C&D 6 affordable EV car comparison (in-depth)

[kevm14]

From the March 2014 issue, which I just received (with an odd solicitation for a cheap Road and Track subscription attached - they must have the same publisher).

This article will eventually appear on the web but I'll comment on it now. Mileage is from a 100 mile trip. Prices are as-tested, not base. The as-tested prices aren't much higher than the base. Recall that MPGe is based on the energy contained in 1 gallon of gas, and is NOT tied to gas prices. The contenders:

Chevrolet Spark EV - $27,820 - 141hp - 400lb-ft - 2940lbs - 94 MPGe observed
Fiat 500e - $33,095 - 111hp - 147lb-ft - 2949lbs - 89 MPGe observed
Ford Focus Electric - $36,990 - 143hp - 184lb-ft - 3632lbs - 89 MPGe observed
Honda Fit EV - $37,415 - 123hp - 189lb-ft - 3230lbs - 98 MPGe observed
Nissan Leaf SL - $36,910 - 107hp - 187lb-ft - 3353lbs - 93 MPGe observed
Smart ForTwo Cabrio - $30,040 - 74hp - 96lb-ft - 2113lbs - 106 MPGe observed

The Fit was the most expensive and the as-tested price WAS the base price (no options). The Spark was the cheapest as-tested and had the cheapest base price, too.

There is actually a lot to talk about here. Specification to dissect. Driving manners to compare. As I am supposed to be working on homework, I'll keep it brief, maybe.

EVs bring a new era of ways to look at power and efficiency. For example, these cars (like real cars) have motors that vary in their RPM range, torque output and final drive ratio (they all have single speed transmissions). Additionally, they have various size battery packs (easy enough to understand as an analogy to gas tank size) but the transmission of power from the grid into the battery pack, how much SoC the system allows to be used, and the overall efficiency of the drivetrain adds variables.

I'll say up front that a senior editor was quoted that these are "cars with one-gallon gas tanks that take five hours to fill." He means in terms of energy storage. In the case of range, it's maybe more like two gallons since a significantly larger portion of the energy IN the battery can be put towards locomotive force.

In terms of straight comparison to the ICE, these affordable cars are woefully behind in terms of practicality. Evidence: they brought along a Nissan generator trailer (which is a Generac 50kW unit) towed by a Nissan Armada. You see, they already had these because of the Leaf. Enough said? No, not enough. Over the portion of this test, C&D consumed 25 gallons of diesel and 5 gallons of propane to keep the EVs charged.

In reality, you can't expect these cars to function exactly like ICE-powered cars. In use, they can be used as commuters and charged at night. On the other hand, they cost as much as a Volt (with roughly twice the EV range) but really do require another car, where the Volt doesn't. Another strong argument for the Volt (if I were to shell out low $30k's for something with EV-ness). Or maybe not, as I already have other cars. Anyway.

Battery pack size:

Chevrolet Spark EV - 21 kWh (A123)
Fiat 500e - 24 kWh (SB LiMotive)
Ford Focus Electric - 23 kWh (LG Chem) *I believe they supply the Volt's pack
Honda Fit EV - 20 kWh (Toshiba)
Nissan Leaf SL - 24 kWh (Nissan)
Smart ForTwo Cabrio - 17.6 kWh (Deutsche ACCUmotive)

What's great is they all use different suppliers. The total supply maturation process is happening right before our eyes (not just the state of the art, but who can build what, and supply where).

Let's look at range. They're pretty similar, except for two outliers. This is C&D observed range.

Chevrolet Spark EV - 66 miles
Fiat 500e - 69 miles
Ford Focus Electric - 64 miles
Honda Fit EV - 52 miles
Nissan Leaf SL - 64 miles
Smart ForTwo Cabrio - 53 miles

I should also mention that the Leaf is the only purpose-built EV here. The rest are converted in some way.

They still have city/highway ratings but due to the vehicles all having energy reclamation systems (regen braking), they are all rated better in the city than on the highway. They all got worse C&D observed mileage than their highway ratings, except the Smart.

Weight bias is also an interesting story due to the battery pack weight and placement. Take a look (%front/%rear):

Chevrolet Spark EV - 51.6/48.4 (approaching 50/50!)
Fiat 500e - 57.2/42.8 (managed the best slalom with the 2nd most frontward weight distribution)
Ford Focus Electric - 49.1/50.9 (did the giant 225/50-17s and nearly 50/50 distribution play out in skidpad and slalom? No, not really. Middle-pack for both. It's the heaviest car here.)
Honda Fit EV - 55.1/44.9
Nissan Leaf SL - 57.8/42.2 (best skidpad but middling slalom. 2nd widest tires and 2nd highest weight so that's something, if you like skidpad grip, but it won by 0.01g so it's not really an advantage in reality)
Smart ForTwo Cabrio - 46.9/53.1 (more scariness from the toy car - worst grip and worst skidpad, probably stability system limited, for safety)

Now let's look at something that the article didn't mention. The Spark has, by far, the most torque. But there is a story here. As I said at the beginning, the motors all have different RPM ranges. They are all AC permanent magnet motors (batteries store DC). Let's look at the hp and torque ratings:

Chevrolet Spark EV - 141hp @ 2000rpm, 400lb-ft @ 0rpm
Fiat 500e - 111hp @ 4000rpm, 147lb-ft @ 0rpm
Ford Focus Electric - 143hp @ 5500rpm, 184lb-ft @ 0rpm
Honda Fit EV - 123hp @ 10,320rpm, 189lb-ft @ 0rpm
Nissan Leaf SL - 107hp @ 10,000rpm, 187lb-ft @ 0rpm
Smart ForTwo Cabrio - 74hp, 96lb-ft @ 0rpm

Part of the story is that the power curve is likely pretty broad. The HP peak rpm probably doesn't tell the whole story.

But what I found kind of hilarious is two of these reflect the ICE philosophy of each respective maker. Look at the Spark. It's a lower revving torque monster. Look at the Fit. Highest peak HP rpm out of the group.

The story is enhanced by looking at the axle ratios (remember it's direct drive with a differential):

Chevrolet Spark EV - 3.17
Fiat 500e - 9.59
Ford Focus Electric - 7.82
Honda Fit EV - 8.06
Nissan Leaf SL - 7.94
Smart ForTwo Cabrio - 9.92

Let's think about this. Look at the Spark again. That 3.17 ratio is even taller than what the gas Spark would have. The rest are VERY short. There's even more. The Spark has the best highway MPGe rating at 109. Low rpm torque and tall gearing. This should sound familiar! I should also point out that the city rating is very competitive (3rd place).

Again, the article didn't discuss this, but it's very interesting. Let's look at theoretical available wheel torque at 0rpm (off the line, assuming no torque management, which they ALL probably have):

Chevrolet Spark EV - 400lb-ft * 3.17 = 1,268 lb-ft (medium tire height)
Fiat 500e - 147lb-ft * 9.59 = 1,410 lb-ft (medium tire height)
Ford Focus Electric - 184lb-ft * 7.82 = 1,439 lb-ft (tall tire height)
Honda Fit EV - 189lb-ft * 8.06 = 1,523 lb-ft (medium-tall tire height)
Nissan Leaf SL - 187lb-ft * 7.94 = 1,485 lb-ft (tall tire height)
Smart ForTwo Cabrio - 96lb-ft * 9.92 = 952 lb-ft (short tire height)

Interpret the results in accordance with the tire height, as that will be the final multiplier before the power gets to the road. Also take into account weight which would allow us to arrive at an overall torque-factor at launch. I will not crunch those numbers at this time, but here are the qualitative rankings.

Chevrolet Spark EV - 2.32lbs per wheel lb-ft and medium tires
Fiat 500e - 2.09lbs per wheel lb-ft and medium tires
Ford Focus Electric - 2.52lbs per wheel lb-ft and tall tires
Honda Fit EV - 2.12lbs per wheel lb-ft and medium-tall tires
Nissan Leaf SL - 2.26lbs per wheel lb-ft and tall tires
Smart ForTwo Cabrio - 2.22lbs per wheel lb-ft and short tires

I will rate each vehicle by my own off-the-cuff guess at launch feel taking into account these factors. So, I would wager the following:

Chevrolet Spark EV - Second worst torque ratio and medium tires = Medium launch
Fiat 500e - Best torque ratio and medium tires = Strong launch
Ford Focus Electric - Worst torque ratio and tall tires = Weak launch
Honda Fit EV - Good torque ratio but medium tall tires = Medium launch
Nissan Leaf SL - Middle pack torque ratio and tall tires = Weak launch
Smart ForTwo Cabrio - Middle pack torque ratio and short tires = Medium launch

In fact, we can just look at the 0-30 time to judge the launch proficiency (which obviously takes into account all real-world factors):

Chevrolet Spark EV - 3.2s
Fiat 500e - 2.8s
Ford Focus Electric - 4.0s
Honda Fit EV - 3.1s
Nissan Leaf SL - 3.4s
Smart ForTwo Cabrio - 3.1s

How did I do? I nailed it. Take a look.

But like gas engines, and in vehicles with a single speed, you are necessarily going to trade low speed launch for higher speed acceleration. Does that prove out? Yes. Look at the 0-60 and 1/4 mile results:

Chevrolet Spark EV - 7.9s and 16.3 @ 86mph (best 0-60 and scorching mph, it's got the highway legs of the group - second best range, third best efficiency and lowest price = win)
Fiat 500e - 8.7s and 16.8 @ 80mph (already fell behind by 60 and the Spark is going 6mph faster @ the 1/4 mile)
Ford Focus Electric - 10.1s and 17.9 @ 80mph (similar MPH due to similar power to weight but without the Fiat's launch, not good)
Honda Fit EV - 8.5s and 16.7 @ 83mph (respectable performance, good blend of launch and mph - second best efficiency but worst range and highest price - DOH)
Nissan Leaf SL - 10.2s and 17.7 @ 78mph (the Volt famously performs better as an EV than the Leaf - this is slow)
Smart ForTwo Cabrio - 9.8s and 17.5 @ 76mph (it's tiny and light, and the speed limiter kicks in at 78mph - it's a toy car)

Let's see if the horsepower to weight ranks with those trap speeds:

Chevrolet Spark EV - 20.9 lb/hp
Fiat 500e - 26.6 lb/hp
Ford Focus Electric - 25.4 lb/hp
Honda Fit EV - 26.3 lb/hp
Nissan Leaf SL - 31.3 lb/hp
Smart ForTwo Cabrio - 28.6 lb/hp

The Fit is out-performing its lb/hp in my opinion. The Smart underperforms due to what I call the motorcycle effect. The rest makes sense.

Also of interest (to me) was that the Leaf had the highest governed top speed of 94mph. The rest were around 90, mid 80s or 78 in the case of the scary-at-high-speeds Smart. The reason it's interesting is because the Volt will go 101mph in EV mode (also governed). Ha. See here: http://www.edmunds.com/chevrolet/volt/2 ... 1-mph.html

It may be interesting to throw the Volt into this specs mix. I may do that at another time. I guess I would just edit this post so it's all integrated.

So the Spark was extremely competitive in performance metrics. The fastest. The best braking. Second best skidpad. Second best slalom. And it was the cheapest. Yup, it won the comparison. I would wager that GM's R&D investment in the Volt program has paid off. That the gas Spark is not a penalty box sealed the deal, in my opinion.

[kevm14]

EPA specs. City/highway/combined, energy/100 miles, range

Chevrolet Spark EV - 128/109/119, 28kWh, 82 miles
Fiat 500e - 122/108/116, 29kWh, 87 miles
Ford Focus Electric - 110/99/105, 32kWh, 76 miles
Honda Fit EV - 132/105/118, 29kWh, 82 miles
Nissan Leaf SL - 126/101/114, 30kWh, 84 miles
Smart ForTwo Cabrio - 122/93/107, 32kWh, 68 miles
Chevrolet Volt - ?/?/98, 35kWh, 38 miles

[kevm14]

Efficiency and range as a percentage of the EPA ratings. For efficiency I used EPA combined.

Chevrolet Spark EV - 79%/80.5%
Fiat 500e - 77%/79%
Ford Focus Electric - 85%/85%
Honda Fit EV - 83%/63.5%
Nissan Leaf SL - 81.5%/76%
Smart ForTwo Cabrio - 99%/78%

The Fit observed range vs EPA estimated is way off. I wonder what the deal is. The Smart is almost exactly as efficient as promised, but status quo on the range vs estimated.

[Bob]

http://planetsave.com/2014/02/22/ev-che ... le-charge/

Of course this is far from normal use...

[kevm14]

I really like the Spark. I also like that it's $27k before tax credits. I would like to drive one and feel that 86mph trap speed. Knowing that it's not the fastest off the line but pulls 86mph it proably has a very linear feel, as opposed to some of the cars that leap off the line but only trap 80.

[Adam]

86 mph?!? I had a Camaro in high school that was about that fast.

[kevm14]

Then you should feel ashamed that an electric shoe is as fast as your pony car was. Some years later...

[Bob]

I wish the Spark EV was on sale in all 50 states so I could try one out. I believe the interior is significantly smaller than the Leaf, but maybe the greater driving enjoyment will make up for it.

[kevm14]

AW drives the Spark.

http://www.autoweek.com/article/2013110 ... dailydrive

Sweet, good old GM HVAC.

The climate control works particularly well, with rapid warm-up and an air conditioner that felt capable of cooling a Chevy Suburban. Granted, both sap some of your range, but if comfort is a priority the Spark EV will happily deliver.

Novelty factor.

The high-pitched whirr and nonstop thrust is like takeoff roll in a Learjet, and it's worth finding a straight stretch of highway and blowing a whole battery pack just doing acceleration runs. After all how much more fun can you have with two bucks worth of electricity?

This is true.

It squirms a lot at highway speeds, and the driver needs to keep both hands on the wheel and really pay attention to what he or she is doing. Sounds like a no-brainer, but here in America that requirement will likely disqualify 98 percent of the driving-age population.

Even though I left early I still hit rush hour, and spent 15 minutes idling. I suppose that's when the EV should really make sense. Sitting in traffic, you'd normally be using fuel and therefore money, I could at least rest easy in the fact that though I spent an hour in traffic, I only used the money equivalent of driving home, and probably less.

Except that the car isn't totally off. You have the HVAC system. And in an EV, the heat energy comes straight out of the battery pack. So in a moderate climate, you'd just sit there with the windows down but not so much if it's cold or hot as hell outside.

[Bob]

I have found one thing that really kills the range in the Leaf is running the heat. The draw with the A/C isn't so bad. Here in NC, that makes it a decent fit.