GM Recalls 64K Chevy Volt Cars Due To Possible Carbon Monoxide Risk

“And there is no buffer and there is not time.”

Yes, there is a buffer. You know, for someone who seems to enjoy hating the Volt so much, you really should learn about how it works.

You see, after the 40-mile battery is “depleted” and it switches over to gasoline mode, the battery pack is not actually at zero charge internally, but is actually at around 20% charge. When in gasoline mode and going up a steep hill, it will use a little of that 20% in order to keep the electric motors powered and helping the engine. Once the hill is not so steep, it uses the engine to refill the buffer.

Now, I'm open to you providing links to other real-world examples of people going into Propulsion Power Reduced Mode (PPRM), but the only example we have found so far was when someone climbed 2,000 feet in 6 miles, which comes out to about a 6.3% average grade. (Average is what matters since the buffer serves to smooth over temporarily increases and decreases in grade.)

However, the example you provided was an extremely shallow grade: 2,500 feet over 90 miles, or 0.5% average grade. For such a shallow grade, the engine has more than enough power to not only maintain constant high speeds, but also to recharge the battery.

So even your conjured surprise-free-lift-tickets-after-going-to-the-airport scenario would not end up with you in PPRM.

“Tell me why I’m wrong and cite the appropriate section of the constitution.”

Well, I already explained in my previous post how EV subsidies benefit the common good. As far as where the Constitution supports that, you only have to look as far as the first sentence:

We the People of the United States, in Order to form a more perfect Union, establish Justice, insure domestic Tranquility, provide for the common defence, promote the general Welfare...

Ahhh...so the preamble to the constitution, a document crafted to protect the people from an oppressive government, starts right out of the gate authorizing legalized thievery from the people. You may just be on the wrong site, comrade.

Now, I have no idea where you are getting your numbers (2,500 feet?). It is well known that the approach to the Eisenhower tunnel is 6%...and btw its 6,000 feet above Golden. Once again, just one very small piece of the trip matches your ‘worst case’ scenario of cruising in Arizona.

“Now, I’m open to you providing links to other real-world examples of people going into Propulsion Power Reduced Mode (PPRM),”

30 seconds on Google:

http://gm-volt.com/forum/archive/index.php/t-19697.html

http://voltpowerreduced.blogspot.com/

Now lets do some math. If a Volt has a 38 mile range, and it has 20% of battery charge left, it has 8 miles of charge left....and presumably that is 8 miles of flat land driving. How on earth is it going to get from Golden, Co and even up to the Eisenhower tunnel, 40 miles away? You certainly won’t be doing it on electric power.

“Now, I have no idea where you are getting your numbers (2,500 feet?).”

Well I posted a link in my #79 post. Here it is again. The net elevation change from Golden to Vail is 2,500 feet. However...

“It is well known that the approach to the Eisenhower tunnel is 6%...and btw its 6,000 feet above Golden. Once again, just one very small piece of the trip matches your ‘worst case’ scenario of cruising in Arizona.”

...there does seem to be a high point at the Eisenhower tunnel, so lets do the calculation again based on that. The distance from Golden to the Eisenhower Tunnel is 48 miles. With a climb of 6,000 feet, that is still a relatively shallow 2.4% average grade. Also, there would be more than enough buffer to take care of any temporary 6% grades, since you would have engaged Mountain Mode when you started the climb in Golden. (Mountain Mode would have used the engine during the shallow parts of the climb to charge the battery up to 35%.)

The links you provided do not give enough information to indicate what kind of grade caused PPRM. So far, the best example we have is on a prolonged 6% grade.

“Now lets do some math. If a Volt has a 38 mile range, and it has 20% of battery charge left, it has 8 miles of charge left....and presumably that is 8 miles of flat land driving.”

No, no, no. The 20% battery charge is when the battery has zero miles remaining and has switched to gasoline mode. Like I said, you need to do a little more reading up on the Volt. You can't charge above roughly 85% and it switches to gasoline at around 20%, so the Volt never uses the entire 100% of the battery. If it did, it would probably have a 60 mile battery range.

“How on earth is it going to get from Golden, Co and even up to the Eisenhower tunnel, 40 miles away? You certainly won’t be doing it on electric power.”

I think you are starting to confuse yourself. The entire premise, of this entire example, as you laid out, is that we have already driven through the 40-mile battery range after driving to the airport and are now using the gasoline engine. Yes, the electric motors are still being used, but the engine is running the entire climb from Golden to Vail.

“temporary” 6% grades, huh?

Ok, since you’ve obviously never driven in the Rockies, here it is: the last 8 miles approaching the Eisenhower tunnel is at 6%. So in your head, the 6% grade for 6 miles in Arizona puts the car in PPM, but a 6% grade for an even longer distance would not. Got it.

But wait..there’s more. You are of the belief that the Volt will be able to steadily charge itself while, you know, climbing a mountain....and be fully charged to make this trip. You do understand that the very existence of Mountain Mode proves you are wrong. No, an 89 hp engine powering a 74 hp electric motor to push a 3,800 lb car is not going to have enough power to recharge the batteries in any meaningful way....when going up a sustained grade for 30-40 miles.

Again, if this were true, there wouldn’t be mountain mode. Now I want you to read GM’s propaganda very carefully. Yes they have tested going up Pike’s Peak...and in fact GM claims the Volt can go up ‘any mountain’ in the US. Are you starting to understand why Mountain Mode exists? A Volt with a depleted battery can not make it up Pike’s Peak, or ‘any mountain’. So as soon as I interject one little tidbit of real world driving...starting up a mountain with no advanced notice, its over. If the Volt could do that ‘like a normal car’, there would be absolutely no need for Mountain Mode, would there?

Now please explain this:

“The links you provided do not give enough information to indicate what kind of grade caused PPRM.”

So what? SO WHAT?!?! A Volt owner reports going into PPRM, and pegging out at 55 mph...and it doesn’t matter since you don’t know how far a grade he was going up? This is the heart of the matter. I continue to say the Volt is not ‘like a normal car’...and this is a perfect example. It doesn’t matter how far a grade he was going up...do you think he was climbing Mt Everest? He was on a road...a r-o-a-d....cars should be able to go on roads, even if toys can’t.

“’temporary’ 6% grades, huh? Ok, since you’ve obviously never driven in the Rockies, here it is: the last 8 miles approaching the Eisenhower tunnel is at 6%. So in your head, the 6% grade for 6 miles in Arizona puts the car in PPM, but a 6% grade for an even longer distance would not. Got it.”

Yep. Since it is the last 8 miles that is the steepest, the Volt would have built up more than enough buffer in the first 40 miles by using Mountain Mode (MM).

“But wait..there’s more. You are of the belief that the Volt will be able to steadily charge itself while, you know, climbing a mountain....and be fully charged to make this trip. You do understand that the very existence of Mountain Mode proves you are wrong. No, an 89 hp engine powering a 74 hp electric motor to push a 3,800 lb car is not going to have enough power to recharge the batteries in any meaningful way....when going up a sustained grade for 30-40 miles.”

Here is where you are using your common tactic of conflation. You are conflating the steep part of the journey which is just the last 8 miles, with the shallow part of the journey, which is the first 40 miles. By my calculation, if the last 8 miles is 6% grade as you say, and the overall 48-mile trip from Golden to the Eisenhower Tunnel is an average of 2.4% grade, that would mean that the first 40 miles is only a 1.7% grade. That is a very shallow grade and the 89 HP engine would have no problem maintaining high speeds and have enough power left over to charge the battery that entire time as well. Once you got to the last 8 miles with the steeper 6% grade, MM would have built up the battery charge to 35% which would be more than enough buffer to prevent the PPRM situation that the Arizona example encountered.

Do you understand now?

“Again, if this were true, there wouldn’t be mountain mode. Now I want you to read GM’s propaganda very carefully. Yes they have tested going up Pike’s Peak...and in fact GM claims the Volt can go up ‘any mountain’ in the US. Are you starting to understand why Mountain Mode exists? A Volt with a depleted battery can not make it up Pike’s Peak, or ‘any mountain’. So as soon as I interject one little tidbit of real world driving...starting up a mountain with no advanced notice, its over. If the Volt could do that ‘like a normal car’, there would be absolutely no need for Mountain Mode, would there?”

So I've shown that even in your contrived example (that only probably 1 in 10,000 Americans would run into, once in their entire lives), that even that would not result in PPRM. So you are going to have to come up with an even more contrived example that would be even more rare. And even then, in that extraordinarily rare scenario, the worst case would be that you are limited to 55 mph during a few miles of your trip going up a steep grade.

“So what? SO WHAT?!?! A Volt owner reports going into PPRM, and pegging out at 55 mph...and it doesn’t matter since you don’t know how far a grade he was going up? This is the heart of the matter. I continue to say the Volt is not ‘like a normal car’...and this is a perfect example. It doesn’t matter how far a grade he was going up...do you think he was climbing Mt Everest? He was on a road...a r-o-a-d....cars should be able to go on roads, even if toys can’t.”

Thanks for bringing up a perfect example of how being educated about the Volt solves these problems. This specific example you are citing, which is in this forum thread that you linked to, the driver is asking people about a situation in which he experienced PPRM. If you read the forum thread, you will see in the third post that the driver did not realize that in order for MM to work you have to enable it beforehand! Here is the quote:

Should I have used “MM” BEFORE I got to the hill or as I was going up?
I had been running aprox 75 miles on “gas” “normal drive mode” prior to going uphill.
Cheers

So even in this example that you provided, the only reason PPRM happened is because the driver did not understand the features of his car.

Now, I understand this is a new technology and it takes some getting used to. There will be some learning experiences for both drivers and for internet posters alike. That is why I don't have a problem explaining it to people.

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