Why would you choose a Prius over a Chevy Volt?

Yes, but if "Physics" dictated a result, it wouldn't matter what the use pattern was. Physics has nothing to do with your spreadsheet.

I also don't believe your situation necessarily corresponds to 9/10 use cases.
The spreadsheet is a great idea to determine your specific costs. Please don't assume your specific inputs are the same as 9/10 of the use cases out there.

 

It's why I left all the formulas in. Anyone can copy it and punch in their specific numbers. I have tried a number of scenarios and few heavily favor one efficient car over another.

I changed some numbers: $3 regular gas, 47 mpg vehicle, average 40 miles per day, 4x500 mile road trips per year. Total miles per year 16,600, total saved per year with Volt: $180.

Change to 80 miles per day average, 31,200 miles per year. Total saved with 47mpg vehicle per year over Volt: $180.

All I am saying is it is helpful to have a figure like $180 instead of using the most extreme possible driving habits as a benchmark between potential extremes. I don't really think that is productive, but that appears to be what the usual conversation is.

 

I agree completely with your final paragraph

The appeal to physics was just way off base.

 

Ah, okay, sorry about the physics. From what I understand, and I may be incorrect, theoretically a ~3,000lbs gasoline vehicle could get 150mpg (I think 149 is the often-quoted figure). But, engine friction, temperature etc. ruin that possibility. Electrified vehicles minimize inefficiencies such as idling and braking, but an engine is still subject to the same physical inefficiencies other engines are. Engines can be modified to be more efficient, but then compromise instantaneous power or some other variable.

Weight reduction is the easiest way to improve efficiency. This is why the same exact 19kWh / 192-cell battery technology in the 2015 Spark EV is rated at 82 miles while the 2016 Volt will probably be rated far less.

That is what I meant by the physics of it. Any comparable vehicle of the same size that is already optimized for braking, idling, etc. will probably be about as efficient as a similar vehicle, especially if the main difference is efficiency geared to driving style with a varied average driving style.

I might be way off. If you'd like to explain what is wrong with these suppositions, I'd be more than interested.

 

I'd say that is true with regards to internal combustion engines.
When you bring electric motors into the equation you have a whole new ballgame.
An electric motor is 3-4 times more efficient than an internal combustion engine and on average, the cost of electricity is much lower than that of gasoline.

So with similar cars, the fuel costs come out way ahead. The up front costs are coming more into line.
The only question is if an EV meets ones driving patterns.

 

Remote heat? Nope. Remote climate control only works when temperature setting is less than ambient temps. In other words, for A/C. Only.

 

And you remind me how much I miss consulting in Chico. Stayed at a hotel walking distance to the brewery.

 

Really? In our 2012 Volt we used the remote app to preheat the car quite often.

 

I'm talking about the PiP Advanced.

 

I think what you're getting at is, there are diminishing returns, so as a vehicle is made more and more efficient, the difference in efficiency between it and other vehicles that are also made more and more efficient become smaller and smaller. Especially so when comparing the same technology - eg, only so much that can be done with an ICE.

 

My local utility (Progress/Duke) no longer offers TOU pricing to new users, they will let us current TOU users be grandfathered. I invested in a smart meter which limits the amount of electricity I use during the peak charge periods which saves me around $50-70 a month by limiting the number of high energy use appliances I will have on at any given time. I find it very easy to adapt my dryer and dishwasher use to after 9PM and don't find the A/C and heater and water heater limits to be too painful until the temperatures drop to the single digits.

So investigate before making an assumption that night time charges will be more economical. Just because your neighbor has it doesn't mean you can.

 

I'm waiting for my 6.7kWh solar energy installation. Once I have a track record of its actual output, I may change to TOU (still available in Southern California Edison territory). The idea being, when solar output is maximum, any consumption from the grid will be offset by the generated power.

 

That's it. It is true for hybrids. It also holds for electrified vehicles if we consider electric motor efficiency. For example, the Leaf usually averages 4 miles/kWh of charge and can easily do 5 with gentle accerlation, 5.5 if being ultra-miserly. The Volt averages 3.5 miles / kWh and can do 4 with gentle acceleration, 5 only if keeping below 50 mph or so. The Tesla sedan averages 2.5 miles / kWh, 3 if accelerating gently and 3.5 if being really conscious of use. Difference is clear: curb weights of 3,200, 3,800, and 4,600 lbs. As the all-electric range of these vehicles approaches what would be acceptable for a gasoline-only vehicle, the efficiency falls off. Thus, the closer to a regular, efficient car any of these vehicles is, the more similar the running cost will be. Not to mention we are talking about lithium which costs about $7,500/ton and has stagnated in price increase, but not decreased.

 

My mistake. I was not aware of that fact for the PiP. Hopefully when Toyota rolls that out to the northern states that is corrected.

 

For a spreadsheet to be useful you need to put in accurate data.
May I ask where you are getting those numbers? They are quite a bit off.

It is true that the larger heavier vehicles are less efficient than the lighter ones, although not to the extremes you state.

Your conclusion that as electric vehicles approaches "what would be acceptable" the efficiency gains lessen is vague and illogical.
If this is being placed in a spreadsheet, perhaps you should have an entry for what is an acceptable range?
There are over 100,000 all electric highway capable vehicles on the roads in the USA. Over 70,000 of those are the Leaf. Those owners all find the Leaf's range acceptable to them.

Even using your numbers though, the least efficient electric using 400 Watts per mile (which I get much better than), to go 12,000 miles would take 4,800 kWh. At average US electric costs that is about $576/year.
That would buy you about 180 gallons of gas. A gas vehicle would need to get 67mpg to equal that.

Can it be done? Perhaps. But the same driver that gets 67mpg will be getting 275Wh/mile which translates to about 97mpg.

Worse case scenario you are looking at a 33% efficiency increase over the most efficient gas powered car.

 

The miles/ kWh are derived from what I have seen people post in groups. I can get 5 miles / kWh easy, but that is not normal driving.

On the spreadsheet I posted earlier, any figure can be entered for kWh / 100 miles. I put 33 in as an example average over a year. One could put 50 to estimate just cold weather or 25 for temperate. Similarly, this can be adjusted to estimate driving style.

The spreadsheet subtracts the electric miles separately from the gas miles. To estimate a Leaf, one just needs to stay below however many miles they would get from the kWh input and the kWh/100 miles.

If you look at it, I didn't try to define car types at all, it just has numbers which can be changed however you'd like to estimate.

 

For example, the EPA rates the Tesla at an average of 38 kWh/ 100 miles, Leaf 30, Volt 35, and PIP 29, so those could be put in. Those also change by model year and I'm not sure if that is just the EPA changing their mind or the cars changing.

I put in Tesla numbers for 38 / 85 vs. 50 mpg car. At 40 miles, $0.58 per day savings. With 40 miles per day + 200 additional roadtrip miles per week, yearly savings would be $360.

 

To bring this back to relevancy for the OP, I added another sheet "Compare EV" that has the Volt vs. PIP at a 20 mile daily commute using my local electric and gas prices. The Volt saves 6 cents per day.

 

Here is Volt vs. PIP fuel economy at 20 and 100 miles.

 

Will the PiP accomplish 50 mpg from cold going 8.3 miles?
I doubt it.