PHEV as a towcar

[ProfJohnL]

Yep - comparing EVs via MPG is pointless (as it relies on cost of petrol or diesel to be useful). But if you want to figure out how an EV will (or wont) fit your use case, knowing how much it might cost you (or save you) in todays prices can be useful. Thats what Parkers miles per pound is attempting.

You even almost lost me with your post full of actual values, it was not very readable, but hey! who am I to criticize... 🤔

Now for some clarity, unless you are using MPG to mean something other than miles per gallon, how can the cost of electricity change an MPG? A mile is a linear distance and a gallon is a statutory volume. I do acknowledge they may have differences under different weights and measures around the world.

And a side note for Roger,
These differences do mean that for example an MPG quoted in the USA is not the same as we would get in old blighty, because both the American Mile and gallon are different to our imperial measures.

 

[otherclive]

You even almost lost me with your post full of actual values, it was not very readable, but hey! who am I to criticize... 🤔

Now for some clarity, unless you are using MPG to mean something other than miles per gallon, how can the cost of electricity change an MPG? A mile is a linear distance and a gallon is a statutory volume. I do acknowledge they may have differences under different weights and measures around the world.

And a side note for Roger,
These differences do mean that for example an MPG quoted in the USA is not the same as we would get in old blighty, because both the American Mile and gallon are different to our imperial measures.

??????? The U.K. and US miles are the same in imperial and SI units. The latter being formally agreed in 1959 But were you referring to International, Standard or Statute miles. Confused dot com has nothing on the system of units still buzzing around.

 

[Tobes]

You even almost lost me with your post full of actual values, it was not very readable, but hey! who am I to criticize... 🤔

Now for some clarity, unless you are using MPG to mean something other than miles per gallon, how can the cost of electricity change an MPG? A mile is a linear distance and a gallon is a statutory volume. I do acknowledge they may have differences under different weights and measures around the world.

And a side note for Roger,
These differences do mean that for example an MPG quoted in the USA is not the same as we would get in old blighty, because both the American Mile and gallon are different to our imperial measures.

Yeah it is a bit unreadable. I was trying to put some concrete under the formulae.
As for the variable MPG equivalent, my understanding is that the translation used is based on the pence per mile, not the energy in the tank. The idea being that MPG is related to something that is translated to running costs. Using the pence per mile translation (I.e. start with the average cost of a gallon of fuel, and use the ppm based on the average charging cost, do derive available distance) gives a number that can be directly understood as running costs.

The “true” model (use the caloric value of petrol as a proxy for electrical energy) assumes perfect exchange of petrol/diesel for electricity. Though I will calculate that translation too, and see how it stands up

 

[Tobes]

??????? The U.K. and US miles are the same in imperial and SI units. The latter being formally agreed in 1959

Correct, but a U.S. gallon (3.78 litres) is smaller than an Imperial Gallon (4.54 litres).
i.e. 37mpg US is the same as 45mpg UK.

 

[RogerL]

And a side note for Roger,
These differences do mean that for example an MPG quoted in the USA is not the same as we would get in old blighty, because both the American Mile and gallon are different to our imperial measures.

The US mile has been the same as the UK mile since 1959.

I'm well aware that American EPA mpg uses the smaller US gallon rather than the larger Imperial gallon - but the conversion is worthwhile IMO as the EPA test method is more realistic for normal use than the NEDC/WLTP officially used in EU/UK - but sadly only works for the limited number of vehicles sold both in the UK and USA with no mechanical changes.

 

[xtrailman]

That great news i am with Octopus customer

I am and don't rate them having been with Avro before.

 

[xtrailman]

??????? The U.K. and US miles are the same in imperial and SI units. The latter being formally agreed in 1959 But were you referring to International, Standard or Statute miles. Confused dot com has nothing on the system of units still buzzing around.

The USA mpg is different to the UK mpg. But you probably know that.

 

[Buckman]

The US mile has been the same as the UK mile since 1959.

I'm well aware that American EPA mpg uses the smaller US gallon rather than the larger Imperial gallon - but the conversion is worthwhile IMO as the EPA test method is more realistic for normal use than the NEDC/WLTP officially used in EU/UK - but sadly only works for the limited number of vehicles sold both in the UK and USA with no mechanical changes.

I have a Jeep and when I switch to miles it will read for instance 50000 miles which is 80467km. However when I switch back to km on the car the reading is different and may show 80900km. Weird considering the car is built in the EU?

We buy fuel in litres and not gallons and surely it is easier to use litres per 100km than mpg? How many other countries globally still use the antiquated system of mpg?

 

[RogerL]

I am and don't rate them having been with Avro before.

I was transferred to Octopus when Avro went bust - apart from the loss of the cheap fixed tariff, Octopus customer service does seem very good.

 

[ProfJohnL]

I'm sorry Tobes, I am still having trouble following your train of thought on this subject, Does your use of "MPG" mean Miles per Gallon? If so there is no component of that definition that can be affected by a cost.

I'm wondering if I fully understand the acronyms you are using. Acronyms have their uses but it does depend on the people you're communicating with understanding the context and their meaning.

I'm pretty certain most of us have found that different fields of work or hobbies generate their own acronyms and you don't have to look very far to find the same acronym being used in two entirely unrelated situations and having very differnt and unrelated implications.

To avoid confusion, when I write in a subject that is going to use acronyms, when I use a term for the first time in a document I write the full definition immediately followed by the acronym so there is an in document reference to its exact meaning. I can the use the acronym on its own later on within the document. In many Quality related documents you may well have a section specifically related to acronyms and their definitions so there is no room for doubt.

For example;
Audio engineers should be aware of a Peak Programme Meter known as a "PPM"

One of the measures of success in Quality Management systems may look for a failure rate of less than 'n' "Parts Per MIllion" or "PPM"

What definition do you put on the "ppm" your using?

 

[Tobes]

I'm sorry Tobes, I am still having trouble following your train of thought on this subject, Does your use of "MPG" mean Miles per Gallon? If so there is no component of that definition that can be affected by a cost.

MPG - miles per gallon.
ppm - pence per mile
mpp (Parkers guide) or mp£ (my usage) miles per pound (sterling).

MPG has no cost component - I aggree. The problem is that EVs have no way of using the energy in a gallon of fuel to derive an efficiency, just as ICE cars have no way of using an electrical kWh as a source of energy to derive efficiency.

One model for generating a comparison is to use a common proxy for fuel source - that of monetary value. I.e. determine the cost to travel a distance (pence per mile - ppm) in one mode and use it to derive the cost to drive a distance in a different mode. Its a flawed model in that its only valid for a given fuel and electricity price, right now, today. Back when electricity and fuel prices were relatively stable (prior to the end of 2021), the pence per mile proxy for mile per gallon (MPG) and miles per kWh (mpkWh) made some sense, as they were only impacted a little by small fluctuations in cost. With the volatility in both Oil and Electricity prices - its a bit harder.

An alternative model is to try and derive the efficiency based on the pure energy input - electrical kWh for an EV and gallon of fuel for an ICE. This too is flawed as there is a) different amounts of energy in 1G of petrol vs 1 G of Diesel, and neither can be directly equated to the energy in 1kWh of electricity. (How much electricity is there in 1G of petrol?).

If we make the raw assumption that 1 litre of petrol is 9.7kWh. then one Imperial Gallon is 44kWh, then
EV MPG = mpkWh * 44

I.e. my EV is 3.1mpkWh or 136MPG.

 

[ProfJohnL]

Thank you for your explanation, and in fact it agrees with points I made in posting 88.

I do agree it is sometimes desirable to be able to know the running cost per distance, but trying to use the cost of fuel/energy as the "proxy" is never going to be a long term constant. It will always be better to have the quantity of fuel/energy per distance as the output, and it will then be up to the reader to convert that to a cost based on the prevailing prices available to the user.

 

[Dustydog]

I and my friend Alice have just returned from a splendid break in Wonderland.
We met some incredibly clever people . We learnt so much , so complicated , sadly we have forgotten most of it .
But we do recall MPG, MP KWH, MPL,KPKWH,PPM,MPP,nPPM,NEDS,WLTP,EPA,WTF, PHEV, AVRO, OCTOPUS, ILBS , OZS ,ICE,
We shall now have a cup of tea at todays party and probably go back to our tried and tested method of buying our fuel in £20 note per fill up🙃🙃😵‍💫

 

[Beachball]

I am and don't rate them having been with Avro before.

So far i have been very happy with Octopus you could always change to another energy supplier

 

[ProfJohnL]

I and my friend Alice have just returned from a splendid break in Wonderland.
We met some incredibly clever people . We learnt so much , so complicated , sadly we have forgotten most of it .
But we do recall MPG, MP KWH, MPL,KPKWH,PPM,MPP,nPPM,NEDS,WLTP,EPA,WTF, PHEV, AVRO, OCTOPUS, ILBS , OZS ,ICE,
We shall now have a cup of tea at todays party and probably go back to our tried and tested method of buying our fuel in £20 note per fill up🙃🙃😵‍💫

How about a Woosie competition to work out what each of these really mean?
MPG, MP KWH, MPL,KPKWH,PPM,MPP,nPPM,NEDS,WLTP,EPA,WTF, PHEV, AVRO, OCTOPUS, ILBS , OZS ,ICE,

 

[Dustydog]

How about a Woosie competition to work out what each of these really mean?
MPG, MP KWH, MPL,KPKWH,PPM,MPP,nPPM,NEDS,WLTP,EPA,WTF, PHEV, AVRO, OCTOPUS, ILBS , OZS ,ICE,

Good idea but if it doesn’t include “ Bar hunt” nonchance😁

 

[Tobes]

MPG - miles per gallon (of beer or wine). How far you go on holiday is directly proportional to the amount of adult beverage you take with you "just in case you cant get to the shops".

 

[Buckman]

MPG - miles per gallon (of beer or wine). How far you go on holiday is directly proportional to the amount of adult beverage you take with you "just in case you cant get to the shops".

Don't forget the toilet rolls!

 

[Dustydog]

MPG - miles per gallon (of beer or wine). How far you go on holiday is directly proportional to the amount of adult beverage you take with you "just in case you cant get to the shops".

Makes a note to check Hutch’s Coachman😉

 

[Hutch]

Makes a note to check Hutch’s Coachman😉

I can make it all the way to Chablis, in France without a stop to top up the wine. 🍷🍷🍷

 

[Dustydog]

I can make it all the way to Chablis, in France without a stop to top up the wine. 🍷🍷🍷

Cast iron bladder😉

 

[ProfJohnL]

Good idea but if it doesn’t include “ Bar hunt” nonchance😁

Oh you mean Miles to Bar (MTB) or Miles to Beer or shold it be DtA -Distance to Alcohol

 

[JezzerB]

In my case MPG has to be Minutes per Gin ie how long after set up it takes to be sat relaxing after first gin. No awning 30, awning 75! Ish

 

[otherclive]

The gap between public chargers and EV numbers continues to widen according to Autoexpress. and Government figures. But this doesn’t address the fact that a lot of EV will charge at home. Where I live I see increasing numbers of EV but the local chargers seem to be rarely in use. In fact somewhat ironic it’s British Gas service vans that I see mostly charging at a nearby Lidl.

Gap between electric car ownership and charging provision grows | Auto Express

Official figures reveal 29 per cent more electric vehicles were sold in March 2022 than new public chargers were installed

www.autoexpress.co.uk

 

[ProfJohnL]

For the majority of UK EV drivers, they have already managed their charging needs for their day to day driving, but the difficulty arises when having to make longer than usual journeys. That's where the public charging network is not keeping pace, and the facilities are inadequate. Especially on major routes.

I'm inclined to believe, as EV's grab an even bigger share of the market, we're likely to see some conventional filling stations swapping some of their Dino juice dispensers to EV chargers. And not just shoving them in between the air dispenser and car wash.