Chevrolet Spark EV

[EVNow]

EPA shows LEAF at 75 miles of range an the SparkEV at 82 miles of range http://www.fueleconomy.gov/feg/Find.do?action=sbs&id=32154&id=33558&id=33640

Yes - EPA really screwed up with this. Only on two Japanese cars they have implemented this weird idea of averaging 80% and 100% charge ranges (only on Leaf & RAV 4 EV). They don't do it for S (which has a similar range and normal charge modes).

Essentially, EPA range is no longer apples to apples comparison.

 

[fengshui]

It's sad to see a "Car Pro" get hoodwinked by Chevy's 400 lb-ft of torque number. Yes, the engine has that much torque, but they then run it through a much smaller gearing than other EVs, so wheel torque isn't that much more than a LEAF, and it's not in the same league as the Tesla or Ferraris they mention.

 

[ItsNotAboutTheMoney]

Yes - EPA really screwed up with this. Only on two Japanese cars they have implemented this weird idea of averaging 80% and 100% charge ranges (only on Leaf & RAV 4 EV). They don't do it for S (which has a similar range and normal charge modes).

Essentially, EPA range is no longer apples to apples comparison.

That's because the Model S got in before the new rules and now they've said go for it and changed it to a slider. By taking away a recommendation, they prevent the EPA from lowering the rating.

 

[stopcrazypp]

That's because the Model S got in before the new rules and now they've said go for it and changed it to a slider. By taking away a recommendation, they prevent the EPA from lowering the rating.

I also suspect the change to a slider is specifically to address this EPA policy. It makes it so the EPA doesn't have two modes to average.

 

[JRP3]

Spark ad:

 

[qwk]

More GM lies. If you measure the torque on both cars the same(at the wheels would be easiest since that is what is put to the pavement), I bet the Ferrari torque would be double what the Spark has.

GM is the king of misleading when it comes to advertising.

 

[scottf200]

It's sad to see a "Car Pro" get hoodwinked by Chevy's 400 lb-ft of torque number. Yes, the engine has that much torque, but they then run it through a much smaller gearing than other EVs, so wheel torque isn't that much more than a LEAF, and it's not in the same league as the Tesla or Ferraris they mention.

Peter Savagian
May 1, 2013 at 12:21 pm

I am the general director for Electric Drives and Electrification Systems Engineering at General Motors. I need to disabuse you of the mistaken notion that this motor has less than 400 ftlb of Torque. The Spark EV motor is designed and manufactured by GM.

This motor makes 540 Nm (402 ftlbf) of Torque at stall and out to about 2000 rpm. This is not gear- multiplied axle torque, but actual motor shaft torque.

The very high torque is motor performance that we are very proud of, and customers will notice the difference: (It has a gear reduction of 3.18 to 1, so the axle torque is the product of these two). This is a very low numerical reduction ratio, which has several great benefits – 1) Feels much better to drive. 3.18:1 is less than half of the reduction of all other EVs. This makes for extraordinarly low driveline inertia, less than 1/5 of the driveline inertia of the Nissan Leaf and 1/4 that of the Fiat 500 EV. Their cars feel like you are driving around in second gear all day long; ours feels like fourth gear. 2) Lower gear mesh, spinning losses, and lower high speed electromagnetic losses mean very high drive unit efficiency. The Spark EV efficiency from DC current to delivered Wheel torque is 85% averaged over the city driving schedule and 92% when averaged over the highway schedule. This is the highest in the industry, and that is one of the reasons why the Spark EV sets the benchmark for most efficient car.

Google search turned up:
Peter Savagian (suh vah’ jhin) - General Motors
SAE International -- mobility engineering
OEM Reports: The Chevrolet Spark EV 1ET35 Drive Unit - Performance, Efficiency, and Drive Quality

Pete serves as Engineering Director of GM’s Electrification Architecture and Electric Motor Release Center. For the past 12 years, in various roles, he has managed product development and advanced engineering for GM’s hybrid systems, including hybrid architecture development, electric drive component development, systems engineering, systems analysis, and control algorithm development. Pete has worked on electric vehicle systems since 1990. Prior to his current assignment, Pete was Chief Engineer for GM’s EV1 Electric Vehicle Drive Unit and Power Electronics at General Motors and at Delco Electronics. In the past, he has worked at Hughes Aircraft Company and Sundstrand Aviation in various engineering roles.
Pete holds a BS in Mechanical Engineering from the University of Wisconsin, a MS in Operations Research Engineering from the University of Southern California, and an MBA from Duke University.

 

[kilpatds]

Er? A motor's torque is measured at the motor. If the Spark has 400 ft.lb there, then it's got that much torque. That's not a lie.

The Lie is that anyone should care about torque. Care about power.

 

[fengshui]

It's not a lie, certainly. It's just misleading. Many enthusiasts use torque as a proxy for acceleration. That works as long as the cars you are comparing have roughly the same gear ratio and run in roughly the same RPM range. EVs have a wide range of gear ratios and RPMs. The Spark EV has a high torque engine, but it runs at a low RPM and through a lower gear ratio. As such the actual torque and power available at the wheels just isn't as high as the Ferrari they're comparing to. The high torque engine in the Spark EV does have benefits, and it probably feels pretty fast off the line compared to a LEAF, but it's not Ferrari or Tesla class.

 

[rolosrevenge]

This will be solved by a simple drag race between any Tesla and a Spark.

 

[qwk]

Er? A motor's torque is measured at the motor. If the Spark has 400 ft.lb there, then it's got that much torque. That's not a lie.

The Lie is that anyone should care about torque. Care about power.

The commercial doesn't say motor torque, it says MORE torque than a Ferrari. One can measure torque at any point in the drivetrain, although the only torque that matters is the stuff that is put to the pavement.

Peak power doesn't tell you much either(what manufacturers advertise), its the power under the curve that matters. In the end, the Spark has little more performance than the Leaf. It's definately no breakthrough, even though GM portrays it as such.

- - - Updated - - -

This will be solved by a simple drag race between any Tesla and a Spark.

Or at least a back to back dyno run of each.

 

[JRP3]

To be fair published torque numbers are almost always at the motor, not the wheels. Yes it's misleading to compare it to a Ferrari. I'd like to see someone put at least a two speed gearbox in the Spark, you'd have a real sleeper.

 

[scottf200]

In the end, the Spark has little more performance than the Leaf.

Interesting. I thought 0-60 was like a full second faster. That's more than a 'little'. Obviously, ~7.6 for the Spark is not a race car but for a sub-$30K car it is a good selling point and if it helps sell to a bigger audience then great.

 

[WarpedOne]

If you measure the torque on both cars the same(at the wheels would be easiest since that is what is put to the pavement), I bet the Ferrari torque would be double what the Spark has.

And even torque at the wheels is not directly comparable between the cars.
What one feels is the acceleration hence acceleration is the ultimate benchmark, it is what really counts. It comes from "propulsive" force divided by total weight.
One must first translate motor torque into wheel torque, then he must look at wheel size to compute that 'propulsive force' and finally it needs to be divided by vehicle and driver weight.
This result is then directly comparable between the cars.
This is the reason Lotuses are ultimate sports cars even though they are relatively low powered (low torqued).

Motor torque is trivia, interesting but mostly useless data. Show acceleration chart!

 

[SwedishAdvocate]

I'd say GM just redefined an empty boast with that Spark ad.

 

[60TTuC]

2014 Chevrolet Spark EV [w/video] First Drive - Autoblog

 

[ggies07]

2014 Chevrolet Spark EV [w/video] First Drive - Autoblog

"General Motors admitted that the Spark was not designed with an EV drivetrain in mind"

"Getting the Spark EV from concept to reality didn't take long – just three years – thanks to lessons learned from the Chevy Volt"


And they are defending it as their "grand EV product"? hahahaha. Again, it must be said, good job GM. [/sarcasm]

 

[mnx]

Autoblog seemed to like it a lot. I'd love to drive one of these and the i3 when they are available. (Of course I said the same thing about the Leaf and Volt, and I've yet to drive either of those)...

 

[wycolo]

While the Fiat 500 and the Leaf are RPMing like crazy from launch, the SparkEV 'torques' off the line and @41.5 mph is just entering its efficiency range. This is what the 3.2 final ratio means, vs ~8.0 for the buzz-bombs. Major coup for GM designers and for drivers, a whole new approach. Can't wait to drive one. Should be more Tesla-like.
--

 

[Dave EV]

While the Fiat 500 and the Leaf are RPMing like crazy from launch, the SparkEV 'torques' off the line and @41.5 mph is just entering its efficiency range. This is what the 3.2 final ratio means, vs ~8.0 for the buzz-bombs.

Uh, a high torque low RPM motor is just a different way to accomplishing the same thing. The biggest benefit is lower rotational enertia. Efficiency curves of a motor's operational range is going to be similar regardless of the operating range. All EVs "torque" off the line and all the single speed production EVs also hit max power somewhere between 30-50 MPH - the Spark EV is no different.

The real reason the Spark EV has better performance is because of it's light weight (<3000 lbs) and high power (105 kW) relative to the other EVs. The power is most likely partially possible because of the A123 batteries they use which are very good at handling high power applications - but then again the Volt has similar power output (111 kW) but with a smaller LG pack so the Spark EV pack doesn't even have to work as hard as the Volt's EV pack. I bet the Spark EV batteries will last a long, long time.

I bet GM could have gotten even more power out of the Spark if the chassis could handle it...

- - - Updated - - -

While the Fiat 500 and the Leaf are RPMing like crazy from launch, the SparkEV 'torques' off the line and @41.5 mph is just entering its efficiency range. This is what the 3.2 final ratio means, vs ~8.0 for the buzz-bombs.

Uh, a high torque low RPM motor is just a different way to accomplishing the same thing. The biggest benefit is lower rotational enertia. Efficiency curves of a motor's operational range is going to be similar regardless of the operating range. All EVs "torque" off the line and all the single speed production EVs also hit max power somewhere between 30-50 MPH - the Spark EV is no different.

The real reason the Spark EV has better performance is because of it's light weight (<3000 lbs) and high power (105 kW) relative to the other EVs. The power is most likely partially possible because of the A123 batteries they use which are very good at handling high power applications - but then again the Volt has similar power output (111 kW) but with a smaller LG pack so the Spark EV pack doesn't even have to work as hard as the Volt's EV pack. I bet the Spark EV batteries will last a long, long time.

I bet GM could have gotten even more power out of the Spark if the chassis could handle it...