Value of Engine Efficiency??

[SBBlue]

Here's a somewhat general question I would like to toss out to the group.

What is the value of engine efficiency? Now I'm not talking about vague concepts here, but something a little more concrete.

If there was something that could be bolted on an existing engine that would increase fuel efficiency by, say, 30% -- how much would that be worth?

For convenience sake, let's restrict the discussion to new engines, but allow them to be either gas or diesel engines. Would consumers pay 30% more for an engine that was 30% more efficient? How about 30% more for an engine that was 10% more efficient? Or 50% more for an engine that was 50% more efficient?

And just for argument sake, let's say the engine modification doesn't effect the engine in any way other than the efficiency -- i.e., it doesn't affect the engine's power output, power density, durability, ease of operation, service requirements, volume or weight characteristics. To keep a little bit of realism, let's say the cost of manufacturing the modification also increases 30%. In other words, every thing is the same, except the engine is now 30% more efficient. How much is that worth?

For extra credit -- let's suppose that a manufacturer was going to have to drop a certain vehicle due to fuel efficiency requirements. How much would they pay (in percentage of current cost) to have a modification that increased efficiency 10%, 20%, 30%, 40%, 50%?

My feeling, based upon absolutely no evidence whatsoever, is that the increase in value of the engine would about be equal to the increase in efficiency. However. . . .I also suspect that people would be willing to pay 100% more for an engine that was 50% more efficiency.

I'm anxious to hear the collective wisdom here!!!

 

[al1]

Wow! I think everyone would like to know the answer, as I believe it to be more of marketing question --- with the fickle market place and the challenge of predicting just what people will buy being an ongoing task of looking into the preverbal “crystal ball”. Lets face it, value is in the eyes of the beholder, complicated by perception and/or what is the latest trend of the month. The obvious example would be the cost justification of miles per gal and the return on investment. Yet there are the so-called do gooder's and/or tree huggers that will think they are doing something for the betterment of the world that bought into the electric car thing from GM. It obviously went nowhere and cost them more than if they kept driving their old cars, but they though it was the right thing to do. Until recently, if you really run the numbers, it’s almost impossible to justify getting a new car for improved miles per gallon alone. However, as the fuel cost increase this will be easier to justify especially if you have to get another car for whatever reason anyway. Another big thing is fashion and/or image as it’s an area that is very rough to guesstimate as again it’s in the eyes of the beholder. I personally think that the “bang for the buck” is still the major driver and on average, more people are nether neither dumb nor impractical but will go with the best alternative value. Note, alternative is the key word as competition is also a part of the equation and it too is an ongoing dynamic thing as well i.e. hydrogen and/or fuel cells being some of them.
Al1

 

[ivymike]

I think the question has been improperly restricted. Improved efficiency usually translates to greater power output from a given package (incl cooling system) size, which means your pickup truck can get on the highway a fraction of a second faster. High engine power is a status symbol worth lots of money, as engine sizing trends would seem to indicate. Fuel economony be damned, we consumers want to be able to turn fuel into "go" as quickly as possible. With highways as congested as they are these days, the only way to get reasonable speed out of your car is to accelerate as rapidly as possible when gaps open in traffic, then to brake as rapidly as possible to avoid hitting the guy in front of you. As fuel prices get higher, we'll look for politicians and corporations to blame, while demanding ever-greater acceleration and size from our vehicles. Speaking of which, why hasn't anyone come out with an SUV with a cargo bed on top of the roof? That way you could put 4 rows of empty seats inside, and the groceries on top! There'd be nothing taller on the road!

 

[GregLocock]

The true answer is: not much.

Here's how I'd look at it.

A Prius achieves a real world improvement in fuel consumption of X%. This is pretty much the equivalent of an X% improvement in BSFC, or efficiency.

The price premium of a Prius over the equivalent car is $Y.

Now, the Prius is selling very well, partly because of the 'cool' factor (well, that or the 'geek' factor), so that incremental price premium represents what that particular market will pay for increased efficiency, plus a bit for cool/geek. Your mission is to identify the competitor car, X and Y, and try and figure out the image effect.

Fleet managers take a very hard-ass view on this. Just work out the decreased cost of ownesrhip and offset it by the increased cost of finance.

For instance our V8 and turbo I6 sell very nicely thank you, for a premium, despite being markedly less efficient than the base car. For that matter I know which I'd rather have.



Cheers

Greg Locock

 

[crysta1c1ear]

This isn't the answer to the question you asked, but its related. I read that manufacturers are prepared to tolerate a $50 increase in the price of a car if it brings them a 1% fuel saving. Why? Well, in Europe at least, the ACEA manufacturers have promised to be 25% more fuel efficient by 2008 or suffer the consequences. The consequences would likely be to have the fuel economy values pushed on them in the form of legislation.

Publicly, the big car makers will produce image vehicles and make statements about fuel cell vehicles and hydrogen, but they will attack fuel economy when hiding behind anonymity via the auto alliance.

http://www.autoalliance.org/index.php?flash=no

Resistance can only limit the severity of the fuel economy legislation. The Chinese governement is in the process of introducing stricter fuel economy legislation than the US, and at the same time investing in (exclusive?) intellectual property licences for modern fuel saving technology for some of its state owned manufacturers, so that they will be competetive when they start to use their world trade organisation status to become global players.

So fuel economy can become a virtual trade barrier hidden behind the disguise of more slowly double glazing the greenhouse we have put in place. If the fuel economy trade barrier was the only factor in the economics of car production, and of course it isn't by a long way, the winners would be the nations with the tightest fuel economy legislation.

So, $50 per vehicle per 1% fuel saving is what I have read the manufacturers are prepared to pay. OEMs need to pay, even if they cannot recover the costs. That's from memory, so other figures are welcome.

 

[SBBlue]

As I read these responses one thought occurs. . .

It is sort of perverse, but it turns out the advantage of the hybrid engines is not so much that they increase gas mileage, but that they increase acceleration, and that allows smaller engines to be used in cars.

These cars use miniscule size engines, which are capable of propelling a small car in cruise at 60 mph, but by themselves will not produce much acceleration. The smaller the engine, the better the engine efficiency, because the smaller engine operates at a higher rpm to produce the same amount of power as a larger engine. But the smaller engine will not have as much power reserve for things like acceleration and climbing hills.

Enter the hybrid; you can increase power during acceleration by using an electric motor powered by a battery which is charged during cruise.

In cars with the same engine and at cruise, the hybrid should have worse fuel mileage than the standard car.

 

[GregLocock]

Sure, but from a system perspective why would you do that?

Crystalclear, so if I pay $5000 extra can I have a car that uses 100% less fuel?

haha. Actually 0.99^100 is 0.37, so it would use 63% less fuel.

Actually that figure is in the right ballpark, from memory.

Cheers

Greg Locock

 

[rpmag]

Well I am in new car market in this year. Would purchase Ford's (Australia) excellent territory, however economy is an issue. IF it ran on LPG it would make a difference as fuel is 40c/lt vs current $1.05/lt for ULP. I would also purchase it immediately if it had 30% better economy!

 

[GregLocock]

How much extra would you pay for LPG?

Cheers

Greg Locock

 

[crysta1c1ear]

I just did some calculations.

I don't have a figure for the energy density of LPG, but I have 43MJ/kg for petrol and a quick Google gave me this phrase The energy density of LPG is typically a third less than for petrol (23.6 MJ/litre as compared 32.3 MJ/litre).

I have density figures, 0.740 g/cm³ for petrol and 0.520
for LPG. So LPG gives about the same energy per kilogram and less per litre due to its lower density.

Combining energy densities, densities and prices I get this

Petrol
43KJ/kg * 0.74g/cm³ / $1.05 per litre = 8.42 KWh/$
or 11.88 cents per kilowatthour

LPG
'Estimate 44.88KJ/kg' * 0.520g/cm³ / $0.40 per litre = 16.21 KWh
or 6.17 cents per kilowatthour
(I just used Octane as an approximation for LPG energy density so figures won't be very accurate.)

==

So the equivalent price for LPG is about 77 cents. More than that, and the petrol is cheaper, since you get more kilos per litre.

========

Greg,
100% less fuel is hard, but the autocompanies use fuel economy in miles per gallon, as that gives bigger numbers. To start off with, 99% petrol consumption is 101% MPG so 1% is 1%.

But 50% less petrol consumption is 100% more MPG. So the auto companies can impress us with slightly bigger figures if they define fuel economy in MPG. If you want impressive numbers, turn your fractions over!

 

[crysta1c1ear]

In cars with the same engine and at cruise, the hybrid should have worse fuel mileage than the standard car.

That's open to debate. By cruise, I take it to mean a point in time when the batteries have been charged. Wind and rolling friction are key factors and the weight of the batteries and other hybrid equipment doesn't really come in to it. Volkswagen have argued in the past against hybrids on the grounds of the cost penalty of lugging the hybrid equipment up hills and accelerating it - but they seem to be coming round to the hybrid idea too.

Hybid doesn't imply CVT. The two ideas have been associated since that is what is commercially available at present. So it boils down to a question of whether a large motor-generator is more of a drain on the engine than a smaller alternator. Some of the motors mass can be performing flywhel type functionality so the extra bulk is all bad. The higher electric capabilities of a hybrid vehicle mean that some mechanically (permanently) driven devices can be replaced by electrically (on-demand) driven devices. The alternator is often belt driven whereas Honda have integrated motor assist designs where the motor is (via a planetary gearset) on the crankshaft on the other side of the engine to the transmission.

I know what you are saying, and in general I agree, but I don't think that it is clear cut.

Early mild hybrids are likely to be implemented by belt alternator starters, but as friction launch clutch automatic transmissions are more widely implemented, an easy space to grab to put an reasonable sized electric motor (without redesigning vehicles, engines or gearboxes) is where the torque convertor currently sits. Is an inline electric motor going to be worse than an alternator on the pulley?

 

[crysta1c1ear]

Meant to write ".... so the extra bulk isn't all bad ...."

I know "highway" and cruising are not quite the same. This is more to illustrate a point. I know it proves nothing. Increased MPG is partly due to electric power steering, etc, and I know that can be provided without a car being a hybrid. I'd better not say more or you'll think I'm justifying better cruising with a hybrid based on auxiliary devices rather than on mechanical efficiency of starting and generating equipment and how that connects to the engine.

====================
References

http://world.honda.com/news/2004/4040917.html

2005 Honda Accord V6 hybrid, (240 HP + 15HP motor), 37 highway EPA fuel economy

In addition, the Accord Hybrid delivers 255 horsepower (versus 240hp for the Accord V-6 Sedan) with an exceptionally broad and flat torque curve for outstanding power and driving performance.

http://autos.msn.com/research/vip/spec_engines.aspx?modelid=11412&trimid=-1&src=VIP&tab=2&sub=1

Click on Engines and performance
30 miles per gallon highway.

 

[SBBlue]

Do these cars have the same engine?

From the website you mentioned;

"The all-new Accord Hybrid utilizes the third-generation of Honda’s advanced Integrated Motor Assist (IMA) full hybrid system in combination with new Variable Cylinder Management (VCM) cylinder deactivation technology to deliver the world’s best V-6 fuel efficiency – on par with a 4-cylinder, compact class Civic."

I didn't see any reference in my very cursory glance of the websites to indicate that the non-Hybrid engine has the Variable Cylinder Management.

I would suspect that the cylinder deactivation technology is responsible for the increase in gas mileage at cruise.

 

[crysta1c1ear]

FAO SBBlue
I'll check it out later. Obviously 30 to 37 is a big difference and its going to be due to factors that have little to do with the hybrid setup since the motors have nothing to do when cruising.

It could even be that the high milage figure is due to partial battery depletion during testing. I think the EPA plans to change their tests to take hybrids better into account. I suspect that rules allow cars to have a fully charged battery when testing starts. The problem with testing hybrids then is that they may prefer to run with a half charged battery - that way there is space in the battery to store results of regenerative braking. So during the tests, the hybrid's logic could decide the battery was overcharged and use the motor. This is obviously going to give better milage than just using the engine, even if the car is just cruising.

==

All I was trying to say is that hybrids maybe don't need to have worse fuel efficiency, other factors being equal. I think it will be very difficult to find a good example supporting my case. That was the best I could find, and I admit it wasn't too good.

Maybe I'll have to wait for variable cylinder management to filter down to the non-hybrid to have a fairer comparison.
I'll check the VCM status tomorrow if I can, but I already guess you're right.
Goodnight!

 

[MaxRaceSoftware]

What about the "Cost Efficiency"

i just had to replace the Alternator on my Daughter's
GEO Prism 4 cyl ..$300+ rebuilt $600+ new lifetime warranties both cases

if i drive a 10 mpg Suburban 15,000 miles @ $2 per gallon = $3000

if i drive a 30 mpg GeoPrism 4 cyl 15,000 miles @ 2 = $1000

a difference of $2000 in this example

but if i have to fix any part on the GEO , its 2 to 3 times
the cost of the Chevy V8 Suburban..there goes some of the gas mileage gains

looking at alternate fuel vehicles, or Hybrids, or Hydrogen Cars ,...whats going to be the cost to change or replace any Part ?? is the price difference going to wipe out any gains you made in gas mileage ?




Larry Meaux (maxracesoftware@yahoo.com)
Meaux Racing Heads - MaxRace Software
ET_Analyst for DragRacers
Support Israel - Genesis 12:3

http://www.maxracesoftware.com/

 

[notnats]

Larry,

Motoring now is incredibly cheap compared to say 40 years ago when cars needed service every 1000 miles, rings and bearings needed replacement at 50,000 miles and valve grinding was done every 20-30,000 miles. My dad had a '52 Plymouth that needed a rebore at 45,000 miles despite being well maintained and carefully driven.

It might be that the cost of maintaining a more complex system might be the penalty we have to pay for driving in the future just as other maintenance costs were accepted in the past.

Jeff

 

[crysta1c1ear]

The cost differential won't be so much when the era of cheap fuel comes to an end.

At the moment, there is something like 0.75 cars per person in the US and 0.01 cars per person in China. The Chinese will buy cars and then want to fuel them. China will be the world's biggest automarket.

When that happens, one might find it easier to get a new alternator than to get one thousand five hundred gallons for a Chevy V8.

 

[rpmag]

Greg,
I would not flinch at a $1500 price increase, especially if there was a dual fuel option, a small 20lt petrol tank as LPG is not always available everywhere.
I have dual fuel on my current car (Ford Falcon) and have run the numbers over 12 months. As this is based on dollars spent and odometer it is reasonable to expect that this is at best a very rough guide, but I have found an approximate 30% saving in dollar terms running LPG. This did not take into account the installation cost as that was done by the previous owner.

 

[patprimmer]

I would actually sooner have single fuel with the engine optimised to LPG so as to get the best result, but then it would require a substantial increase in tank size, twin tanks being the optimum, so you only carry the extra fuel load when going to areas where supply might be an issue.

My current SUV uses about A$5280.00 per year in petrol at A$1.10 per litre, 16 litres per 100 kilometres and 30,000 kilometres per year.

On a good LPG only system, it would use 18 litres per hundred kilometres at about A$0.50 per litre or A$2700.00 per year. I would certainly pay A$3000.00 extra for the LPG version.

Regards
pat pprimmer@acay.com.au
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[franzh]

I think Greglocock hit the nail on the head.

The actual efficiency is how much does the vehicle cost to operate over a given distance. If milk (substitute your metaphor of choice) were used as a fuel, and the price of milk was 1/4th the cost of gasoline, then the cost per given distance would be 1/4th of gasoline.

Hybrids have a "cool" factor, but they will never win any performance contests. Their gasoline engines are marginally more efficient than their dedicated counterparts, but they operate in a more efficient mode, plus, the vehicle package makes more use of waste energy lost during braking etc. The 2004 Prius I had the opportunity to drive recently is nice enough and would certainly be high on my want list, but 90% of my driving is highway driving, where the hybrid is least efficient. The Honda Civic (non-hybrid) I test drove actually outperformed the Prius and got equal mileage.

My comment is that it is not just the engine, but the whole automobile package that contributes to efficiency. In the US, its called "where the rubber meets the road".

Franz

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