Cost comparison

Patrick W · Aug 11, 2015

I'm trying to compare the cost of "fuel" to drive my S vs my ICE. Anyone here care to check my figures?

My ICE gets 27 MPG.

Gasoline currently costs $2.96 per gallon (a bargain compared to the rest of the world).

The display on my S says I have driven 4,090 miles since resetting the counter and that during that time I used 1,136 kwh.

With electricity currently costing $0.088854 per kwh I spent $100.93 to power the S.

If I had driven the same distance in my ICE I would have burned 151.5 gallons of gasoline costing $448.40.

So about $101 in "fuel" for the S and about $450 in fuel for the ICE.

Does that look right?

Thanks!

stevezzzz · Aug 11, 2015

Seems right, and in line with other comparisons I've seen.

deonb · Aug 11, 2015

Unless you've measured the 1136 kWh at the wall, your numbers are probably a little light.

Your actual usage was likely around 15% higher than that (so 1306 kWh), due to charging losses and vampire drain.

That would mean $116 instead of $101.

Not a huge difference though.

tstafford · Aug 11, 2015

Side note - You sure have cheap electricity in UT.

JPP · Aug 11, 2015

In the SF Bay area, my cheap night rate on a tiered EV plan is $0.11/kw. You don't want to know what the peak rate is.....

brucet999 · Aug 11, 2015

Patrick W said:
I'm trying to compare the cost of "fuel" to drive my S vs my ICE. Anyone here care to check my figures?

My ICE gets 27 MPG.

Gasoline currently costs $2.96 per gallon (a bargain compared to the rest of the world).

The display on my S says I have driven 4,090 miles since resetting the counter and that during that time I used 1,136 kwh.

With electricity currently costing $0.088854 per kwh I spent $100.93 to power the S.

If I had driven the same distance in my ICE I would have burned 151.5 gallons of gasoline costing $448.40.

So about $101 in "fuel" for the S and about $450 in fuel for the ICE.

Does that look right?

Thanks!

You used about 8% - 10% more AC electricity than the battery received in DC. Did you measure kWh usage at a dedicated power meter, or calculate from battery metrics?

Patrick W · Aug 11, 2015

deonb said:
Unless you've measured the 1136 kWh at the wall, your numbers are probably a little light.

Your actual usage was likely around 15% higher than that (so 1306 kWh), due to charging losses and vampire drain.

That would mean $116 instead of $101.

Not a huge difference though.

Ah, had not thought of that. But even with that I'm guessing I actually spent well under $100 as a lot of what I used came from super chargers.

sorka · Aug 11, 2015

In 8K miles of driving, I've only charged about 1/3 of the miles at home. The rest was at work and at superchargers. I put 1600 miles alone last weekend and all but 200 miles of it was on super chargers.

Patrick W · Aug 11, 2015

brucet999 said:
You used about 8% - 10% more AC electricity than the battery received in DC. Did you measure kWh usage at a dedicated power meter, or calculate from battery metrics?

Nothing that fancy. Just used the energy usage shown in the Trip Menu.

But no matter how it's calculated it's pretty obvious electrons are cheaper than carbon.

BoerumHill · Aug 11, 2015

One TMC member used a meter on his home outlet and blogged about the one month test. Not sure why but his efficiency - 23% loss - was significantly worse than what others have reported (typically 12-15%.)

Driving the Model S costs you more than you think | Tesla Living

deonb · Aug 11, 2015

BoerumHill said:
One TMC member used a meter on his home outlet and blogged about the one month test. Not sure why but his efficiency - 23% loss - was significantly worse than what others have reported (typically 12-15%.)

Driving the Model S costs you more than you think | Tesla Living

Markup vs. markdown effect.

18% loss in efficiency, marked up becomes 22% "higher than expected".

BoerumHill · Aug 11, 2015

deonb said:
Markup vs. markdown effect.

18% loss in efficiency, marked up becomes 22% "higher than expected".

Bingo! Great point, makes perfect sense when you run the numbers. His efficiency was 81.4%; consumption was 728, actual meter usage was 894. But if you extrapolated the cost (I know he paid $0.24 per other blog posts, no TOU plan available in MA), the consumption appears to have cost $174.72 when in fact it was $214.56, or 22.8% higher.

deonb · Aug 12, 2015

BoerumHill said:
Bingo! Great point, makes perfect sense when you run the numbers. His efficiency was 81.4%; consumption was 728, actual meter usage was 894. But if you extrapolated the cost (I know he paid $0.24 per other blog posts, no TOU plan available in MA), the consumption appears to have cost $174.72 when in fact it was $214.56, or 22.8% higher.

Or put another way, 100 / 81.4 = 122.8%

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Cost comparison

Patrick W

Active Member

stevezzzz

R;SigS;P85D;SigX;S90D;XP100D;3LR;YLR

deonb

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tstafford

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JPP

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brucet999

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Patrick W

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sorka

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Patrick W

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BoerumHill

not great not terrible

deonb

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BoerumHill

not great not terrible

deonb

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