Yet another pie-in-the-sky look at petroleum - Jay Maynard

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Sunday, 18 September 2005


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1627 - Yet another pie-in-the-sky look at petroleum

Today's Star-Tribune has yet another look at our dependence on gasoline and proposals for what to do about it. Here's the letter I sent in reply:

David Morris's commentary on electric vehicles and alternative fuels promises a lot. His proposals fall short, though, for those of us who don't live in the city.

I drive from 20,000 to 25,000 miles a year, and 95 percent of that is on the highway cruising at the speed limit. A hybrid vehicle gains me absolutely nothing under those conditions, and a 50-mile pure electric range is completely useless when my average trip is 150 miles.

Ethanol-based fuels make no economic sense whatsoever with current pricing models. E85 (85% ethanol, 15% gasoline) has only about 2/3 the energy content of pure gasoline, by the only real-world measure that counts: fuel mileage in real cars. When regular is $2.69, and E85 is $2.64, as it is at the only station selling it in Fairmont, buying E85 is pure foolishness masquerading as environmental awareness.

Until someone manages to produce a different technology that makes sense for me and the driving I do, I'll stick with plain old gasoline, thank you.


current mood: [mood icon] cranky

(25 comments | Leave a comment)

Comments:


[User Picture]
From:michaelmink
Date: - 0000
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During the brief period early in the history of cars when electrics had a significant chunk of the market, the only really reliable paved roads were in cities, so most cars made short trips. Hence, electrics were practical. Intercity highway travel really didn't exist until after WWI, and even then, it could be an adventure.

Electrics would make sense if you lived in NYC, and only drove around NYC, for example.
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From:phanatic
Date: - 0000
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That depends on the source of the power that gets converted into chemical potential energy in the batteries.

If it comes from burning fossil fuels, you're just deferring emissions from the vehicle back to the plant. That can improve things a little bit, since the scale of the plant makes cleaning the emissions easier, but you also now take hits from the transmission losses in the electrical lines that get that power to your outlet where you have the car plugged in. It is not a really significant improvement; running our cars from burning coal instead of burning gasoline doesn't really change much, environmentally speaking.

If you want clean cars, build nuclear plants and use them to crack water into hydrogen.
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From:michaelmink
Date: - 0000
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NYC and NYS actually gets a fair-sized chunk of its electricity from nuclear and hydro (both native and imported from Quebec). It's the mid-west that tends to be heavy on the coal.
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From:phanatic
Date: - 0000
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True.

However, if you switched all the cars in NYC, let alone NYS, to electric drive overnight, you'd probably increase electrical demand to the point where those clean sources couldn't supply it all.

That said, I think electrics would be a great tech for city-bound people; there's a lot to recommend them, assuming a clean source of electricity. But hybrids strike me as just the worst of both worlds.
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From:shelbystripes
Date: - 0000
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I drive from 20,000 to 25,000 miles a year, and 95 percent of that is on the highway cruising at the speed limit. A hybrid vehicle gains me absolutely nothing under those conditions

As a hybrid owner, I can tell you definitively that this is an untrue statement. I get better highway mileage than the equivalent gas-only four-cylinder model. There are a couple reasons for this:

1) The engine is an Atkinson-cycle engine, which is more fuel efficient than an "Otto-cycle" (what 99.9% of cars here use, basically the "standard" model) gasoline engine but producing less horsepower and low-end torque. Since the electric engine produces a lot of low-end torque and provides it on demand for acceleration, the gas engine doesn't need to be able to. Thus, when you're at crusing speed, you're cruising along in an engine that produces less power, but still enough to maintain cruising speed, and thus burns less fuel. I get, real-world, 31MPG on the highway, and even the unrealistic EPA estimate for the gas-only four-banger equivalent model, which is 300lb. lighter, is less than that, so obviously it's a significant savings.

2) It doesn't matter how much highway driving you do, you probably don't realize where a hybrid will save you until you've driven one. While you're exiting the highway, you're decelerating linearly (at least, if you're a competent driver), and the gas engine shuts off. While you're cruising around at low speeds, like, looking for a parking space in a parking lot, the gas engine shuts off. If you're getting drive-thru anything (and drive-thru is being used more and more these days, for more than just food), then you're either moving slowly or sitting still, so the gas engine shuts and stays off. The hybrid actually cuts down on practically all the gas you waste while idling or putting around at low speeds in different situations.

3) Driving on a highway still involves a lot of accelerating and decelerating. You have to be able to get on and off the highway, you might get stuck behind a slower vehicle, you have to accelerate to change lanes and get around that slower vehicle, etc. Even if you do generally have wide-open spaces to drive on, when those situations come up, you probably like having the extra power on call to accelerate like that. So you have three options.

Option A is the gas-only four-banger. This gets you good fuel mileage (though as already mentioned, not quite what the hybrid gets), but rather poor acceleration, so it doesn't satisfy your desire to have some get up and go there. Option B is the more powerful gas-only model with the six-cylinder engine. This gets you the acceleration you want when you need it, but it means that at all times, whether you're accelerating, cruising, or idling, you're burning more fuel than you would with the four-banger.

Option C is the fuel-efficient hybrid, which pairs a four-cylinder gas engine with an electric motor. You get the fuel savings of a small and lean engine, plus with the electric motor to assist, all the acceleration of the six-cylinder model. (Yes, it is equivalent; my sister owns the V6 and otherwise identical model, and having driven both, they accelerate the same, and both much quicker than the base gas-only I-4 model.)

So in order to compare fuel consumption for what you want in terms of performance, it's not realistic to compare the hybrid four to the gas-only four--you should compare the gas-only V6 to the hybrid four. And the hybrid four definitely wins there; I get about 8MPG better highway than my sister does, but have the same power to accelerate when I need it.

And yes, the electric motor does kick in and assist at highway speeds. It feels like a V6 at any speed I've been willing to push it at.

A hybrid can give you the same acceleration as a bigger gas-only drivetrain while giving you the fuel economy of the leaner engine. So don't say the hybrid would gain you "absolutely nothing", since you'd be flat-out wrong.
[User Picture]
From:korgmeister
Date: - 0000
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One small question. Doesn't all this stopping and starting of the petrol-driven engine cause it to experience alot more wear than one running constantly?

AFAIK, most engine wear happens in the first few minutes, when the engine is cold.
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From:shelbystripes
Date: - 0000
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No, not really. Think about it a minute--the engine doesn't instantly cool off when it shuts down. An engine block typically stays warm for a while and it takes a while for the oil in it to trickle back down to the oil pan again--and that's got a lot to do with engine wear during your first start, when there's no oil circulated up in the upper parts of the engine yet.

However, in a hybrid, the engine's only shutting off for, at most, a couple minutes at a time, which isn't nearly long enough for 1) the engine to cool down or 2) the oil to drain itself from the upper part of the engine.

The other factor that would be considered there would be that all that stopping and starting would burn out your engine's starter quickly, but a hybrid doesn't have one, at least a traditional dinky starter like gas-only cars come with. A hybrid uses its electric drivetrain to start the gas engine, and that rather large electric engine, which is also used to propel the car and to generate electricity, is capable of handling a lot more starting and restarting than your typical dinky starter.

Oh, and one other thing to consider. Hybrids by default tend to come with Continuously Variable Transmissions; CVTs keep the engine at a steady RPM while changing the gear ratio smoothly in order to accelerate, and as such, even when you're accelerating, you just ease the engine up to a higher RPM and then keep it there, which is easier on an engine than working rapidly up and down the engine's power band as you shift gears. It is possible to put a CVT in a gas-only engine, but CVTs don't handle high-power applications that well, and are better suited coupled to the relatively low-power gas engines in a hybrid. (In my car the main electric motor is geared directly to the axle and doesn't transmit power through the transmission, and as such the CVT doesn't have to deal with that much torque going through it, just the gas engine's supply.)
[User Picture]
From:phanatic
Date: - 0000
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CVTs keep the engine at a steady RPM while changing the gear ratio smoothly in order to accelerate

If that were the case, a tachometer on a CVT vehicle would be completely noninformative.

Like all automatic transmissions, a CVT is reactive, not anticipatory. I've driven CVT cars, and 'final' engine RPM lags vehicle speed. That is to say, you give the system a throttle input, and the engine RPM changes, which changes the vehicle speed. When you reach the speed you were intending to reach, the CVT changes the ratio towards an optimum for that speed/load, and the engine RPM adjusts to the corresponding value.

It's different than a typical automatic, definitely better, but the engine does not stay at a steady RPM, especially during acceleration.
[User Picture]
From:korgmeister
Date: - 0000
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Well, you'd be worried if it did.

Still, glad to know that hybrid engines do not wear themselves out unduly from all that stopping and starting.

As for using the electric drivetrain as the starter, well that's common sense. Starter motors are just little electric motors. So if you've already got a dirty great big electric motor as part of the design it makes sense to use it as the starter.
[User Picture]
From:shelbystripes
Date: - 0000
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I suppose I could have stated what I meant better.

In a traditional engine, you're shifting, say, when it peaks at 5000RPM. So to accelerate, the engine quickly climbs to 5000RPM, then drops to 3000, then climbs to 5000, then drops to 3000 again, over the course of a few seconds. This constant shift in speed is hard on the engine.

With the CVT... to accelerate, you give the engine more gas, which brings it up to, say, 4000 RPM, and then it stays at that higher RPM while the CVT cycles through gear ratios, allowing the vehicle to keep accelerating while keeping the RPMs constant. Then when you want to resume cruising, you ease off the throttle and the engine drops back down to cruising RPM, and the CVT automatically adjusts to match.

The CVT allows you to get the same acceleration with a lower peak RPM, which is easier on the engine, and allows the engine to stay at that constant RPM while accelerating, which is also easier on the engine.
[User Picture]
From:phanatic
Date: - 0000
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I get, real-world, 31MPG on the highway

My little sister's $10k 2005 Chevy Cavalier gets, real-world, 37MPG on the highway.

It doesn't matter how much highway driving you do, you probably don't realize where a hybrid will save you until you've driven one.

That depends on the hybrid. The Prius and the Insight are rather different in that regard, because they use the gas engine differently.

So don't say the hybrid would gain you "absolutely nothing", since you'd be flat-out wrong.

Hmm.

My sister has a 140-hp all-gasoline car that gets 37MPG on the highway and cost only $10,000.

The Prius (which I assume is what you're driving, I don't think the Insight uses the Atkinson cycle and I'm not sure about the Escape or the Ion), starts at $21,000, more than double the price of her car, doesn't really offer any more power (does offer a lot more torque off the line, but it's not like she's a racer), is a lot more mechanically complex, and does have a battery pack that will have to be replaced well before the lifetime of the car is over.

I think saying the hybrid would gain her "absolutely nothing" is entirely correct.
[User Picture]
From:jmaynard
Date: - 0000
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He's driving a hybrid Ford (ewww!) Escape. If I were to buy a hybrid, it'd still have to meet the same mission profile as I have now: the ability to haul people and stuff, sometimes lots of either, but not lots of both. (If I needed to haul lots of both, I'd get a Suburban.) I refuse to deal with the Ford Motor Company, so, right now, my one choice is the Lexus RX400h - which I wouldn't mind in the slightest, but can't afford.

That's not as big an issue as it seems. By the time I get to the point where replacing my current RX300 becomes necessary, there will be more choices, and there will also be more experience with hybrids in the real world. I'm still not sure that it would do me any good, or even enough good to offset the purchase price differential - and I absolutely refuse to do it if it does not make economic sense - but there will be more information to make that decision than there is now.
[User Picture]
From:shelbystripes
Date: - 0000
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The RX400h isn't a comparable model. Instead of offering a smaller four-cylinder with a hybrid drivetrain, they offer the same V6 as in the RX330 as well as an electric assist motor. You're not going to get any benefits on the highway, and in fact should get worse highway mileage--but that's not a fault of it "being a hybrid" so much as the technology being misapplied, offered to increase performance without additional fuel use instead of actually reducing the amount of fuel used in any significant manner.

So the RX400h is one "hybrid" that definitely couldn't be recommended.
[User Picture]
From:jmaynard
Date: - 0000
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Well, if that's the case, then there is no hybrid that meets my mission requirements and that I would consider buying. Under no circumstances whatsoever will I even consider the Escape, as I'm not going to give the Ford Motor Company a third chance to screw me over without bothering with lubricants.

Maybe Toyota will offer a hybrid RAV4 designed for economy, not performance. If they do, I may look at it.
[User Picture]
From:shelbystripes
Date: - 0000
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Given Toyota's initial leadership with the Prius, I had hoped that they'd offer something better in the SUV arena than they have. Both the Toyota Highlander and Lexus SUV hybrids have the same problem I mentioned, which renders them useless in terms of improving fuel economy, and both have average fuel economy numbers in the mid-20s at best.

Other than being a Ford, there's nothing about the Escape Hybrid that doesn't meet your requirements and offer advantages over what you have now. Even if Toyota's not doing it, someone else inevitably will have to, especially with gas prices the way they are now. It's just a matter of when; hopefully that someone else will come along by the time you're ready to replace your current car.
[User Picture]
From:jmaynard
Date: - 0000
(Link)
"Other than that, Mrs. Lincoln, how was the play?"

I've got a couple of years, minimum, before I'll replace the RX300. The replacement will not be an Escape (or a Tribute, which is the same vehicle in Mazda clothing), but it might be a hybrid if folks with mission profiles like mine can back up that it's a good thing, and if the repair costs don't prove prohibitive when it's time to replace that huge bank of batteries, and if the rest of the vehicle holds up well in the real world.
[User Picture]
From:shelbystripes
Date: - 0000
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Time will tell. Though obviously there are vehicles already that meet your "mission profile", and hopefully more manufacturers will build similar vehicles. There haven't been any real reliability issues with any hybrid model that I've seen so far, and the first-generation models are old enough now to show that the technology holds up well past the 100K mark.

Of course, it's possible that somebody builds a hybrid model that constantly short circuits and breaks down and wears out rapidly, but it would be a mistake to judge the technology on that instead of merely the manufacturer. It's already obvious that it's possible to do it right; I suppose the only question for you will be whether someone who you believe can do it right (such as Toyota) will actually apply the technology in a way that's useful to you.

As a final note, replacement costs for the batteries are somewhere in the $3k range, though it's projected to drop to half that within 5 years as increased demand creates increased supply and further development of the technology, and that'll come into play well before you'd need to replace such a battery anyway. (Current hybrid models such as mine come with an 8-year, 100,000 mile warranty on the hybrid drivetrain, including in my case, the transmission.)
[User Picture]
From:shelbystripes
Date: - 0000
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Looking at GreenHybrid.com in which people keep logs of their fuel mileage, the median fuel mileage for a second-generation Prius is 48MPG. So, yes, while the car costs twice as much, it would get 10MPG more than her current car.

How are you measuring "power"? Are you just looking at horsepower numbers? Because hybrids tend to look somewhat timid there, and with the high-torque electric engine accelerate better than a gas-only engine with similar "horsepower" figures. So if you're just looking on paper and seeing an on-paper HP figure and going "that doesn't offer anything good" then you don't know what you're actually talking about, because that's not how it works.

So to say that it would offer her "absolutely nothing" is absolutely incorrect; it would be possible to argue that what it offers is not worth the up-front cost, but that still requires admitting that it does offer some advantages, which it does.
[User Picture]
From:phanatic
Date: - 0000
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So, yes, while the car costs twice as much, it would get 10MPG more than her current car.

Great.

Assume that's constant. Assume the car would last her 200,000 miles in either case. In her current car, the gas 4-banger, and $5/gallon gas prices, that's about $27,000 in gas over the life of the car, as compared to $20,800 in gas for the lifetime of a 2nd-generation Prius. I have, of course, ignored maintenance costs for the 4-banger, but everything that can go wrong with a regular car can go wrong with the Prius, and the Prius also has that big battery pack that's going to need to be replaced well before 200,000 miles anyway.

So to save less than $7,000, she needs to spend an extra $11,000. Oh, and I think she gets a tax credit of $1500. Wooooo.

So if you're just looking on paper and seeing an on-paper HP figure and going "that doesn't offer anything good" then you don't know what you're actually talking about

The astute reader, who is apparently not you, will note that I specifically mentioned something about how the electric motor delivers much more torque (which is not the same thing as 'power,' despite your implication) down low than the 4-cylinder in the Cavalier. Which would be great, if being fast off the line mattered to her.

So to say that it would offer her "absolutely nothing" is absolutely incorrect

What does it offer her, then? What advantages does it offer over her current car? Mileage that is improved to such a small extent that it won't even pay for itself over the life of the car? The ability to beat soccer moms in their SUVs off the line at the green? The lack of anticipatory control offered by a manual transmission? What, exactly?
[User Picture]
From:shelbystripes
Date: - 0000
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Your figures are wrong, though this is partially my fault for not correcting your earlier mistake already.

I noticed only after posting my previous comment that you quoted 37MPG highway for that Cavalier; the Prius is 48MPG overall, which is a real-world measure of, well, whenever the car's running. That Cavalier certainly doesn't get 37MPG city, and definitely doesn't get 37MPG sitting in the drive-thru at Jack-in-the-Box or looking for a parking space at the mall. Real-world, I would imagine the Cavalier gets around 28-30MPG (I had a stick-shift Focus that got that as a real-world average if I drove it economically, and that's a somewhat equivalent car; your numbers might be higher or lower, but not likely by much). That requires more of an adjustment to your numbers, since you're not comparing 48 to 37, but really 48 to something like 29, depending on how exactly the car is driven.

And after Jan. 1, the tax credit on a Prius will be over $2000, which is an actual dollar-for-dollar subtraction from the amount of taxes you owe, so if earns enough to pay at least $2k in taxes, she'll get that much back.

The Prius offers a 0-60 time of ten seconds flat, while that Cavalier has one at 8.8, so yes, the Cavalier is a little quicker, but not by much. And as I mentioned from personal experience, the hybrid drivetrain in my Escape provides equivalent performance across the board to the gas-only V6 model which has a higher HP rating, not just from a standing start. Accelerating to pass someone on the freeway feels the same as it does in my sister's V6. Now, I haven't had the luck to drive a Prius yet, but everything I've read from people who drive them indicates to me that it does perform similarly.

I will concede that there is something lost when using an automatic transmission. However, the Prius does, from what accounts I've seen, offer significantly higher fuel mileage with similar driving characteristics to your sister's current car, just as my Escape hybrid offered that over the gas-only V6 model. Depending on fuel prices, that may not be enough to offset the cost differential, and it is of course up to you to decide whether it's worth any potential extra cost. However, claiming it's "nothing" is different than arguing that what it does offer doesn't match your priorities.
[User Picture]
From:phanatic
Date: - 0000
(Link)
though this is partially my fault for not correcting your earlier mistake already.

What mistake? You mentioned your 31mph real-world experience for highway driving, I pointed out that real-world gasoline 4-bangers can be superior to that.

Sure, my figures are "wrong." They're based on very questionable assumptions, like a 200,000 mile lifetime for the car, and $5 gasoline.

That requires more of an adjustment to your numbers, since you're not comparing 48 to 37, but really 48 to something like 29, depending on how exactly the car is driven.

She lives in a rural area, where most driving is closer to 'highway' than to 'city.' Median, she gets about 32, and a Prius would get less than 48, probably about 44.

$31,250 in gas (assuming $5/gallon, remember, which is a quite unrealistic assumption, but I'm really trying to favor your claims), vs. $22,727.

So *now* she's just about breaking even, if you include the tax credit. And if we try to make my numbers less "wrong," with, say, a 160,000 mile lifespan and $4.00 gas, then that gap shrinks rapidly.

However, claiming it's "nothing" is different than arguing that what it does offer doesn't match your priorities.

You keep saying that, but you also keep failing to point out what it *does* offer *her*. So, what exactly do you think it offers her? The wonderful opportunity to double her up-front costs for the chance to possibly break even on net costs over the life of the car, if we don't factor in a $3000 battery change?

What you're claiming is that, since hybrids have something to offer some people, they have something to offer everyone</i
[User Picture]
From:jmaynard
Date: - 0000
(Link)
And if you accept the 48 MPG rating for the Prius, and factor in the $2K tax credit, and leave the other assumptions alone (200K mile lifetime, $5/gallon gasoline), and ignore the $3000 battery replacement cost (much less assume it will only be needed once over the lifetime of the vehicle), as well as ignoring any other maintenance needed on the hybrid drivetrain over and above the comparable conventional drivetrain...

You make about $1400. Change any of the assumptions (say, go back to a less unreasonable $4/gallon), and you're back to losing money.
[User Picture]
From:shelbystripes
Date: - 0000
(Link)
I'm claiming that hybrids have something to offer everyone. I'm not claiming that something outweighs other disadvantages, just that it's there. You're trying to say that since the advantages don't outweigh the disadvantages, there are no advantages, which is pretty twisted logic.
[User Picture]
From:phanatic
Date: - 0000
(Link)
You're trying to say that since the advantages don't outweigh the disadvantages, there are no advantages

No, I'm not.

Here, let's read for content, and go back and look at my initial response to you:

My sister has a 140-hp all-gasoline car that gets 37MPG on the highway and cost only $10,000.

The Prius (which I assume is what you're driving, I don't think the Insight uses the Atkinson cycle and I'm not sure about the Escape or the Ion), starts at $21,000, more than double the price of her car, doesn't really offer any more power (does offer a lot more torque off the line, but it's not like she's a racer), is a lot more mechanically complex, and does have a battery pack that will have to be replaced well before the lifetime of the car is over.

I think saying the hybrid would gain her "absolutely nothing" is entirely correct.


You have offered nothing to contradict this. In other words, you have presented nothing about a hybrid vehicle which would gain her anything over the car she has, except double the initial expense to have a chance to break even on that cost over the lifetime of a car, given some *very* generous assumptions.

I'm not claiming that something outweighs other disadvantages, just that it's there.

Great. So what is it, then? Because you still haven't come up with anything.

[User Picture]
From:shelbystripes
Date: - 0000
(Link)
I guess I see what you're saying, it's an issue of semantics. My point is, you're saying that a vehicle with increased fuel economy and the same performance offers nothing, when it does offer something (that just-mentioned increase in fuel economy with the same vehicle performance), just that in her/your judgement, what it offers isn't likely to be worth the additional up-front cost.

You keep saying "nothing" when what you mean is "something I don't personally consider a good value".

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