption..........

Many thanks to all who responded to this post - interesting comments and much appreciated - all except 'pughed2' who succeeded in "really upsetting (me)" with his 43mpg.:rolleyes2: I'm slowly climbing out of severe depression after that but now, when I'm in the slow lane struggling with 50mph and a fiat ducato passes me in the outside and doing 70mph, I can't even pretend he's getting a really low mpg!!
Ah well, I still thoroughly enjoy the wonderful opportunities WildCamping POI's give me, mulling over poor performance and low mpg whilst tucked into some beautiful inconspicuous spot with no-one about, - just me, the van and an empty fuel tank - "happiness is..."

 

[RichardHelen262]

Can you really put a price on fun ? Just fill it up and go off and enjoy yourself, and stop working out how many miles you are getting to the gallon.
Concentrate on how many smiles ������ you get to the gallon

 

[colinm]

On our 2.3L diesel Campscout (L4 H3 x2/50 PVC) we can reacon on getting around 30mpg on average, driving on motorway at 70mph(true, 74mph indicated) this will drop to around 25mpg, trundling around the lanes at low speed and it will be doing around 35mpg.
Previous van was a 1.9L petrol T25 VW PVC, we could usually expect high 20s in this. So your mpg would be fairly good for that van as far as I'm concerned.

 

[Mick H]

People have always tried to compare mpg, and always will, no doubt, but, IT IS UNLIKELY THAT ANY ARE ABLE TO CHECK WITH ACCURACY!

I say this because there are too many variables that enter into calculations. It has already been posted about the inaccuracies of speedo trip meters, but it doesn't end there.

You don't even know how much fuel you have put in, only how much you have paid for. Pumps are notoriously inaccurate, and in order to avoid problems with weight and measures, are normally set to deliver slightly more than they show. They are spot checked, on a regular basis, and it isn't unknown for the same pump to deliver a different quantity, when checked first thing in a morning, to later, the same day.

Because a fuel expands/contracts, according to temperature, again, you wouldn't know how this affected your calculations.

Even filling tankful to tankful, can't be relied upon, because of the camber effect.

Wind speed is variable, and can have a dramatic effect on fuel consumption.

These are probably the main factors that affect calculations, but there are others.

To sum up, if you can't be sure how much fuel you have put in, or what mileage you have covered, how can you possibly check mpg, with any accuracy.

Just curious, why hasn't anyone commented ref my above post on this issue?

 

[2cv]

Just curious, why hasn't anyone commented ref my above post on this issue?

It is possible to do it quite accurately.
Firstly it needs to be done over a period of time, so that on average wind will be neutral and overall filling inaccuracies become negligable,. Ideally at least a year to take account of seasonal variations and to give average usage.
Secondly to take account of guage inaccuracy a sat nav needs to be employed to compare actual and recorded mileages.
Using these methods should, I think, give a reasonably accurate result (for what it's worth)

Using the above methods I measured the mpg on a BX I once had over a period of years (sad I know!). It was interesting to note the lower mpg achieved in winter months each year, presumably due to extra choke needed.

On my 2.0 Trafic I achieve 33mpg.

 

[Robmac]

Just curious, why hasn't anyone commented ref my above post on this issue?

Like most things in life, you can only work with the available parameters, which will give you a reasonable idea, if not 100% accurate.

To be honest, the only time I care about MPG is if it dips sharply for no apparent reason.

 

[kris]

I am going to upset you kiwi, and all the rest with high fuel consumption..........

Many thanks to all who responded to this post - interesting comments and much appreciated - all except 'pughed2' who succeeded in "really upsetting (me)" with his 43mpg.:rolleyes2: I'm slowly climbing out of severe depression after that but now, when I'm in the slow lane struggling with 50mph and a fiat ducato passes me in the outside and doing 70mph, I can't even pretend he's getting a really low mpg!!
Ah well, I still thoroughly enjoy the wonderful opportunities WildCamping POI's give me, mulling over poor performance and low mpg whilst tucked into some beautiful inconspicuous spot with no-one about, - just me, the van and an empty fuel tank - "happiness is..."

Wouldnt worry about that figure-I have a 2007 Relay with 2.2 Tranny engine weighing in at 2780 kg and how ever I drive it am happy to get 35mpg.People quote around 40 mpg -maybe possible at 40mph but if you get 35 mpg you are doing OK!

 

[Mick H]

It is possible to do it quite accurately.
Firstly it needs to be done over a period of time, so that on average wind will be neutral and overall filling inaccuracies become negligable,. Ideally at least a year to take account of seasonal variations and to give average usage.
Secondly to take account of guage inaccuracy a sat nav needs to be employed to compare actual and recorded mileages.
Using these methods should, I think, give a reasonably accurate result (for what it's worth)

Using the above methods I measured the mpg on a BX I once had over a period of years (sad I know!). It was interesting to note the lower mpg achieved in winter months each year, presumably due to extra choke needed.

On my 2.0 Trafic I achieve 33mpg.

The old addage applies here, If you put rubbish in, then you get ................

 

[Mick H]

Like most things in life, you can only work with the available parameters, which will give you a reasonable idea, if not 100% accurate.

To be honest, the only time I care about MPG is if it dips sharply for no apparent reason.

The point I tried to make was that you can't be at all certain if it IS a reasonable idea, let alone be anywhere near accurate!

 

[Robmac]

The point I tried to make was that you can't be at all certain if it IS a reasonable idea, let alone be anywhere near accurate!

Surely consistency over several trips counts for something. I reckon I get just over 30 MPG, every time I have bothered to check, it is there or thereabouts.

 

[ricc]

even if the mpg figures we each obtain arnt scientifically precise , they have value to us, taken over a period of years in all sorts of conditions and all the other variables they can give us a reasonable idea of what we as individualscan do to maximise the distance we get from each gallon of fuel, it can even give indications of which vehicles are more economical. precise ,accurate numbers that can be compared with somebody elses numbers arnt actually necessary

in short i dont give a stuff whether im actually getting 34 or 36 to the gallon as long as its the highest mpg i can get , consistant with getting me and my load of baggage where i want to go in a reasonable time frame.

 

[Fazerloz]

I keep an eye on my mpg as a indictor to the running of the van. Anything between 26- 31 I just put down to variables. if it were to suddenly drop to below 25 I would think something needs attention. Fiat 2.3 120 multijet PVC.

 

[Deleted member 919]

heres mine 39 fills in just over a year.and 19.000 kilometers
Fuel Consumption details for 3000cc 2007 hymer b504cl on a Fiat Ducato Chassis owned by rebbyvid with average MPG of 36.80

Average number of days between refuelling stops: 13
Average Cost per litre: £1.163
Average Cost per Gallon: £5.28
Miles Per Litre: 8.08
Cost per Mile: £0.14

 

[Deleted member 52918]

If anyone wants to know the true meaning of fear, try driving a 1922 Rover tugging a vintage caravan between 20-30mph in the slow lane of a motorway.
For those interested in BIO I have put a link to my site for your information.
http://alifife.co.uk/wasteoilwestdevon/index.htm
:drive:[/QUOTE

it's a very bad idea, it's best to stick to A & B roads with a vehicle that slow!!

Phill

Ps., there is no slow lane on a motorway!

 

[Mick H]

Underground storage tanks ARE affected by temperature changes, even if these are not so great, also your vehicles tank IS definitely affected.

The camber effect IS NOT negated, to any significant degree, in the way that you have suggested.

Wind speed could average out, but certainly can't be taken for granted! It could be one of the reasons that calculations vary.

Accurate measurements? Have you read what I posted? How can you obtain accurate measurements. If it were possible, then I wouldn't have given my input!

When I worked for Marconi, we were fuel pump calibration specialists. That is where I have obtained most of my information, regarding this issue.

It is a waste of time, for the average driver, to attempt to check mpg. If you are only a small percentage out, this can be magnified, by checking over a period of time.

Most of us know that vehicle manufacturers figures are inaccurate, so why do we think that we can do better?

 

[Deleted member 9849]

................................................................
Most of us know that vehicle manufacturers figures are inaccurate, so why do we think that we can do better?

I always check my mpg at every fill using the brim to brim method in conjunction with the odometer.I realise that it will not be strictly accurate every time but over a period of several months it should give a fair indication of average fuel consumption.It has been as low as 22mpg right up to 31mpg.As long as it is consistently between these figures then I know the engine is working well and there is no cause for concern.

I budget for 25mpg which I am happy with and have peace of mind knowing that the old lump is functioning well.

 

[Robmac]

Underground storage tanks ARE affected by temperature changes, even if these are not so great, also your vehicles tank IS definitely affected.

The camber effect IS NOT negated, to any significant degree, in the way that you have suggested.

Wind speed could average out, but certainly can't be taken for granted! It could be one of the reasons that calculations vary.

Accurate measurements? Have you read what I posted? How can you obtain accurate measurements. If it were possible, then I wouldn't have given my input!

When I worked for Marconi, we were fuel pump calibration specialists. That is where I have obtained most of my information, regarding this issue.

It is a waste of time, for the average driver, to attempt to check mpg. If you are only a small percentage out, this can be magnified, by checking over a period of time.

Most of us know that vehicle manufacturers figures are inaccurate, so why do we think that we can do better?

Whilst I appreciate your obvious knowledge of the subject in hand, are you suggesting that we should be completely oblivious to how our vehicles are performing, or do you have a better solution?

That may sound condescending, but it isn't supposed to, it is a genuine question.

 

[Mick H]

Whilst I appreciate your obvious knowledge of the subject in hand, are you suggesting that we should be completely oblivious to how our vehicles are performing, or do you have a better solution?

That may sound condescending, but it isn't supposed to, it is a genuine question.

I was only attempting to raise awareness, that because there are far too many variables, fuel consumption figures are ONLY ESTIMATES, and should NOT be regarded as accurate.

As with most things, people will believe what they want to. Topics like this will be raised in future posts, but possibly, I have given 'Thinking people' food for thought.

 

[Fazerloz]

Because a fuel expands/contracts, according to temperature, again, you wouldn't know how this affected your calculations. .

Is this not negated on modern vehicles by the fuel temperature sensor. And the automatic temperature compensator on modern fuel dispensers. If not we had all better fill up first thing in the morning when the fuel is more dense.