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CR designs testing methodologies to enable the evaluation of all comparable products in a fair and standardized way. We look at the criteria which in our judgment are most important to consumers to evaluate products in an independent and fair manner.
This quote is hilarious. CR has had an import bias for decades even after the American car manufacturers improved their quality. Everything I've ever purchased using a CR recommendation broke one month after the warranty expired. They lost my trust 3 decades ago.
 

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One thing I wasn't expecting in their clarification: They turn down regenerative braking to its lowest setting. This might seem like they're doing the same thing to both cars, but that's not actually the case...

It penalizes cars without blended brakes (like all Teslas to date) while having minimal effect on cars with blended braking (like the Bolt,) since they still get to use full regeneration when the driver hits the brake pedal.

Given that the vast majority of EV drivers I know use the highest level of regen available, it doesn't seem to be a particularly realistic assumption. The stated rationale for that decision doesn't really seem terribly reasonable to me, either.
 

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One thing I wasn't expecting in their clarification: They turn down regenerative braking to its lowest setting. This might seem like they're doing the same thing to both cars, but that's not actually the case...

It penalizes cars without blended brakes (like all Teslas to date) while having minimal effect on cars with blended braking (like the Bolt,) since they still get to use full regeneration when the driver hits the brake pedal.

Given that the vast majority of EV drivers I know use the highest level of regen available, it doesn't seem to be a particularly realistic assumption. The stated rationale for that decision doesn't really seem terribly reasonable to me, either.
Agreed. Why didn't they just leave everything at the default setting? They made sure the tires were aired up to the manufacturer's spec, why didn't they leave the manufacturer's default settings alone? The EPA range uses the default settings.
 

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I wonder if CR actually turned the Tesla's regenerative braking back to the default.
 

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One thing I wasn't expecting in their clarification: They turn down regenerative braking to its lowest setting. This might seem like they're doing the same thing to both cars, but that's not actually the case...

It penalizes cars without blended brakes (like all Teslas to date) while having minimal effect on cars with blended braking (like the Bolt,) since they still get to use full regeneration when the driver hits the brake pedal.

Given that the vast majority of EV drivers I know use the highest level of regen available, it doesn't seem to be a particularly realistic assumption. The stated rationale for that decision doesn't really seem terribly reasonable to me, either.
I minimize my regen to maximize my momentum... well, I used to when I hypermiled - don't do that any more. Maximizing regen usually hurts range on a volt, but I can see on a Tesla where the brakes are brakes, maximizing regen might be useful. You'd think with all the sophistication and autopilot they are putting into the car that they'd be able to implement blended brakes on these luxury vehicles....
 

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How does maximizing regen reduce range on a Volt? I have a gen II Volt and I drive in "L" most of the time thinking I am "preserving" range.
 

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I see the bottom line for this comparison is that the Chevy Bolt EV, with the same battery capacity and interior space for five, will be more efficient and cheaper than the Tesla Model S. That is a given, no matter how much Tesla Motors and Elon Musk complains. They have other Model S versions for more range but far more expensive, just like a Toyota Yaris can be compared with a Mercedes-Benz to carry five with the same MPG but for much more money.

But if CR wants to do a more equal comparison, they should wait for the 2018 Nissan Leaf.

As for the Bolt EV battery problem, that is a infant mortality issue, which at 1% or less is acceptable for almost any large engineering project. The problem will not cause any injuries or failures, and will be solved by October when the 2018 MY production will begin.
 

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They turn down regenerative braking to its lowest setting. It penalizes cars without blended brakes (like all Teslas to date) while having minimal effect on cars with blended braking (like the Bolt,) since they still get to use full regeneration when the driver hits the brake pedal.
Yes, but how important of an effect did this difference make to the test results? CR also stated that most of their driving during the test was at a steady rate of speed:

Our EV range test involves some mixed driving, but much of it is done by driving a constant 65 mph on highways. If drivers were to meander on rural roads at 45 mph, for example, they might get even more range.

Given much of this test was done at freeway speeds, I'd say it has exposed how mistaken are those who dismiss the Bolt on the basis of its 'inferior' aerodynamics compared to Tesla.
 

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I hope some enterprising media outlet arranges to book a big flat track like Indy and run Bolt next to an MS75 and run them side by side until one dies.

Actually it would be ideal if they could test 3 of each simeltanesouly at say 50, 60 and 70 mph.
 

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I hope some enterprising media outlet arranges to book a big flat track like Indy and run Bolt next to an MS75 and run them side by side until one dies.

Actually it would be ideal if they could test 3 of each simeltanesouly at say 50, 60 and 70 mph.
Or Ari's favorite 24 MPH. :)
 

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How does maximizing regen reduce range on a Volt? I have a gen II Volt and I drive in "L" most of the time thinking I am "preserving" range.
I spent 2 years hypermiling and can definitely say that if you minimize regen, coast like the dickens, and get lucky where slowing early allows you to opportunistically reach stoplights just as it turns green and the traffic moves, you will usually do better than staying on the accelerator to the best point to pull an L regen to stop. Momentum is king. Regen only recoups about 70% at best with losses in converting to electricity, charging the battery, then converting electricity back into momentum.

For those who love their regen paddles, it's truly a sales gimmick. I prefer the variable regen of the brake pedal and never drive in L except in mountains where it's convenient just like downshifting in an ICE vehicle. Try it for a few weeks and you may never drive in L again (except for fun).
 

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Regen paddles are definitely more than a gimmick.
If you drive around in a Bolt for a few days in L, you would know.
 

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One thing I wasn't expecting in their clarification: They turn down regenerative braking to its lowest setting. This might seem like they're doing the same thing to both cars, but that's not actually the case...

It penalizes cars without blended brakes (like all Teslas to date) while having minimal effect on cars with blended braking (like the Bolt,) since they still get to use full regeneration when the driver hits the brake pedal.

Given that the vast majority of EV drivers I know use the highest level of regen available, it doesn't seem to be a particularly realistic assumption. The stated rationale for that decision doesn't really seem terribly reasonable to me, either.
I don't think that there was any ulterior motive to dialing back regen to minimum. But, I think that C&D should redo the comparison test with regen dialed to maximum (am I describing that correctly?). Would the Bolt lose more than 15 miles in that condition? What other conditions should be imposed to better level the playing field? Should the Bolt be loaded with sandbags to increase the weight to match that of the Model S? Should the tires also be changed so that both have the same ones? Should the Model S battery be discharged to the level of the Bolt before the test? In other words, it is what it is and the Bolt EV easily out-distances the Model S 75D. This should be of no surprise since the Bolt EV is a subcompact car with a large capacity battery and the Model S 75D is a full size car.
 

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How does maximizing regen reduce range on a Volt? I have a gen II Volt and I drive in "L" most of the time thinking I am "preserving" range.
Because regeneration is not 100% efficient and is subject to charging losses. Regen doesn't preserve range. What regen does is try to recapture SOME of the energy you already spent accelerating when trying to slow/stop the car. Regeneration is just a means of reducing (but not eliminating) waste energy when you must slow the car. However if you can coast or time the lights that is more efficient than using regeneration if possible.

Example. Your at a street light. And you expend 400Wh of energy (0.4KWh) to accelerate to 50mph. If you have to stop and you do so using almost all regeneration you may recapture 300Wh of energy. So you still lost 100Wh of energy. If you used friction brakes all of that 400Wh of energy is lost. However if you coast or time the lights you loose very little energy (you loose some speed through rolling resistance and drag but this energy would be normally lost anyway if you were just simply maintaining speed). And to bring the car back up to speed will cost you very little energy. Less than you would loose using regeneration.
 

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The higher the amps you regen at, the higher % of losses, and it goes up geometrically. It has to do with how heat and resistance are related.

Keep the kW always at the lowest levels possible to get the job done, and you are the most efficient.

But running in Low, Sport, and using the paddle makes a car a LOT more fun to drive.
 
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