I've got a math question about HEV vs BEV...

[IMDIDOC]

Each month I take the kwh used time the cost per kilowatt from my electric bill. I then divide that by the number of miles to determine the cost per mile. I'm between 4 and 5 cents per mile. I compare that to my wife's ICE based on the cost of gas and her mileage.
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[RickMachE]

The problem with comparing a HEV or a PHEV is really a case usage situation. If Mary drives locally, keeps her speed at 35mph, her efficiency is widely different than Tom that has to get on the freeway.

 

[SpaceEVDriver]

OK, thank you, I guess I was overthinking it.

You can also flip the algebra.

55 miles/gallon / 33.7 kWh/gallon = ~1.6 miles/kWh.

Your Mustang Mach-E probably gets around 2 to 3.5 miles/kWh.

The Ioniq hybrid carries around 12 gallons of gasoline, so it has approximately the energy storage equivalent to a 404 kWh battery.

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You can start adding in all the extra inefficiencies of generating and delivering the electricity, but then you should probably also add in the costs of getting that gallon of gas to your vehicle. How many kWh of energy are used to deliver a gallon (33.7 kWh) of gasoline to the consumer?--it's a lot more than people think.

 

[MachTee]

We also have an Ioniq, 2020 plug in version, that mostly my teenager drives. It's about $0.035 a mile to drive, in either electric only mode based on $0.15/kWh, or combined EV/HEV mode which averages in the low-mid 80's MPG based on $3/gallon. IIRC when I had the MME it was around $0.045 a mile to drive outside of winter.

 

[deadduck]

Ok, so I was driving my wife's 2019 Ioniq Hybrid (not plug-in) today, and I was worried it was at a quarter tank and it would need gas soon, but then I looked at the DTE and it said 204 miles. This thing is crazy efficient, 55 mpg, love it.

Anyways, I was trying to figure out how to compare the fuel efficiency of an HEV to the Mach-E. My guess is the HEV is gonna be more efficient? Anyone know a calculation to do this as a fair comparison and not the dumb MPGe?

Would it be figuring out the miles per kWh of the HEV?

Didn't read enough, looks like someone already did this, but I'll just leave it here.

Do it by miles to cost per gallon for fuel, and miles by KwH for the EV.

Assuming $5.00/gal and .26/KwH. Both about right here in California.

$5/55 = .09/mile

.26 / 3.2 = .078/mile

You can extend the math to your total miles.

A hybrid, however, pretty much destroys an EV in overall cost because they're so much cheaper, when feature matched, even after tax credits. PHEV's, however, pencil in last because they cost almost as much as a EV and don't have any credits.

 

[Reign of Ravens]

As the thread shows, efficiency can be thought of in many different ways. The way I think of it, gasoline is a highly efficient form for energy storage (energy per weight/size) that gets paired with relatively inefficient engines, while batteries are currently relatively inefficient forms of energy storage that are paired with extremely efficient engines.

What the switch to electric really opened my eyes to is just how much energy gets taken up by transportation. Fuel usage felt a bit inaccessible but energy usage allows direct comparisons to other devices and things. For example, with 40-some solar panels my average daily energy generation is somewhere around 40-50 kWh each day (I live in a cloudy area; with full sun we can get into the 90's, haven't broken 100 yet but it might be possible). Running air conditioners, my house usage is somewhere around 15-20 kWh in the day (and before I used my A/C regularly, I've seen daily draw as low as 9 kWh for the day, although that was rarer). My daily commute is a bit over 30 miles and traffic in Hawaii is pretty awful so a lot of that is spent idling; the Mach-E takes 8-9 kWh per day. Adding that to my total electricity draw, transportation from a single vehicle occupies about a third of my total electricity usage.

Granted, with our solars and Tesla Powerwalls combined, we don't pay anything (or if you prefer, we paid it all up-front). In fact, we joined a virtual power plant program and now the electric company owes us money. But it's quite a bit of energy...

 

[Msnwcpa]

What you should do is convert to cents per mile. If the car gets 55 MPG, and gas is $3.50 a gallon, then it costs ~6.4 cents per mile to drive the hybrid. (3.50 / 55 = 0.063636). And if you get 3 miles per kWh, and electricity is 20 cents a kWh, then it costs you 7.3 cents per mile after taking into account charging losses, which are about 10% (20 / 3 = 6.666666. 6.66666 * 1.1 = 7.333333).

In some cases, the hybrid is cheaper than the MME.

This exactly how I compared my Lexus Hybrids and my Prius to my MME.

Truth is it's costs me about $0.18/kwh including taxes.

If I get 3miles/kwh then cost per mile is 6cents, which is roughly the cost of Prius at 50miles/gallon at 3.8x.

If I drive MME efficiently at over 4miles/Kwh then I save, plus save on any maintenance costs.

Hybrids are cheaper to drive, no range anxiety. Prius maintenance costs are extremely low. Replaced brakes twice have over 200k miles.

 

[SpaceEVDriver]

As the thread shows, efficiency can be thought of in many different ways. The way I think of it, gasoline is a highly efficient form for energy storage (energy per weight/size) that gets paired with relatively inefficient engines, while batteries are currently relatively inefficient forms of energy storage that are paired with extremely efficient engines.

What the switch to electric really opened my eyes to is just how much energy gets taken up by transportation. Fuel usage felt a bit inaccessible but energy usage allows direct comparisons to other devices and things. For example, with 40-some solar panels my average daily energy generation is somewhere around 40-50 kWh each day (I live in a cloudy area; with full sun we can get into the 90's, haven't broken 100 yet but it might be possible). Running air conditioners, my house usage is somewhere around 15-20 kWh in the day (and before I used my A/C regularly, I've seen daily draw as low as 9 kWh for the day, although that was rarer). My daily commute is a bit over 30 miles and traffic in Hawaii is pretty awful so a lot of that is spent idling; the Mach-E takes 8-9 kWh per day. Adding that to my total electricity draw, transportation from a single vehicle occupies about a third of my total electricity usage.

This is what I felt too.
I *knew* the numbers before I bought a Mustang.
But experiencing the energy cost of driving really blew me away. Even if the dollar cost is low, the energy required to move a massive object many thousands of km every year at very high rates is a lot!

 

[EVandSolar]

Didn't read enough, looks like someone already did this, but I'll just leave it here.

Do it by miles to cost per gallon for fuel, and miles by KwH for the EV.

Assuming $5.00/gal and .26/KwH. Both about right here in California.

$5/55 = .09/mile

.26 / 3.2 = .078/mile

You can extend the math to your total miles.

A hybrid, however, pretty much destroys an EV in overall cost because they're so much cheaper, when feature matched, even after tax credits. PHEV's, however, pencil in last because they cost almost as much as a EV and don't have any credits.

PHEVS have tax credits. My daughter just bought a lightly used Hyundai Ioniq PHEV. She gets a $4,000 federal tax credit and a $1500 state rebate. State rebate might end up at $2500 due to her lower income.

I would argue that the right PHEV's are currently the most economical overall form of transportation other than bicycle or walking. 30 miles all electric range covers 2x my daughters daily commute so she has plenty of EV range for errands even on a work day. As a dad, I don't have to worry about sketchy 3rd party charging networks if she takes a trip, in which case she gets the aforementioned 55-60 mpg.

Used Chevy Bolt could be argued as one of the most economical as well I suppose. We ruled this vehicle out due to range issues mostly associated with the lousy 3rd party charging network. It's fine for me with our Kia Niro EV for the most part, but not for a 19 y.o. girl traveling alone, IMO.

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