Value of Engine Efficiency??
Value of Engine Efficiency??
(OP)
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!!!
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!!!





RE: Value of Engine Efficiency??
Al1
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
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
RE: Value of Engine Efficiency??
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.
RE: Value of Engine Efficiency??
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.
RE: Value of Engine Efficiency??
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
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
Cheers
Greg Locock
RE: Value of Engine Efficiency??
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!
RE: Value of Engine Efficiency??
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?
RE: Value of Engine Efficiency??
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.asp...
Click on Engines and performance
30 miles per gallon highway.
RE: Value of Engine Efficiency??
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.
RE: Value of Engine Efficiency??
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!
RE: Value of Engine 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/
RE: Value of Engine Efficiency??
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
RE: Value of Engine Efficiency??
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.
RE: Value of Engine Efficiency??
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.
RE: Value of Engine Efficiency??
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
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Value of Engine Efficiency??
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
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Value of Engine Efficiency??
rpmag will pay 1500 for a 30% reduction in fuel costs, Pat will pay 3000 for a 49% reduction.
Wow. That is a tough market, but pretty much in line with the $50 per 1% improvement we came up with before.
It still staggers me that by that logic neither Pat nor rpmag would pay $7000 extra for a car that uses no fuel!
Cheers
Greg Locock
RE: Value of Engine Efficiency??
If the equation was no 'fuel' but say much greater servicing costs etc...well then the total overall package is what I would consider.
RE: Value of Engine Efficiency??
My opinion is based on time to repay investment rather than actual %age decrease in operating costs.
I would pay nothing if I only did 1000 ks per year, but I would pay a lot if I did 100,000 ks per year.
I never considered the no fuel deal, as I once raced a sailing boat, and I know just how much it costs to catch the "free" wind and convert it into motion, or at least how much it costs when you try to convert it into more motion than anyone else in the fleet. Just ask the guys who race for the America's Cup.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Value of Engine Efficiency??
"...is that the increase in value of the engine would about be equal to the increase in efficiency."
That sounds like a pretty good estimate. The powertrain represents (along with the body) the most expensive component in the car. Once I've decided what sort of car I'm after, the first thing I look at is MPG. I expect it to handle well, be quiet and well packaged.
In fairness, I have actually been running the same Metro diesel for 11 years. I have had second (company) cars in that time, but always ended going back to the cheapest (total) way to get from A to B. You expect depreciation, and I run cars into the ground anyway.
For this market, you are better aiming the product at someone who only grudgingly replaces there favourite old hack. At 60mpg, I know my old (but modified/upgraded) machine doesn't compete against the latest generation of tier4 compliant compact cars (eg VW lupo). When my old machine does finally die (and at only 160'000 miles or ~4000 hours that won't be soon), I will do what I always do - look at MPG then go for a test drive...
Mart
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
http://www.tc.gc.ca/programs/Environment/climatech...
RE: Value of Engine Efficiency??
A new vehicle that is more fuel efficient might actually cost more over the first few years, than an older car that is less fuel efficient. That is if total running costs are the only criteria. A new car would need to be pretty good to end up in front.
In the end it probably depends on how you see your car and yourself. SUVs and sporty cars are bought by younger drivers for reasons other than fuel economy. On the other hand, a more mature driver that buys a small econo box might be vitally interested in fuel mileage.
RE: Value of Engine Efficiency??
Future Potential of Hybrid and Diesel
Powertrains in the U.S. Light-Duty
Vehicle Market
August 2004
David L. Greene
Oak Ridge National Laboratory
K. G. Duleep
Energy & Environmental Analysis, Inc.
Walter McManus
J. D. Power and Associates
(Reports produced after January 1, 1996, are generally available free via the U.S. Department of
Energy (DOE) Information Bridge:
Web site: http://www.osti.gov/bridge)
... the average customer would switch to a higher efficiency engine with no performance penalty based on a 3 year payback. The range among Californian consumers fell between 2 and 10 years, I'm not too sure how they worked back to 3 years.
It also includes a price elasticity model for hybrid and diesel vehicles.
Cheers
Greg Locock
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
The reality of the situation is that in Australia and the USA fuel is cheap, even now. People who buy hybrids are not really expecting to save money, they are mostly making a statement.
So yeah, bring on the hydrogen powered Hummer2, the hybrid Escape, and the diesel Landcruiser. The bigger the car the bigger the statement.
A couple of handy rules of thumb I've just worked out - urban fuel consumption is pretty much proportional to vehicle weight, for a given engine/transmission technology, and a car with a 0-60 mph time of 9 seconds will spend 90% of its life at 25% of full power or less.
Cheers
Greg Locock
RE: Value of Engine Efficiency??
Frankly, i get quite irritated when i see folks driving SUVs (hybrid or otherwise) just to make a statement. To me the statement is "I don't care about anyone but myself, and CO2 emissions are their problem". I am not the only person in Europe who has this view...
Mart
RE: Value of Engine Efficiency??
GraviMan I would agree that for the UK raod conditions that I experienced SUV's would be contraindicated simply for parking/road width/fuel useage issues.
RE: Value of Engine Efficiency??
Not that I'm biased but at the very least they should start taxing imported SUVs and 4WDs at the same rate as imported cars .
Cheers
Greg Locock
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
Well, RPMag, my concern is really with the CO2 emissions. My point is that someone driving an SUV in the US of A, is having a direct affect on global warming, hence the gulf stream, hence the future of my country's climate. If the icebergs continue their trend southwards (according to Canadian Coast Guards) my country is in real trouble. It's very easy to drive around in a superpower, and not worry about climate change somewhere remote like Europe.
I've got nothing against large vehicles with one occupant, i just would like to see MUCH better mpg. Ideally hybrid negates the mass problem, but these vehicles have GOT to become more streamlined. 20 mpg is just a very bad joke.
Mart
RE: Value of Engine Efficiency??
Greg I agree with you.
Graviman, my own country is in a similar position re climate change, but we are perhaps straying too far from the topic?
RE: Value of Engine Efficiency??
We were doing a cost/benefit analysis of more economical engine development...
Mart
RE: Value of Engine Efficiency??
I see that the Honda hybrid keeps the valves closed in the cylinders that are not in use-- would have thought this would be a huge drag. I once lost a cam lobe on 6-cyl Triumph and removed the pushrods from that cylinder-- power seemed to drop by half. Can part of the crank be decoupled instead?
I think the hybrids should be able to use an engine designed for a very narrow rev range and so be better optimised (and more efficient.) The electric motors can do the accelerating. Maybe combine CVT with the motors to keep a smaller engine turning at a near constant efficient speed.
As vehicles become bigger (eg SUVs) the accident damage to smaller cars increases. I drive an SUV so that I am higher (better visibility), more metal around me (safer in a crash), and bigger wheels/tyres/suspension for those off-road excursions to avoid accidents (very bad drivers in crowded Asian country.) My SUV pollutes far less than the 2-stroke bikes and 3-wheelers here plus I am contributing to the national coffers more!
What would most governments do without the tax from fuel? I read a report from one EU country which was very worried about electric vehicles as a threat to their tax revenues.
cheers, derek
RE: Value of Engine Efficiency??
You use this thread, with contributions by the guys here who do some serious work on vehicle safety, and on real gains in reducing environmental impact, and you claim you drive an SUV because of it's safety and because it's environmentally friendly.
I will let those more qualified answer this one.
Be gentle guys. Remember this site has a code of conduct that does not condone treating people with disrespect, even if they show extreme ignorance. A detailed answer that meets that code is beyond me at this instant.
Regards
pat pprimmer@acay.com.au
eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.
RE: Value of Engine Efficiency??
RE: Value of Engine Efficiency??
Sorry Pat,
The SUV remarks were partly tongue in cheek. I should have put in a
Emmissions are all bad and we suffer from them more here than most of you. My intention was never to ridicule any of the experts on this list. I guess we'll see how many were offended. FWIW my SUV is a 1.8litre GDI and has very low emmissions and is remarkably frugal.
My last point about tax revenue concerns is a valid point and will need to be addressed in the switch to alternative fuels. A project by a large auto company to build electric commuter cars in Europe was getting funding from their government and when the funding was not renewed the company was told that it was due to the govt. not having a policy yet for taxing electric cars.
cheers, derek