CoViD & Gasoline Usage

[guidoLaMoto]

Originally Posted by EricBoyd

I sold my 17mpg Toyota Tacoma last November and purchased a fully-electric car. So, the gas drop doesn't affect me. I'm getting ~300 miles of range at the cost of about $4.40. At today's gas prices in my Tacoma, that range would cost me about $30.

I own and operate a business that's considered essential, so my driving habits haven't changed.

Show me where I made a mistake in calculations:


Let' say gas is now 200 cents/gal and 1kW-hr is 20 cents. Your car was getting 17mpg, so fuel costs are
200/17 ~ 12cents / mi. (@ $2.50/gal, it's up to `15cents /mi )….You state 440 cents to drive 300 mi ~ 15 cents/ mi on electricity. ….If 300 miles would cost you $30, then you're getting 20-25mpg)




Given that 1 kW-hr = 3.6 x 10 ^6 J and 1 gal gas = 1.2 x 10^8 J '




17mi takes 1.2 x 10^8 J t drive on gasoline.






But, if we calculate energy usage, 1kW-hr is 3.6 x 10^8J and it costs 20cents..> 440/20 = 22kW-hr to drive your 300 miles-->
3.6 x 10^8 J /kW-hr x 2.2 x 10^1 kW-hr = 7.9 x 10^9 J-->
7.9 x10^9J ./. 1.2 x 10^8 J/gal = 6.6 x 10^1 = electric energy equivalent to 66 gal of gas--> ????
(@ 15c/kW-hr, it's closer to 90gal of gas)

[Nov3]

Originally Posted by guidoLaMoto

Show me where I made a mistake in calculations:


Let' say gas is now 200 cents/gal and 1kW-hr is 20 cents. Your car was getting 17mpg, so fuel costs are
200/17 ~ 12cents / mi. (@ $2.50/gal, it's up to `15cents /mi )….You state 440 cents to drive 300 mi ~ 15 cents/ mi on electricity. ….If 300 miles would cost you $30, then you're getting 20-25mpg)




Given that 1 kW-hr = 3.6 x 10 ^6 J and 1 gal gas = 1.2 x 10^8 J '




17mi takes 1.2 x 10^8 J t drive on gasoline.






But, if we calculate energy usage, 1kW-hr is 3.6 x 10^8J and it costs 20cents..> 440/20 = 22kW-hr to drive your 300 miles-->
3.6 x 10^8 J /kW-hr x 2.2 x 10^1 kW-hr = 7.9 x 10^9 J-->
7.9 x10^9J ./. 1.2 x 10^8 J/gal = 6.6 x 10^1 = electric energy equivalent to 66 gal of gas--> ????
(@ 15c/kW-hr, it's closer to 90gal of gas)

Well for starters you messed up the miles per gallon . 17 miles per gallon is $2.00 not 20 cents.
Those decimals will get ya each time.
He is getting 300 miles at 4 .40$ on electric.
Doubt his $ 4.40 cents in gas will get him 300 miles. Might get him 40 miles...

[guidoLaMoto]

Originally Posted by Nov3

Well for starters you messed up the miles per gallon . 17 miles per gallon is $2.00 not 20 cents.
Those decimals will get ya each time.
He is getting 300 miles at 4 .40$ on electric.
Doubt his $ 4.40 cents in gas will get him 300 miles. Might get him 40 miles...

No, I used 200 cents, not 20..... 200 cents /( 300 mi/17 mi/gal)= 11.4cents/mi for the ICE.


But I did screw up the EV cost--440 cents/300 mi = only 1.5 cents per mile....


I used the 20 cents for the cost of electricity. …


Calculating the energy usage of the ICE, then calculating how many kW-hr of electricity that would convert to, he must be using :


17mpg & 300 mi--> ~17 gal.... 17gal x 1.2 x 10^8 J/gal = 2 x 10^9 J


2 x 10^9 J / 3.6 x 10^8 J /kW-hr = 6 x 10 kW-hr @20 cents/kW-hr, that's 60 x 20 = $12.00, so he'd be spending 1200/300 = 4 cents per mile..


...That makes good sense for energy usage and good cents for savings (until you figure in the excess premium paid for an EV over a similarly equipped conventional vehicle. You have to drive it an awfully lot before you make up the difference in gas savings.)


Edit: It just dawned on me: While the ICE burns 120 M J worth of chemical energy, only 15-20% of that actually move the car down the road. The rest is lost inefficiently as heat...The EV, OTOH has much better efficiency at converting the electrical energy into kinetic energy (~90%). The inefficiencies occur at the point of power generation, in its transmission and in losses while charging & maintaining batteries, so they come out about the same in terms of total energy usage. It's just that electricity is so darn cheap compared to petrol fuels.

[sholomar]

This virus is just what the doctor ordered as far as the planet goes. As much as many people like to take a stand to be green, a lot of these same people are jetting all over the world, wanting to experience everything. They fail to figure in that if everyone has this same attitude, the increase in carbon emissions can be extreme.


I'm not saying everyone should be a hermit, in fact most people won't even if it means increasing carbon emissions, but you have to admit the changes in the way we live our lives have been a positive for the planet. I hope things like working from home, having appointments via video apps and things of this sort become the norm, decreasing our need to travel all over just to have a conference or see a doctor in person when the same thing can be done via an app and video conferencing.

But that wouldn't be as fun as jetting all over the world to see new and exotic destinations...

[jcp123]

Naw. I am a bit of a special case in that I’m trucking, so my car sits for large stretches of time. I average about 300 miles per month. But I do rather like driving as a hobby. If I had good twisty roads like I did in California, and weren’t trucking, I’d probably be all over those things quite a bit. My Civic will win zero races, but it’s a fairly fun car to drive hard.

[guidoLaMoto]

Originally Posted by stockwiz

This virus is just what the doctor ordered as far as the planet goes....

??? Even if 10 million people die, that's only one in 1,300 people. Gaia won't even notice...So far, it's 20x less than that.


With US fuel usage down by over half, world airlines traffic down by 75% and closure of much of the word's manufacturing, co2 levels at Mauna Loa haven't discernably changed from their usual upward trend.....In fact, last Friday, it finally hit 415ppm for the first time...It just goes to show you how much "Anthropogenic" is involved in "GW." https://www.esrl.noaa.gov/gmd/ccgg/trends/

[Philip T]

For a handy and accurate short cut on your EV calculations -- 250 watt-hours gets you a mile.

or 0.25 kWh = 1 mile.

Generally true for Volt, Bolt, Tesla, etc.