Hybrid vs Diesel

john1701a · June 2004

> The Camry is significantly larger than the Prius

My brother has a 2003 Camry. The word "significantly" is clearly not fitting. Choose another... or just point out the actual feature/dimension you are talking about.

Perhaps you mean length of the vehicle.

JOHN

bamacar · June 2004

Shoulder room (a key feature to me as already stated above) in rear Prius - 52.9 in. Camry - 56.7 in. Town Car - 60.3 in

Yes the Camry is closer to the Town Car than the Prius on rear shoulder room. Significant is a fitting word. Yes, no doubt.

The Camry has about as much more interior cubic feet compared to the Prius as the new Prius had compared to the old Prius. Seems most of you said that was a "significant" increase in size and that was even on your website. Front shoulder room and rear headroom are other areas that are larger by a noticeable margin.

usbseawolf2000 · June 2004

What happens when vegetable oil get cold? It turns solid white stuffs right? Do I see a compromise? It won't take off like HSD since HSD offer advantages without virtually any compromise.

And regarding about fuel efficiency, HSD is more fuel efficient than any diesel engine on the market, as I've been saying all these time. Here is the confirmation.

Toyota Hybrid Synergy Drive Takes Top Honors in Four Categories:
- International Engine of the Year 2004
- Best New Engine
- Best Fuel Economy
- Best Engine 1.4-liter to 1.8-liter

http://biz.yahoo.com/prnews/040526/sfw068_1.html

Dennis

bamacar · June 2004

Good wins, but not the best fuel economy one. The results must be very subjective and not objective. The Prius beat the Insight engine and 4 others for best fuel economy. Funny the objective numbers say the Insight engine has the better fuel economy. Sounds like good marketing fodder, but not much of a independent confirmation.

usbseawolf2000 · June 2004

Where did you get subjective and objective numbers? The results are very clear. Insight took the 6th place behind BMW Diesel.

Toyota Hybrid 1.5-litre (Prius) 375

Honda 1.3-litre IMA (Civic) 153

Fiat-GM Diesel 1.3-litre (Panda, Punto, IDEA, Doblo, Opel/Vauxhall Agila, Corsa, Suzuki New Ignis) 139

Volkswagen Diesel 5-litre (Touareg/Phaeton) 75

BMW Diesel 3-litre (330d, X3, 530d, X5, 730d) 65

Honda 1-litre IMA (Insight) 58

http://www.ukintpress.com/engineoftheyear/winners/bestfuel.html

56 judges from 24 countries across five continents is not independant?
http://www.ukintpress.com/engineoftheyear/judges04.html

Dennis

bamacar · June 2004

Best fuel economy- which is defined by MPG not somebody voting. What if they had voted for the Hummer? Would that have been objective evidence for the best fuel economy of any engine or just shown subjective stupidity?

So the Insight engine finished 6th place behind the first place Prius for best fuel economy despite the fact that it has better fuel economy. Makes sense to me as long as you throw out logic.

moparbad · June 2004

The system includes a heater to maintain liquid state of the fuel.
Do you see this a compromise? What happens in the winter to a hybrid? Is a heater turned on? What happens to batteries in cold weather? Reduced performance. Do I see a compromise.

It is clear to me that some individuals are not interested in promoting fuel efficiency, alternative fuels and improved use of energy as their interest is a single one of hybrid and Prius.

Such narrow mindedness will only lead to failure.

john1701a · June 2004

> What happens to batteries in cold weather? Reduced performance.

That is NOT true.

In fact, exactly the OPPOSITE happens... INCREASED performance!

Capacity is reduced. But since you virtually never dip below 40% anyway, reaching 0% is totally a non-issue. Remember, deep-discharging shortens the battery-pack life. So the system will sacrifice gas rather than ever letting that happen.

The benefit of the cold, besides reducing resistance, is the fact that cooling is no longer a concern. So in extreme cold, the electrical abilities are enhanced. It's pretty sweet! The system actually allows greater AMP draw than it does in warm weather.

So there!

JOHN

moparbad · June 2004

John, Why do you make the statement below? quote from John's webpage-The extreme cold only forced the MPG down to around 40 during the winter. Last summer, I averaged 50 MPG the entire season. Now in my 2004 Prius, the winter only pushed the MPG down to around 45. And with the warmer temperatures (finally) and the car broken-in, it's averaging 52 MPG.-end

You state that increased performance is achieved with cold temps in #519 and the exact OPPOSITE elsewhere. Which of your statements is NOT true?

moparbad · June 2004

quote John- Prius is delivering real-world averages higher than Jetta TDI, a comparable sized diesel.-end

There are people obtaining 60 mpg with Jetta TDI. What real world avgs. were you referring too?

My point is not too discredit the Prius. Any car obtain 40 mpg is a move forward. My point is that John is anti-diesel, not just pro-hybrid. Read his weblog and you will understand more of his comments here.

Diesel is a viable option as are hybrids to improve mpg of vehicles and decrease oil dependence.

usbseawolf2000 · June 2004

The award goes to the engine, not the car. Best Fuel Economy category from International Engine of The Year.

The car can be any size with any number of seating capacity/functionality. Why don't you read and find out what the award is all about and how judges decide instead of making up your own idea/logic of an award?

"What if they had voted for the Hummer?"

Nope, will not happen. Read the rules.

Dennis

usbseawolf2000 · June 2004

"The system includes a heater to maintain liquid state of the fuel."

Ouch, that's gonna use a lot of energy just to maintain the fuel at a usable state.

"It is clear to me that some individuals are not interested in promoting fuel efficiency, alternative fuels and improved use of energy as their interest is a single one of hybrid and Prius."

Who are you referring to? If it is me, come to me directly without sprewing indirectly on other board as well. It's okay to disagree with me but I think you are more on the attacking side. If you have more information about diesel or other alternative fuel, please educate us and clear the myths. It will be up to the readers, including me, to decide which technology is right for them.

Dennis

bamacar · June 2004

I have read it, and it is illogical. Either change the name of the award or award the best fuel economy "engine" instead. A diesel bus engine that can carry fifty people is a much more of an efficient system than a Prius engine. Otherwise the "most fuel efficient engine" is inappropriately named. If you respect this award so much, do you think the massive diesel engine in the VW Toureg is really that much more effiecient than the Hybrid in the Insight? If so, the rest of us will "understand" your position but not the logic.

john1701a · June 2004

> performance

Changing definitions, eh?

All along I've been complaining that the word "performance" should not mean acceleration. Now when it is suddenly to your benefit for "performance" to mean efficiency, you accept my complaint.

Too bad, it won't work.

The reference and original statement was to the battery, not MPG. So your sudden shift to including efficiency doesn't apply anyway. Should I repeat the quote again?

Explain how "battery" applies to MPG?

Remember, the real reason efficiency is lower in the winter is due to winter-formula gas being less efficient, much longer warm-up times, needing to run the heater to keep you warm, driving times increasing, cold air being more dense, rolling-resistance higher pushing through snow, etc.

JOHN

john1701a · June 2004

> What real world avgs. were you referring too?

The HYBRID ROAD-RALLY included a Jetta TDI. On that 1,200 mile trip, the MPG for the diesel was less than the Classic Prius. (So obviously, the 2004 would do even better.) That data was quite real-world.

Remember, you must compare AUTOMATIC to AUTOMATIC. Yes, we know a manual-transmission will do better. But since so few in the United States wants that type, it can't be portrayed as a solution for all.

> My point is that John is anti-diesel

You can say that again.

Show me a diesel capable of achieving a SULEV emission rating or better, then we'll talk. Until then, they are way to dirty to be considered a realistic solution.

> Diesel is a viable option as are hybrids to improve mpg of vehicles and decrease oil dependence.

The primary goal of Prius is to reduce emissions, not increase efficiency (that's secondary). I am unwilling to sacrifice clean for MPG when technology like HSD clearly shows that it isn't necessary; you can have both.

JOHN

usbseawolf2000 · June 2004

"I have read it, and it is illogical....A diesel bus engine ...."

Then read it again more carefully! This is what it said,
"To qualify for inclusion in this Award Category, an engine must have been housed in a passenger car... "
I think I am just wasting time since it is too hard to acknowledge.

"If so, the rest of us will "understand" your position"

My position is having no position, sort of like Bruce Lee's martial art philosophy. I don't claim to know everything but I can find out and learn. To do that, I acknowledge and accept if something makes sense. I look beyond marketing hypes and PR spins. With all the choices we have today, I strongly believe that HSD is the way of the future.

Three Diesel engines are in top 6 best fuel economy engines. Gas Electric Hybrids own the top two positions, which is consistent with what I've been saying. Gas electric hybrids are more fuel efficient and cleaner(lower emission) than Diesel of any flavor.

Dennis

moparbad · June 2004

Remember, you must compare AUTOMATIC to AUTOMATIC. HA HA! Very funny.
No, I do not have to compare automatic to automatic. You compare automatic to CVT only to omit the significantly higher mpg of the manual. Most of the TDI are sold with manual by the way. Example is 50 mpg highway EPA rating with 5 spd manual vs. 44 mpg highway with automatic. And these are only EPA ratings and we all know that real world mpg varies from the EPA estimate.

Hybrid-Road Rally.- That is a real credible source of non-biased diesel info.!

john1701a · June 2004

> Most of the TDI are sold with manual by the way.

That was my point too!

> No, I do not have to compare automatic to automatic.

Then don't imply that your data is applicable to the 90% of us that do *NOT* want to have to shift. Leaving out that key information is quite misleading... just like how diesel MPG absolutely plummets in stop & slow traffic, the very situation where hybrids shine.

JOHN

john1701a · June 2004

> Hybrid-Road Rally.- That is a real credible source of non-biased diesel info.!

It wasn't actually a "hybrid" rally, but for the lack of a better name that's what we used.

In reality, the goal was to prove both hybrid & diesel could outperform a monster-size SUV. The diesel was very much part of the presentations we provided, just look at all the photos.

JOHN

moparbad · June 2004

quote John-The primary goal of Prius is to reduce emissions, not increase efficiency (that's secondary).-end

Miles per gallon is the reason people are buying hybrids. Not low emissions. Miles per gallon is why people buy diesel passenger cars. That is my conclusion. Different opinions are welcome.

john1701a · June 2004

> Different opinions are welcome.

You can't have an opinion about an implemented design. The way it operates is a fact, something the engineers specifically decided on.

Yes, the reason for buying can be an opinion. But it does not change the way the vehicle operates.

JOHN

bamacar · June 2004

I am also wasting my time as it is "all" about the application. An engine on a shelf is not what it is about. It is in the practical application ie. can we as consumers buy it. The Insight per the EPA has the highest MPG of any car available (should win this award until that changes). You still did not explain why the Hybrid engine in the Insight is has worse fuel economy than the 3 diesels ahead of it. The award is about marketing and popularity, but lets end the discussion here and agree to disagree.

moparbad · June 2004

http://lfee.mit.edu/publications/PDF/el00-003.pdf
Above is link to MIT paper that concludes diesel hybrid is superior to gasoline hybrid for full life-cycle carbon emissions.
May be interesting read for some here.

The emissions currently emitted by vehicles are at a level that my concern is conserving resources.
Safety, type of energy used and sustainability, cost of use, MPG, driving experience are my top criteria when deciding on a personal vehicle.

moparbad · June 2004

Can hybrid succeed without tax credits? Diesel passenger vehicles require no tax subsidy (and I do not want them to receive a tax credit). IMO it makes no sense to subsidize a persons choice of vehicle in a free market.

john1701a · June 2004

The actual DEDUCTION (there is no credit) is basically just an advertising tool, an industry-wide way to raise awareness about the new technology. But rather than actually running ads, the government lets word-of-mouth do it and gives the money directly to the consumer instead. In short, it's a less expensive way of doing promotion they'd end up doing anyway. Remember, there are other government programs that give money for being clean. Just research the problem Atlanta is currently dealing with. They are at risk to lose their highway funding due to their pollution being at the danger level. Also, did you know small business owners can get a CREDIT for half the cost of a Hummer?

Anywho, since the deduction only works out to about $350 for the average person, it's hardly a big deal. And it expires in 2 years anyway, with each year providing less and less.

JOHN

john1701a · June 2004

I strongly suggest you read the "challenges" section on page 126.

It supports exactly what I've been saying all along about diesel not being able to easily compete with gas when it comes to the reduction of SMOG related emissions.

JOHN

sebring95 · June 2004

The system includes a heater to maintain liquid state of the fuel."

Ouch, that's gonna use a lot of energy just to maintain the fuel at a usable state.

Not really, the heater is that big lug of steel under the hood that gets hot anyway. The only inefficiency of a veggies system is simply having to start the engine on dino diesel until the engine temps are high enough to warm the veggie oil. Not a good system for someone driving very little, or just around town. Best is for someone like myself running 30k-40k miles per year out on the highways. I could pay for the system in one year if I wasn't too lazy.

djasonw · June 2004

During a gas shortage my friend who had a diesel vehicle was told by someone from an oil company to use heating oil in his car as an alternative. My friend said his car ran flawlessly. If this is true, why aren't people using less expensive heating oil in their diesels? I actually have an oil burner in my home (most of Long Island does) and I pay $1.29/gallon. I have to say, that's quite tempting.

seajayacas · June 2004

Heating oil runs fine in many diesel applications

john1701a · June 2004

> why aren't people using less expensive heating oil in their diesels?

Because it is illegal.

In fact, it is illegal to use veggie oil in some places too.

The reason is because it is even dirtier than diesel.

JOHN

midnightcowboy · June 2004

>The primary goal of Prius is to reduce emissions,
>not increase efficiency (that's secondary).

John you have stated this several times. I am not sure if this is just your opinion or if there is a Toyota document that backs it up.
However, I do not believe it is exactly as you state or the Prius would be totally electric EV which would have absolutely no emissions.

I would be interested to learn what Toyota internally says about Prius emissions.

Thanks,
MidCow.

davidnj1 · June 2004

First, let me state that I had the bank check for $27k in hand to pickup a Prius a couple of months ago before we ordered a CDI this weekend.

The Prius is amazing technology. Direct-injection, spark ignition engine (would be 30-35mpg by itself in a 110hp, 2900# car). The add in the electric motor, batteries, and controllers and you have a nice package.

However, for me, some of the other things let me down. One is the Bluetooth. A car-phone integration that you can't dial while driving is useless. This a Toyota problem, not just a Prius, and something my wife reminds me of everytime I say: "We could have gotten the LS430."

That problem also effects the navigation, however to a lesser extent. Other issues are slightly short seat cushions, no valet-lockable storage, and some missing features (e.g., expected at that price point: heated/power seats).

A tire change would have handled some of the noise and ride issues (the car comes with really low end tires).

We tested the Passat TDI. We didn't think it offered any significant advantages over the Prius, and its diesel was rather noisy.

The E320 CDI is higher in NOx, but it is low in COx. And in real world driving economy is 30-35mpg vs 19-22 mpg for the gas version and 40-45mpg for a Prius. And it is much faster. An MB CDI with a smaller engine (e.g. E220CDI or E270CDI) would be closer to the Prius in both acceleration and fuel mileage.

Moreover, the CDI basically gives you an uncompromised MB E-class. Performance, noise, ride, features are all there. The cost is nearly exactly double the Prius. However at 80,000 miles or so, when the Prius battery warranty expires, some of the price disadvantage will go away.

The diesels big advantage is in part throttle operation. On the highway, where only 50-70hp is needed to maintain 75mph. The hybrid's advantage is in start/stop traffic, where it maximizes its edge from regenerative braking, electric motor torque from rest, and ability to turn off the ICE engine when at rest.

Yes, I believe in 10 years the majority of new vehicles will be diesel hybrids. The NOx problem will be solved by exhaust cleansing and more precisely controlled and efficient combustion.

I expect an E-class diesel/hybrid of 2015 to produce less emissions than someone walking while delivering 40-50mpg in the real world. For now, we have voted.

David

Note: There actually are compromises in getting an MB CDI: some options are not available on the CDI in the US that are available on the other E-classes here and on CDIs in other countries.

john1701a · June 2004

> if there is a Toyota document that backs it up.

There is lots of documention and it has been pointed out on several occasions already.

The fact that the engine runs for the sake of heating up the CAT, even though the car isn't even moving is all the proof you really need.

JOHN

john1701a · June 2004

> I do not believe it is exactly as you state or the Prius would be totally electric EV which would have absolutely no emissions.

"totally electric" does not mean "no emissions".

The electricity has to come from somewhere. And in many areas throughout the United States, it is coal... which actually causes more overall pollution than just using gas.

JOHN

john1701a · June 2004

> However at 80,000 miles or so, when the Prius battery warranty expires, some of the price disadvantage will go away.

Wrong. It is 100,000 miles in all states but NY & CA, where they get a 150,000 mile warranty.

> The hybrid's advantage is in start/stop traffic

Owners report 48 to 52 MPG on the highway. If you don't think that's an advantage, you've probably been standing too close to a diesel exhaust pipe.

JOHN

sebring95 · June 2004

why aren't people using less expensive heating oil in their diesels?

Because it is illegal.

In fact, it is illegal to use veggie oil in some places too.

The reason is because it is even dirtier than diesel.

JOHN

Wrong, in some places it's actually cleaner fuel depending upon who you buy your fuel oil from. Many BP/Amoco distibutors sell their premium diesel for heating oil, and it's 30ppm sulphur which is about 10% of standard on-road #2.

The real reason fuel oil is illegal is because it doesn't have any fuel tax included in the price. I've not seen any legislation yet that actually makes veggie oil or home-made biodiesel illegal per say. Fuel oil is specifically dyed to indicate that fuel tax has not been paid and it's intended for off-road use only.

ratbert1 · June 2004

"So someone wants to think about nuke power in Cars? Small reactors have already been explored for their usefullness. What do you think has happened to all of the non spent fuel that was originally the explosive elements of the former Soviet threat? There must be tons of the stuff. Do you think that it is just sitting in the former USSR and not being re-processed into a useable fuel?

Who needs money the most? Perhaps the Russians or their cohorts in other parts of the former foe? Start thinking. Where is the money going to show up at? If there is money to be made from the old materials, then it is most likely going to happen somewhere and probably in a area where life is very cheap. In todays world, it would be expensive and dangerous to try such a project in our area of the woods... Oh well, food for thought???

I guess the potential for nuke fuel for use in cars is really out there and it is just a matter of time before it becomes available..."

I'm not sure what you're trying to say here. We can not even get a badly needed power plant built because of public opposition. A plant that is operated by NRC trained people. A plant that is regulated by the NRC. How on earth could we build a nuclear powered car?! I don't mean from an engineering perspective (I'm a nuclear engineer). I mean from the perspective of mass producing one in the real world. Would EVERY worker on the production line get certified to handle nuclear materials? They'd have to. Would every person who buys one have to be certified as an operator and then re-certified yearly? They'd have to. Every fire department and medical team would also have to be certified. What about repair shops? Where does the car go when it gets totalled? What about when it dies for any reason? Do the junkyards now have to get certified, too? Then they need security. And the list goes on and on.

Russia's unused weapons-grade material? Russia has a deal with the US (and others) where they are taking their excess highly enriched fuel and blending it down to commercial power fuel, then we are buying it from them to run in our plants. This is being done at facilities like Tomsk-7 (now known as Seversk). Make sure you know what you're talking about before you talk.

The thought of a nuclear powered car is simply rediculous.

djasonw · June 2004

Truth be told, I really don't care if home heating oil is technically illegal. I can assure you that all the oil delivery trucks that deliver fuel on Long Island are using heating oil as their source of fuel. The way the government wastes our money, I don't mind avoiding fuel tax for the sake of saving 50 cents per gallon. However, there is no way I am giving up my Prius and buying a diesel. I also have to think of the planet in my quest to save a few bucks. Once diesel is cleaner, I'll revisit this possibility.

john1701a · June 2004

> The real reason fuel oil is illegal is because it doesn't have any fuel tax included in the price.

Yup, I'll buy that. It wouldn't be the first time something was "regulated by money".

JOHN

usbseawolf2000 · June 2004

"The Prius is amazing technology. Direct-injection, spark ignition engine "

Prius' ICE is direct ignition, not direct injection. I sure hope the next gen to use direct injection.

"The diesels big advantage is in part throttle operation. On the highway, where only 50-70hp is needed to maintain 75mph. "

The classic Prius' Atkinson cycle engine can make as low as 7hp without affecting it's efficiency. HSD also has big advantage in part throttle operation as diesel compared to Otto cycle gas engines.

Dennis

gagrice · June 2004

Think I'll jump in here. I just looked at the Toyota Prius website. It looks like the warranty is now the average 3 year 36,000 miles. What happened to the bumper to bumper 8 year 100,000 mile warranty? Now it takes a lawyer to figure out what they cover and for how long. As far as fuel economy I have two friends that bought a Prius. They are getting in the 41 mpg range with freeway driving. The special order tires are also an issue. So it is not all rosy with the hybrid world. PS, I would take the MB E320 CDI over anything Toyota has ever built. Not in the same league, even the Lexus and I own one..

djasonw · June 2004

Having owned 3 different Mercedes in the past 3 years I tend to disagree. They are extremely temperamental cars. Their quality is NOTHING like they used to be in the mid 80's. Just close the door on a new Mercedes vs one from the 80's and you'll see what I mean. Consumer Reports and JD Power report much higher incidents of repair too. Give me a Toyota/Lexus ANY day of the week of the current Benzes.

john1701a · June 2004

> What happened to the bumper to bumper 8 year 100,000 mile warranty?

There never was one. That duration & distance is for the hybrid (electrical) components only.

> They are getting in the 41 mpg range with freeway driving.

That's possible if they allow their tires to run soft, overfill the oil, drive fast, drive aggressively, have the Heater or A/C on full, etc. But most owners don't, so they get upper 40's.

> The special order tires are also an issue.

The 2004 doesn't have special tires. They are just run-of-the-mill Goodyears. The 2001-2003 used to, but owners stopped using them a long time ago and just switched to run-of-the-mill tires. (In fact, I did with my 2001 and didn't take a MPG hit at all!)

JOHN

ratbert1 · June 2004

"That's possible if they allow their tires to run soft, overfill the oil, drive fast, drive aggressively, have the Heater or A/C on full, etc."

yikes. Granted I don't run my tires soft or overfill the oil, but I like to enjoy driving (read: fun and aggressive when there's no traffic, which is often) and where I live in NY there are many days when I blast either the AC or the heat. But that sounds like boxing yourself in. I could do that with my Subaru and get another 3+ mpg out of it I'm sure. Let's see, don't press the gas pedal more than 1/4 down, don't take the rpm's over 2500, don't turn on the AC or stereo, don't drive over 50 mph, leave the windows up for better aerodynamics, remove the rear seats when not in use, etc.

The more I read about hybrid, the less I like it. I don't necessarily care about squeaking that extra mpg out of it, I care about getting better overall mpg with my driving style and automotive needs. Hybrid doesn't seem to fit that.

john1701a · June 2004

> I don't necessarily care about squeaking that extra mpg out of it

Most people don't. So they are quite content with getting upper 40's for MPG, rather than 54 MPG like I'm getting.

Instead of blasting the Heater or A/C, just use a lower setting. Comfortable is quite realistic without using the maximum setting.

Instead of driving +75 MPH, drive 70 MPH. Or even better, take a slower highway, since they usually have less traffic anyway.

Instead of weaving through traffic and always being the first off the mark, just drive along with the rest of the crowd.

And sorry, no offense, I don't believe anyone that claims they properly maintain their tires unless they actually mention detail. I have even caught other hybrids off guard, by asking to verify by actually checking. Tires naturally leak, that's a fact. Plus, temperature changes cause the PSI to drop. That means unless you are either running above standard pressure or checking them twice a month, you are not maintaining them properly.

The same goes for the oil level. Change places squirt oil straight from a large barrel into your engine. There is literally no way to measure without stopping and carefully checking the dipstick. Most don't bother. 1/2 quart too much is very easy to squirt in. And that just kills MPG.

Switching to synthetic oil is a very simple way of increasing MPG too.

And of course, the least obvious but most beneficial tip is to stop taking short trips. Just a few minutes behind the wheel with a cold engine makes MPG plummet. (It's hard on the exhaust system too, no time to purge moisture build up.) Instead, just combine errand running into a series of short trips. Many people prefer to get that kind of chore over with anyway, so that tip is a welcome one.

The point is that these tips are common-sense and apply to any type of vehicle. If you do the same in a traditional vehicle, lower than estimated MPG will be the result with it too. This is not totally unique to hybrids, as some imply. It's just that you have a computer informing you of your behavior in a hybrid. In a traditional vehicle, you have no easy way of knowing.

JOHN

ratbert1 · June 2004

It's interesting how you make assumptions about me that allow you to take an argumentative position right from the get-go.

"Instead of blasting the Heater or A/C, just use a lower setting. Comfortable is quite realistic without using the maximum setting."

When I get into a car that's sweltering hot from being in the sun, I BLAST the AC. It's hot and I'm uncomfortable.

"Instead of driving +75 MPH, drive 70 MPH. Or even better, take a slower highway, since they usually have less traffic anyway."

Did I say I drive over 75mph? I don't. Less traffic than none? That's hard. Remember I said "when there's no traffic".

Did I say anything about weaving through traffic? In fact I specifically said "when there's no traffic". DON'T TWIST MY WORDS!

First off the mark? What mark? You know my commute? Once again, there's little or no traffic on my commute. And besides, have you driven a 4-cyl Subaru Outback? Not exactly the best acceleration.

You don't believe that I maintain my tires? I don't care.

As for oil changes, I've never had anyone else do them except myself. ever.

"And of course, the least obvious but most beneficial tip is to stop taking short trips."

That's a good one!

Just try and convince a huge corporation to move their industrial complex out to my house in the boondocks on a lake. What do YOU consider a "short trip"? It takes me 20 minutes each way just to buy a gallon of milk. I'm not complaining (before you twist THAT around), just pointing out that nothing is a short trip for me. I love where I live.

All of these questions are rhetorical. Please do not answer. I have defended myself against your attack and close by saying that I will not waste any more of my time on this kind of stuff.

john1701a · June 2004

Hmm? There is nothing personal mentioned.

It is just a generic set of comments, the same tips repeated on many other threads, to many other readers, many other times.

Many discussions have turned non-constructive due to not having a basis to discuss from. In fact, just last week exactly that happened on the "up to the chore" thread. So this time, those facts were provided.

Seriously, nothing personal was intended. You obviously didn't read it that way though. Sorry.

JOHN

davidnj1 · June 2004

I thought the Prius had a state of the art motor (like the new Audi, MB, and BMW engines). It has a regular technology 4-banger more or less. The Atkinson cycle is 100 years old, is not any more sophisticated than holding the intake valve open longer for lower dynamic compression while maintaining the greater chamber expansion of a high compression engine. Same as the Mazda Millenium S my wife bought in '95.

I had (mistakenly) thought that Toyota was using a high compression direct injection stratified charge engine. Oh, well. If Toyota puts in a modern engine they might get a 5-10 mpg increase, real world and probably highway. Then of course we would have to complain about the low quality US gas which holds back the BMW, Audi, and MB engines and would do the same to the Toyota!

Using the fuel economy tricks discussed elsewhere (no power accessories, light foot, etc.) drivers have gotten the E320 CDI into the high 40s mpg. I imagine a VW would break into the high 50s.

There is no doubt that the Prius is more efficient than the MB CDI, it weighs 900# less, has less frontal area, lower drag coefficient, and runs on lower rolling resistance rubber.

It appears that the MBs oil burner is more efficient than the Prius's gas engine, and the MBs Sensotronic brakes will have less friction (electrically retracts the pads from the rotors.)

Definition of the Atkinson Cycle follows:

The Atkinson cycle may also refer to a four stroke engine in which the intake valve is held open longer than normal to allow a reverse flow into the intake manifold. This reduces the effective compression ratio and when combined with an increased stroke and/or reduced combustion chamber volume allows the expansion ratio to exceed the compression ratio while retaining a normal compression pressure. This is desirable for good fuel economy because the compression ratio in a spark ignition engine is limited by the octane rating of the fuel used, while a high expansion ratio delivers a longer power stroke and reduces the heat wasted in the exhaust. This makes for a more efficient engine. Four stroke engines of this type with forced induction (supercharging) are known as Miller cycle engines.

gagrice · June 2004

It seems that hybrid owners are over sensitive about the vehicle they drive. We all would like better fuel economy whether we are driving a Mini-Cooper or a Suburban. The discussion is Hybrid vs Diesel. When and if the car manufacturers get as many choices of hybrid vehicles as diesel, maybe we can all get better mileage. The only reason I would buy a small car like the hybrid Honda or Prius is for the short trips to the store and movies. Now you tell us that they are not very efficient unless you drive them over a certain distance. Sounds like Toyota and Honda need to go back to the drawing board.
P.S.
The first Prius in San Diego was 8 year 100,000 mile B to B warranty. I almost bought it. Unless the Toyota dealer was lying to me...

gagrice · June 2004

Where did you learn all that about engines? I like it...We need to keep the hybrid crowd honest and feet planted on the ground. What do you know about the new diesel engines in the Honda and the MB E320 CDI? They have me interested.

Hybrid vs Diesel

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