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Gas Savings Support Thread

James 2 years ago updated by Kjartan Björnsson 5 months ago 19

Please post issues/comments here.

So My currency is icelandic and price of fuel is like 220kr per liter, but the Gas cost field only goes up to 100 

Hi,


Suggestions :


Change Charging Rate KPH to km/h https://en.wikipedia.org/wiki/Kilometres_per_hour


i created my own post before i saw this thread but wanted to add it here as well...this probably needs to be thought out a little better but here it is...

Now that you have added the cost savings comparison vs gas, which is an awesome addition. When vehicle is idle, sleeping, etc., I would like to see range loss as a cost or reduction in savings compared to gas (as there is no range loss on ICE vehicles when engine is off)

Any way to have the cost savngs displayed on the Calendar page? Would be also cool to have it year to date and lifetime savings.

Do I have to do something different to get gas savings for imperial gallon? At 5 per gallon I get sensible numbers for US and 1 per mile imperial.


 

Hi,


Sorry for the delay.  Are you still seeing this issue?


Thanks,


James

Yep still not clear on it - I have a 34 miles driven and gas savings of £34.17

I'm using MPGe, 33.7 kWh/G, Gas Cost £5 per gallon  

Ahhh...yes there was a variable swapped for imperial.  Does that look better?

sorry for delay. Yes working better but is tillnhave to figure out all the details :-)

Thanks for great support and an great app

why is KWh in 1 litre figure even necessary?  I don’t think it’s of much interest how much energy has been lost due to inefficiencies of ice.

Under review

The idea of comparing gas to electricity is how much energy a liter of gasoline creates.  All of the calculations are based of of this and it's adjustable in case someone does not want to use the EPA estimates or different countries have their own estimates.

Great new feature! 

Although, not sure how to set it up correctly. I'm in Europe, therefore gas is in liters, consumption is in liters/100km. So I set it up like this: 


Display - l/100km

kWh Gas Equivalency - 8.9 (as per help text on form)

Gas Comparison - 9.9 (average consumption in l/100km of my previous car)

Gas Cost - 1.6 (price of gas per liter)


This morning I drove 10.36 km. The cost column on the drive table shows:

- Cost: 0.37 (cost of electricity I guess?)
- Gas Savings: 1.67 (is this the gas my ICE would have used? According to my calculation this would be (9.9/100)*10.36=1.64)
- 1.6 Le/100 km (not sure what this is. Can you explain?)


Thanks!

Dan

Cost is the kWh used * home energy cost in settings.


Gas savings is the amount the gasoline would cost based on the rating entered for your ICE.   I changed the calculation here so it matches up to your numbers.  Much easier way than what I was using.  Thanks.


Le/100 km is the e-rating of liters of gas used per 100km, based on a liter of gas containing 8.9 kWh.  

((1.47/8.9)*100)/10.36

((kWh Used/kWh Per Liter)*100)/Kilometers Driven

Let me know if that seems to match up.  It matches up with the references I was looking at but I could be wrong.


Thanks,


James






I think gas saving doesn't show saving, it shows cost of gas to travel the distance.  Perhaps the formula should deduct cost of energy from cost of gas.

That is the original way I had it but I wasn't sure if users would know Gas Savings meant the difference between the energy cost and gas cost.  I changed it show what the gas cost would have been for the entire trip like it is now.


Do you think "Gas Savings" suffices for the difference between energy and gas usage?


Thanks,


James

Really should change Column Name to Gas Cost since that is what you are showing.  This would make it much less confusing.

Perfect, thanks for following up James. It all makes sense now.


As for the 8.9 kWh per liter of gasoline, do we not have to consider the (in-)efficiency of the ICE we compare to? In other words, if 1 liter of gas contains the equivalent of 8.9 kWh, but the engine converts only 30-40% of this into kinetic energy, should this be taken into consideration for the e-rating of gas?


Cheers,

Dan


Edit: found this: https://www.quora.com/How-many-kWh-can-you-get-from-burning-1-litre-of-gasoline

You could get VERY complicated if you want to and adjust that kWh and ICE rating to anything.  However the way it is currently should be fine since that kWh number is already based on the EPA's formula described below.


The MPGe metric was introduced in November 2010 by EPA in the Monroney label of the Nissan Leaf electric car and the Chevrolet Volt plug-in hybrid. The ratings are based on EPA's formula, in which 33.7 kilowatt hours of electricity is equivalent to one gallon of gasoline, and the energy consumption of each vehicle during EPA's five standard drive cycle tests simulating varying driving conditions.[18][19]All new cars and light-duty trucks sold in the U.S. are required to have this label showing the EPA's estimate of fuel economy of the vehicle.[20]


I did change the recommended kWh per liter to 8.86, I had it rounded to 8.9.