The problem with series hybrids
 

I've herd a few things lately that need more discussion. Namely with series hybrids like the volt and aptera appearing and folks assuming that running the engine at bsfc peak regardless of other "driveline" losses is the most efficient way to move a car. I don't believe it is, given a reasonable gearbox and a good driver, and a will and acceptable conditions (a personal decision) to drive for efficiency.

The thing is that the gas engine is billed as a "range extender", and to me that means usually a hiway trip for business/pleasure. I think a gas only solution would use less gas than a hybrid for this extended range mode, where an electric vehicle can handle the local "i.e. 40 mile radius" usage where there is a higher percentage of braking.

I've never seen anyone do any efficiency analysis on a series hybrid, as far as I can tell there are many losses to consider:

engine to generator
generator to controller
controller to motor
generator to charger
charger to battery
battery to motor
transmission/wheels


whereas a small gasser can use
engine to transmission/wheels

now that is a large number of energy conversions going on for the series hybrid, it is off to a real bad start. Lets also remember that these conversions are also not all at their peak efficiency all the time, motors and generators do not have a flat rpm/current/efficiency curve, nor do batteries have a flat efficiency curve.

So what of the benefits of bsfc peak? Well lets look at an example chart for a reasonably efficient engine:
http://ecomodder.com/wiki/images/3/3...nstruction.gif

Look at the small center "target" oval, @250. You can drive this car at within ~90% of bsfc peak from 1300 rpm to 4300 rpm!!! that is a huge rpm range. And the only equipment you need is a brain and a right foot, or from 40% load to %75 load if you have the rpm dialed in (i.e. coping w/hills). Of course this is best leveraged by pulsing and gliding around bsfc, and you do have other gears to climb hills with near bsfc peak and just glide down them.

So will all those conversions of the series hybrid outperform a "john henry" driver in terms of efficiency? I doubt it will, at least not before gas becomes obsolete anyway.

I do like the parallel hybrid short term, especially if it is just a small motor & wheel you stick in the hitch receiver of your electric vehicle, that is just sized to push you down the hiway near bsfc peak (the EV takes up the slack). To me that is pretty close to perfect (and similiar things have been done), as you still only buy one car and can go anywhere with it with minimal fuss, but move your daily commute to electric operation without waiting for the holy grail of batteries.

The only thing is (and as you said, this has yet to be seen) is how much better BSFC could we get if the engine only had to be designed to run at a set rpm? Could you get it down to 200 or 150 (according to your chart)? I honestly don't know, but thats about the only place you could make up the efficiency losses from all the conversions as you stated.

dcb -

I agree with Daox. From what I have read, if you design everything in the engine for a single RPM, you can optimize the intake and the exhaust to always operate at BSFC peak. The same optimization can occur for the emissions. Is it fair to compare an ICE BSFC to a series hybrid's (theoretical?) BSFC?

In your favor, maybe I am quoting R&D and university stuff that doesn't transition well to the real world. For example, it looks like the Volt's engine does *not* follow the single RPM rule. The engine does operate at different RPMs based on what's needed. Soooooo, it's not the kind of series hybrid I was hoping it would be. Orrrrrr, maybe the engineers saw the same thing you are describing and are also trying capture ~90% of BSFC.

From my POV, the whole point of hybrid drivetrains is that they are transition technology. Without them, you don't get to see electric motors, regen-braking, plug-in charging, and battery tech advancements being tested in the real world.

I agree that a good ecomodder can beat a regular driver in a hybrid under a broad range of driving conditions. But (again) the majority of people are not willing to take on this task.

CarloSW2

To be fair I don't think an onboard genset will primarily charge the batteries. Most of the output will probably go straight to the motor and a little bit will go to the pack, which will be used for sudden/slight changes in output. Also, EV transmissions seem to be heading towards single gear reduction, so they'll be more efficient than a multispeed box, but you're pretty much right on regarding how lossy something like this is compared to a decent parallel setup ala the Prius.

That is the problem, people claiming series hybrids are better and nobody has any source or specifics or any way to make an agreeable comparison.

lowest bsfc I know of is 155g/kwh, and it is from a 43 MegaWatt 2 stroke diesel.

can we at least agree that in the case where you have to go a long flat distance at a fairly constant speed that the lone gasser could be sized/geared/tuned to outperform an equivelant series hybrid? Even without much "technique"? Let's leave plugin out of the equation or at least account for the energy coming from the battery.

Yes, I want to see more electric used, but series hybrid is the electrical equivalent of an automatic transmission, which is probably why I dislike them the most. I think it is cherished for its convenience, while paying only lip service to efficiency.

Oh, I definitely agree there. Throw enough technology (lean burn, atkinson, EGR, cylinder deactivation) into the gasser/diesel and you definitely can beat the conversion losses of a serial hybrid.

IMO all that's needed is a parallel hybrid w/ an appropriately integrated transmission to beat a series hybrid. The biggest issue IMO, also why everyone is jumping on the EV bandwagon, is that Toyota has built a huge portfolio of hybrid patents, and anyone who wants to use something remotely close to their parallel system has to license through them, and if they don't then they tend to have a subpar system in terms of vehicle efficiency, eg the smaller Honda Insight/Civic hybrids get worse mileage than the larger Prius.

i agree it's a transition technology.
i learned a ton from my driving habits when i bought a new 2004 civic hybrid. the cluster display told me so much. within a month i was consistently reaching 53mpg with hypermiling.

53 is great, but ecomodder.com has a handful of people reaching beyond that with older vehicles.
in 2004, i didn't have the time to mess with SG or aeromodding. but the civic hybrid opened my eyes and changed my opinion and habits.

btw, i learned about SG and hypermiling from here. i was hypermiling before i knew there was a word for it.

http://www.innas.com/Assets/files/Hydrid%20brochure.pdf

Here is a series hybrid that beats them all, especially if you consider the vehicle they started with.

Hydraulic accumulator-up to 99% efficient
hydraulic motors-up to 95% efficient

Engine-pump-accumulator-wheel drive

Regeneration

wheel drive-accumulator-wheel drive

The key component is the wheel drive. It needs to be 95+% efficient. Most hydraulic motors loose a lot of efficiency when they run at higher speeds. This is why the motor needs to be in the wheel itself.

My design allows infinite variations in displacement in the wheel drive itself. The linked design requires a transformer to control flow and pressure to the wheel drives. Mine requires no transformer, and replaces the friction brakes on an equal weight basis.

In doing so it eliminates all the rest of the power train components.

Power from the engine to pump--- 95% out of the pump---99% out of the accumulator---95% at the tire.

That's 89.3475% of the engine power to the wheel.

Regeneration

Wheel motor 95%---accumulator 99%----wheel motor 95%.

That's also 89.3475% regeneration efficiency

Now you can run the engine at only it's best BSFC, because you are using it to charge the accumulator in every mode of operation, except when you are climbing a sustained grade that would deplete the accumulator.

Take your conventional vehicle and throw away.

Induction system
Transmission
axles
brakes
differential
Starting system
Propeller shaft

Use that weight saved to install an accumulator that allows you one 0-70 acceleration event. The size depends on the weight of the vehicle, but in every case it would be less than what you no longer need, listed above.

The engine starts by using hydraulic pressure from the accumulator. It shuts off when the accumulator reserve is topped off. It starts up when accumulator pressure is at a predetermined minimum that is driver adjustable.

The "engine" could be any form or design that gives you hydraulic pressure.

Electric
Steam
Diesel
Gas

It doesn't matter how you get the pressure as long as you have pressure.

The amount of energy required to stop from 70-0 will run your car almost a mile at 60 MPH. That is all the reserve you need.

In the linked design over the European test cycle, the engine only ran 11.9% of the time the vehicle was moving through the cycle, and only at its vest BSFC range.

Want a big honking engine, I don't care, it would just run for a smaller percentage of the time. Smaller engine, again I don't care, it just runs a longer percentage of the time.

The EPA estimated that fuel consumption could be improved by 80% through power train improvements alone. The INNAS design gives a 100% improvement with the same engine, in the same vehicle, through the same test cycle.

Instead we hypermile cars to do exactly the same thing the INNAS design does without any more driver input than the normal person driving normally.

Make the car hypermile itself.

Every out of system improvement:
Better aero
Lower rolling resistance
Weight reduction

Makes the engine run less to go the same distance and directly improves fuel efficiency.

Pop was a computer systems analyst beginning in 1960. He always told me to blame the system not the people. We all know people will always be the weak link in efficiency. When we make cars "people proof" by making them self hypermiling, we have solved the problem.

The biggest problem I see is that when we do make cars self hypermiling, then we will have to find another obsession!!!!!!!!!!!!!!!!!!!!!!!!!!!

Two power modules, one pure electric, one pure IC. Switch them when you need to take a road trip, or travel further than your electric only range.

One car does both jobs. When battery technology gets better you use the battery nodule more and the engine module less.

regards
Mech

A serial / series hybrid is much more efficient than an ICE -- because the electric motor is so much more efficient than the ICE. It is about 85-90% vs 5-20%. And the clutch and transmission only lower the ICE's efficiency.

Any serial hybrid should be a plug-in (heck any hybrid should be!) and the other efficiencies of an electric car apply: you can get 25-45% of your energy regenerated in city driving; and somewhat less than this on highway driving. There are no idling loses. There are no warm up time (for the electric motor).

The serial hybrid motor has a fixed load, at a fixed torque. It can be much smaller because the peak torque is what the generator requires, and it only has to keep up with the average demand on the battery. And so, the engine can/should be tuned to peak efficiency at that known output.

We have several known examples of serial hybrids: diesel/electric trains are serial hybrids -- I wonder how it is they can move a ton well over 400 miles on just one gallon of diesel? The other example is the early Mini hybrid: it had four 160HP hub motors (for a staggering 640HP total!) and it only needed a 250cc ICE to charge it's batteries -- and it got ~80mpg in charging mode.

I can only imagine how much better FE it could get if it "only" had four 40HP electric hub motors -- 160HP from electric motors and four wheel drive, traction control, regenerative braking are all simple to implement -- this Mini hybrid has 'em.

IIRC the biggest issue w/ hydraulic hybrids was cost. They can improve FE in the city by ~40% or so, but I don't think that's worth a $3000-$4000 premium versus a BE system that improves city FE by ~30%.

You should check out the link, the improvement was 100%.

Mass produced accumulators would not be as expensive as the previously mentioned power train components that would no longer be necessary.

The design I propose would be no more expensive than the brake components it would replace.

In fact if you dedicate the thought process to a hydraulic hybrid, you could incorporate structural components of the unibody as accumulators. An example would be the front crossmember that supports the suspension components. A perfect place for an acumulator.

When understood properly the cost would be LESS than a conventional powertrain and the total vehicle parts count about 25% lower than conventional with a corresponding reduction in total vehicle cost.

Also life expectancy would be superior to anything made today, whether conventional, hybrid, or electric.

Per wheel unit manufacturing cost would be about $100 each. You would never have to do another brake job in 500k miles, and by then most of the rest of the car would be disintegrating.

Imagine a Pontiac solstice (hydro formed tubular frame) where the frame itself was the accumulator and low pressure storage, with suspension components doing double duty as hydraulic conduits.

Add 4 wheel drive with good traction tires. Acceleration at the limits of adhesion of all 4 wheels simultaneously.

regards
Mech

please, petrol efficiency to petrol efficiency.
 

ug, the series hybrid has BOTH an ICE and a motor AND a generator to boot.

and I can keep my stickshift within 90% of peak load, so? if we get to assume a bunch of technology updates then I get a direct drive/no extraneous meshing top gear for my hiway (range extended) vehicle.


dude, it isn't a hybrid, it IS diesel, it runs steel wheels on steel rails (low RR) and is very aerodynamic. They don't make 5 speed transmissions big enough to propel a train is why the drivetrain is like that.

Neil, c'mon now, you are venturing into overunity land here. They are playing serious word games.
"An on-board petrol engined generator offers enough electrons to run continuously at motorway speeds without depleting the battery"
"After delivering the energy to the battery system the mileage translates to around 80mpg "

I think they mean a wall-charged battery in combination with the 250, though the 80mpg part is very unclear. but with a word like "translates" sitting there, it is so not clear what they are trying to say. Remember how popular gm was when they claimed 230mpg for the volt? And everyone called BS on it?

The question here is what is the most efficient use of petrol, and I think the inefficiencies of this petrol setup are being masked by throwing in other variables like electric wall power. If you had to sit in the driveway and recharge the battery with the engine to where it was before you left, you would not see 80mpg, you would be lucky to see 30mpg. Obviously this would be stupid to do with a wall outlet there, but lets at least try to compare petrol use to petrol use?

To me it is obvious that electric has short range covered (say 40 mile radius), and that is %90 of a typical vehicles life. if you are serious about being efficient with the petrol then why not save it for a purpose built hiway device where most batteries cannot reach? In fact you probably already have a working petrol vehicle in your garage right now, and could cut down petrol use very dramatically by adding a clean and simple EV for commuting, etc.

But lets not hide inefficient petrol use behind high hp numbers, parroted misconceptions, deceitful comparisons, or other consumer tricks.

Hi,

You've got some extra steps in there; and actually there are two ways to do serial hybrids. One is like the Volt and diesel/electric trains:

engine to generator
generator to controller
controller to motor
motor to reduction gears/wheels

The Volt has a battery that it uses first, and then if it is needed it goes into serial mode, with the ICE varying in speed to generate enough to power the electric motor. I don't think this is as good in a car as it is in a train, because a car has much more varied demands; whereas a train has so much mass, it only has two power modes (accelerate and cruise) and these are in "ultra slow motion" compared to a car.

The second uses a plug-in battery to start with and then the ICE recharges it, and then the ICE shuts off. So, the list is:

engine to generator
generator to charger
charger to battery
battery to motor
motor to reduction gears/wheels

And your ICE list is too short:

engine to clutch/torque converter
clutch/ torque converter to transmission
transmission to wheels

And the length of the list doesn't matter -- it's the efficiencies/losses for each.

A plug-in serial hybrid has a battery-only range, and for this mode it is much better than the ICE: a gallon of gas = ~33kWh of electricity (IIRC) so, this means an MPGe of 100 is about the worst you can get in an electric car. From the Plug In America FAQ:

The gas version of the RAV4 is almost 5X worse FE than the RAV4 EV.

The ICE in a serial hybrid by definition is going to be at peak efficiency ALL THE TIME. Also, by definition, it will be a much smaller, lighter, engine, and it will have smaller and lighter cooling system and fuel tank than an ICE powered car. Lets use the Mini as an example: 1.6L (I think?) vs the 250cc speaks for itself. The ICE Mini can probably get 40mpg (it is EPA 24/33), so a 10 gallon tank goes 400 miles. The Mini hybrid already gets 200-250 miles on it's batteries alone, and at 80mpg in charging mode, it only needs 2.5 gallons to get to 400 miles total.

So, the Mini Cooper gets 40mpg and uses 10 gallons of gas.

The Mini serial hybrid uses the electricity in it battery (probably about like the Tesla's?) of about 42kWh (80% of the 53kWh capacity) = 1.2727 gallons = 157MPGe for the first 200 miles, and then 80mpg and 2.5 gallons of gasoline for the second 200 miles. That is 118MPGe overall.

It's not even close.

And the Mini serial hybrid has 640HP and four wheel drive...

Trains are diesel/electric, dude:

Diesel locomotive - Wikipedia, the free encyclopedia

And they AVERAGE 436 miles / gallon / ton

http://www.factcheck.org/askfactchec...ly_move_a.html

Sure, they've got ultra low rolling resistance, but I very much doubt they are very aerodynamic.

Dude, that electricity does not get to your wall % 100 efficiency, which is why it needs to leave the discussion, as we will not agree on a fair conversion factor.

so those mpge numbers are pretty much bogus as are the wishful thinking of efficiency. I don't care about wall power for this discussion, again it isn't relevant. You HAVE to compare apples to apples, i.e. petrol use to petrol use, without getting out and pushing in one case. The point is to make best use of the petrol to minimize its consumption, not hide behind manufactured complications.

and a 640hp anything is a pinky wave.

lol, that still doesn't make them hybrids, oh keeper of definitions :)

"A hybrid vehicle is a vehicle that uses two or more distinct power sources to move the vehicle"

The gasoline has to be drilled, transported, refined, transported again -- I'm not dealing with well-to-wheel efficiency. I am comparing electricity to gasoline equivalency.

Listen: a serial hybrid is an EV that has a way to charge itself as it drives. Of course that has to be included! It is part of the system and it is THE REASON you would design the car -- and you certainly can drive it on the battery alone if don't go beyond the battery's range. And even if you do leave it out, the serial hybrid still beats an ICE powered car.

There won't be a 100% improvement for a ~$3000-$4000 premium over a BE hybrid AFAIK. ;) The BE hybrids have already proven to be successful. UPS ordered 200 of 'em, so the proof is in the pudding IMO. I've been hearing about hydraulic hybrids since 2006, and UPS is supposedly testing them too, but they haven't caught on like the BEs have AFAIK. Time will tell I suppose, but if UPS ordered 200 BE hybrids after testing, but no hydraulic hybrids after testing, I have a feeling the BE hybrid is a better deal. Barring of course UPS not being done w/ the hydraulic hybrids or something else preventing them from getting good data to compare both.

The Volt is a serial hybrid that runs in virtually the same way that diesel/electric train locomotives do -- they are both serial hybrids.

Facts are facts.

This is not a correct definition for all hybrids; it might be right for parallel hybrids, but not serial hybrids which is what we are discussing.

"A hybrid uses two or more types of motors in some combination to move the vehicle" is more accurate.

A serial hybrid uses one motor (electric or hydraulic) exclusively to move the vehicle, and the other motor (ICE usually) to power the traction motor. Batteries and/or supercapacitors, or hydraulic pressure tanks are also involved; acting as buffers/storage of the power. They are part of the system.

The only reason to use a serial hybrid in a car is to start with a plug-in EV, and give it a longer range. An EV is far more efficient than an ICE, and you can have regenerative braking, and as mentioned earlier, the ICE can be made much more efficient because it does not need to put out as much peak torque and it doesn't need a broad power band, and so it can be finely tuned to one RPM.

That is simply not substantiated, not better when on the hiway, or with a good driver (especially if good with a wrench), or for a vehicle like a 1l or a 470mpg motorcycle. It is true in the general, sloppy driver sense, but I am aiming for the ideal sense here, what is the most efficient (yet practical) use of petrol, and that is for longer range travel.

Electrics can do short range, we know this, and knock %90+ of vehicle petrol use right out if everyone had one and the grid could handle it, and they reduced their existing gassers to %10 duty.

why do we need to make MORE gassers?

Hi Dave,

On the highway, you can still get regenerative braking. The electric motor is still 90+% efficient at pushing the car, while the ICE powered car is still sitting at 20-38% thermal efficiency.

How can the Mini hybrid get 80mpg and 750 mile range in charging mode vs ~40+ in the standard car?

look, electric has nothing to do with what I'm asking, it only clouds the issue into an incomprehendable mess (i.e. what about well to wheels?!? electric motors are NOT always running at 90% either, they are rpm and load sensitive too. Of course batteries and controllers are not always operating at peak either).

The main question IMHO is the efficiency of the ICE engine and transmission, and since I'm quite happy with a chain and sprocket which has been clocked at 98% efficient for my target speed, how can an ICE running a generator running a controller running a motor (running a gear reduction) possibly compete?

I personally don't use the brakes on the hiway enough to make a difference. Brakes are a waste of energy, even with regen.

I don't buy the 80mpg figure, they didn't offer any explanations of their "translation", I CAN'T make it add up because it makes zero sense to me, the way overunity does.

It bothers me every time I hear that line in the railroad ads. No, it can't. I bet a train uses many gallons of fuel just to get up to speed. If you have to move one ton of freight, use a truck. The train will be lucky if it makes it a mile on one gallon.

The railroad ads also neglect to mention the 120mi/(ton-gallon) figure for a fully loaded tractor trailer, and that if you use rail, the load will travel more miles overall, and you'll need a truck to finish the job.

Railroads save fuel, and we should use them more. But their ads paint an incomplete picture.

And a train is actually pretty aerodynamic. It's like a paceline of 100 tractor trailers drafting each other very close. Actually, it's more like a train, with a negligible frontal area, an enormous wetted area, and unfortunate gaps between each rail car.


Anyway, I can tell you my hybrid gets its best fuel economy when the electric system is inactive. Sure, while accelerating, I could use the electric motor to shift the engine to a more efficient operating regime, but I'd have to pay the battery back at an efficiency less than 100%. When, as dcb points out in the first post, 90% of peak BSFC is easily achievable, it really doesn't pay to use the electric.

Given a series hybrid with a certain size engine and electric motor in a certain chassis, you could improve its highway efficiency by making it a parallel hybrid, without exception. Instead of the Volt running its ICE to run a generator to run a motor to drive the wheels, just use the ICE to drive the wheels once battery charge runs out.

A parallel hybrid with a large electric motor could be designed to cruise on the highway near peak BSFC, using the ICE for cruising and the electric for accelerating.

I expect my next car to be a plug-in parallel hybrid with a tiny gas engine and enough electric range to handle my commute.

Valentin Technologies, Inc. - The 170MPG Car

Artemis Intelligent Power demostrates hydraulic hybrid BMW 530i w/Video — Autoblog Green

When you compare a UPS delivery vehicle to a HH version of the same vehicle and see a 30-40% improvement in efficiency, you should try very hard to understand that the standard version is already optimized for fuel efficiency.

What would a comparable TDI VW (also optimized for fuel efficiency) do if it was getting 30-40% better mileage after being converted to a HH system.

No gas electric hybrid could touch it.

Will you spend 30 k for an BEV with a 100 mile range? Every source I have read admits that BEVs will be a very small minority of the vehicles on the road for decades to come.

Every source (the optimistic ones) tells us the battery technology breakthrough is just around the corner.

The technology for 100 MPG is already here fellow ecomodders. Read the links provided.

I can only imagine the cars we would be driving today if 1% of the resources that have been spent on BEV technology over the last 3 decades had been devoted to perfecting the HH configuration.

Also remember HH is not an exclusive technology by any means. Take the Nissan Leaf, add a rear axle HH launch assist to double the regenerative efficiency and conserve the battery. Now your range is 150 miles, under the typical driving situation a short range BEV will encounter every day.

It is truly a shame that we allow govt funding to decide the development pathway for vehicles when they do not understand the most basic principles of energy supply and transportation technology.

The same applies to emissions. In both cases we have bureaucrats deciding what has to be accomplished, when they are universally ignorant of the technological possibilities. While I am not any Europhobe, at least they have the principles right, focus on CO2 and promote efficiency in vehicles, with high fuel cost and taxes as deterrents to gross over consumption.

The US must look at all options for efficiency and energy independence. Until we do we are grossly over polluting and bleeding our national net worth to our enemies.

Hopefully by the end of this year I will have a vehicle that demonstrates my design in a real world application.

Now, if you have read this post check out this link. It is the first demonstration of my design, running on shop compressed air. You can see from the size of my hand how large it is. A wheel spinning at this speed would be doing well in excess of 100 MPH. Shop air has little energy compared to several thousand pounds of hydraulic fluid pressure.

http://www.youtube.com/user/Ride122609

We search for novelty in our quest for high efficiency.

The Patent Office has determined that this constitutes novelty. I would hope it deserves rational consideration.

regards
Mech

THIS CAR TRAVELS 75 MILES ON A SINGLE GALLON OF GASOLINE!

How much has been spent on battery developments since this was built?

How many billions of barrels of oil wasted?

How much CO2 in the atmosphere?

regards
Mech

Electric motors range between 80% and 93% under load.

Another example of a serial hybrid:

The FVT alé is the ICE version (a extremely efficient fuel vapor technology ICE, too) and it gets up to 92mpg.

The FVT eVaro is a serial hybrid that gets between 125MPGe and 325MPGe.
http://www.futurevehicletechnologies.com/4a.jpg

Source?

That's the thing, the electric hybrid also sees a similar improvement compared to stock. What it comes down to then is cost and availability. Whichever one is cheaper in larger orders will probably be what's used for the most part.
Maybe not, but we're looking at marginal returns here. A gas hybrid can easily double the mileage of a similarly sized car, ala a stock Prius versus a Camry. If we turn the Prius into a HH, we're not going to double the mileage again, but odds are we're going to more than double the cost. It's just diminishing returns. Now, if gas prices go up more, while costs go down, then alternatives may become financially viable, just like hybrids became viable this decade, but we aren't at the point yet.
HHs seem to suffer from the same issues EVs do. The cost doesn't justify the investment. Something like a Prius only carries a premium of a few grand over similarly sized vehicles, and it can reduce operating costs for the owner by well over a thousand bucks per year at the national average in terms of miles driven. Both EVs and HHs have a much higher premium and save the owner way less. Lets say an EV/HH has a ~$9000 premium over a hybrid. At best it's going to cut fuel costs by a third compared to a hybrid, and the reduction in brake wear is already present w/ a hybrid, so people are looking at a ~30 year payback compared to a hybrid, while a hybrid only has a ~3 year payback compared to a similarly sized conventional car.

Not fair. Turning a Camry into a Prius involves an aerodynamic rebody, just like the 75mpg (at steady state cruise) VW Bug hydraulic hybrid. The only apples-to-apples comparos on the market are Camry vs Camry Hybrid, and Civic vs Civic Hybrid. These hybrids have a 31% and 45% improvement in EPA Combined over their conventional counterparts.

What kind of fuel economy would that aero-Bug have delivered if they had used the same Tecumseh engine powering the rear wheels through just a tranny, instead of through two hydraulic motors and a hydraulic accumulator as they did?

Sources for your cost calculations roflwaffle?

EPA figures were substantially lower than yours.

regards
Mech

If we look at the exact same model, it still only increases the payback time to ~5 years instead of ~3 years. I'm comparing a hybrid to a conventional sedan, and then a hybrid to a hydraulic version of the same thing because those are/would be the best of what's available. Toyota doesn't make a non-hybrid Prius because it's a lot harder to take advantage of the aero and whatnot w/o a hybrid system.
If they had geared it properly, it would get slightly better highway mileage, and worse city.

The EPA estimates were a $7000 premium ($4000 over an electric hybrid) in high volume. We may see this a decade from now given the right set of circumstances, if the tech is viable, but currently, HH conversions runs around $13000, plus installation costs (Where the business makes their money). Hell, it's been over ten years since Toyota first commercialized an electric hybrid, and they still haven't reached a bottom in terms of a price premium even though they're getting pretty close at around $3000+ right now. Offhand, the high volumes needed for a $7000 premium, assuming HH tech is viable in that respect, are at least fifteen years away from the first production HH, just like they have been for hybrids. Arguably a manufacturer could hit ~$9000 ($6000 over an electric hybrid) in maybe seven to ten years, but we aren't even at the beginning of that w/ mass produced commercial HHs available.

I think the EPA designs (at least the ones that I looked at) were for a full sized SUV.

Not even close to what I am talking about, a 2000 pound 5 passenger vehicle.

In wheel drives that are individually self adjustable eliminate the swash plate hydraulic motors siamesed to the otherwise conventional differential in the EPA design. Reciprocating swash plate motors are notoriously inefficient at higher speeds, since they would be revolving at the same speed as a conventional prop shaft.

Accumulator costs are also greatly overestimated because they want to use composite construction which is totally unnecessary in a small vehicle that only needs around 6 gallons of high pressure fluid reserve.

Also their calculations are flawed in that their design does not use in wheel drives, so many unnecessary components are retained, and efficiency is reduced. They readily admit that the key component is a "new sheet of paper" design that is specifically used for HH applications.

In fact the close to 25% reduction in per vehicle components, elimination of close to 800parts in a conventional vehicle would result in a car that cost LESS than any conventional vehicle and considerably LESS than any electric hybrid.

Also eliminates the potentially costly battery, which even in a Prius of Insight 1 is a costly replacement. Also consider the planetary gear set in the Prius 'transmission" at $8000 replacement cost. In fact you could spend $15k replacing 5 individual part assemblies in a Prius (that are not serviceable with smaller individual parts).

It has already reached a point where the 10 year old hybrid used market sees a lower resale value, especially when mileages exceed 150k, and the complexity of electric hybrids becomes an issue.

In the future HH series design, the power train components will be virtually maintenance free. Most of the normal power train repairs will be a thing of the past, which is good, because the future repair scenario will be much more focused on the non power train components, in particular the accessories and electrical driven luxuries that are considered essential today by most buyers.

Comparing the EPA saimesed swash plate design to a good in wheel drive as linked in my first post of this thread is like comparing my a Model T to my civic VX.

regards
Mech

I would like to see a link where the EPA compared HH to electric in cost calculations. Maybe a copy and paste of the relevant info?

What I saw was a comparison to conventional vehicles. They did do a regenerative efficiency comparison, where the HH configuration beat the electric one by almost 300%.

regards
Mech

It was in my earlier post:

The 640 bhp MINI QED plug-in EV

You're missing the point. Most driving in America is commuting, most of which can be done on wall power ALONE.

No actually I'd say you are missing the point...

Since you could do all the commuting with a pure EV... Why put very expensive and highly inefficient hybrid parts in a car and then call it "more" environmental than the next car when in fact that can be highly questioned...

The argument here is also a bit silly... No, none of the many energy conversions in the chain in the hybrid is 100% efficient... Most are well below 50% efficient, so in comparasion to a ICE using top notch technology it's highly inefficient...

Old Mech... You seem to be agruing that a ICE coupled with a hydraulic transmission system (what you call a hydraulic Hybrid, with "motors" in the wheels) is more efficient than an EV?

Again... That is stupid... You are comparing apples and oranges... Of course a hydraulic transmission beats a mechanical, every day...
But calling that a Hydraulic Hybrid is just stupid... There are no hydralic motors there as far as I can figure... The hydraulic transfer the energy from the engine to the wheel, same as the mechanical parts do on any other car...

Now the hydraulic system is very efficient, but also expensive... If you couple it with a good ICE, you get a highly efficient ICE car... Not a hybrid... If you instead drop in an electric motor, you get an insanely efficient EV, since the electric engine is much more efficient than any ICE engine... Now bear in mind my wording... I'm talking energy in in one end, to the shaft out of the engine, not well-to wheel... well-to-engine out if you will...

Then stick on the hydraulics and the well-to-wheel number gets really good...

Ah "stupid" the name calling that disguises the ignorance of the person making the post.

I did not call it a Hydraulic Hybrid, it was many different organizations that apparently your lack of knowledge, reading, or understanding, of the system was your justification in hiding your ignorance with mud slinging and name calling.

But, for the sake of not letting this thread degrade into real stupidity. Lets look at your position.

A series hybrid is one that uses a single method of propulsion, which is the wheel motor in a HH. Now you could bypass the accumulator and drive the vehicle directly with hydraulic motors and not use any accumulator. The two sources of energy to drive the wheels make it a hybrid. Without the accumulator it is not a hybrid.

Maybe that was the pint your were trying to make, but you should drop the stupid comment because it makes you seem ignorant.

The term hybrid by definition is two sources of energy. You could argue that the engine is the only source of energy so it is not a hybrid, however when you take that position you would also have to eliminate the Insight and Prius in your descriptions of what is a "Hybrid", since both derive all of their energy from the liquid fuel you pour in the tank (in their original configurations).

At least in their stock configuration they have no provision for outside replenishment of anything but liquid fuel.

If you want to take the position that there are no hybrids (by your ignorance driven definition) then it doesn't matter to me, but you should consider the fact that calling someone stupid because of your own pitiful knowledge of the design just makes your position seem driven by stupidity since typically ignorance is curable.

Infinitely variable transmissions allow you to adjust the load on the engine by reducing its RPM to the balance point. If the load from driving the vehicle is insufficient then you store the energy in the accumulator. Once that level of storage is at maximum, kill the engine and drive the vehicle with accumulator pressure alone. That's self contained pulse and glide without speed variations.

Can your electric hybrid do that at 60 MPH? Maybe it they put a $10,000 battery in it, but even then it will not get good mileage because of the total losses through too many energy transformations, even when they are individually efficient, as well as the weight of the battery you must carry along.

That's pulse and glide, and you can do that with a hydraulic accumulator, BECAUSE of the total efficiency of the system. You can not do that with electric hybrids, unless you want to keep your speeds in the range of a fast bicycle.

If you want to brag about mileage and how good a hypermiler you are, just remember to also include the average speed of the trips you take. Any decent driver with 5 minutes of training can get 80 MPG in a 90 Civic if they average 22 MPH.

My average speeds are easily twice that amount, and in a lot of cases closer to 3 times that amount. My average mileage is between 55 and 60, with a lot of 300 mile one day trips that no BEV will do for at least another couple of decades without some major battery breakthrough that we have been waiting for, for 100 years.

If you want a $30,000 car that has a 100 mile range buy a Leaf, in a year or so, and use no oil whatsoever, if you can afford a part time car for $30k.

If you think when those BEVs get into the mainstream it is really going to cost you 2 cents a mile you are dreaming. Oh yes BEVs are not hybrids and it will be soon that you will be paying some form of road tax on your BEV, believe it.

Anyone here driven a BEV 20,000 miles? 50,000 miles? how about 100,000?

I think if you look at it rationally there is definitely a place for BEVs, I support their development.

I also understand their limitations. In a job hungry market a wage earner can not afford to limit their commute. They can also not afford to sell their house at a loss and move closer to a job that might not exist in a couple of years.

I would think from some of the responses that some followers of this thread have not read the linked articles in my first post.

They key component in a successful HH is the in wheel drive. Another key component is the overall simplicity of the system and its ability to capture and reapply huge amounts of energy with a virtually unlimited life expectancy, while being capable of reapplying those same amounts of energy at efficiencies exceeding 80% (again impossible with batteries and electric motors).

How much storage do your really need?

The Volt gives you 40 miles with a 400 pound fuel storage capability. The Leaf gives you 100 miles. Battery storage is still the achilles heel of the electric car, the same way it was the achilles heel 100 years ago.

Give me 300 miles for 200 pounds of battery storage with a 10 year life expectancy (required in California) and I will own only a BEV, especially if curbside charging is available (say in 15 minutes). It would be the only car I need, instead of two cars, one for short distance and the other for trips.

No one knows how long it will be before that is available, but at 59 I may not see it in my lifetime.

The first generation of HH will be a launch assist axle with a small accumulator, in the rear axle of a small FWD car. It will get better city mileage than highway mileage, whicle retaining the conventional power train.

The next step will be to use the same launch assist axle to pulse and glide the vehicle (engine on-engine off)at most speeds up to about 60 MPH, while still retaining the conventional powertrain.

This can be done with a cost to benefit ratio that pays for itself in months, not years.

As the technology matures the dedicated (no conventional powertrain) can be the next eveolution of the system. When you rationally consider the components eliminated the cost is actually less than conventional and the benefits immediate with no break even point to even consider.

Read the links, thats not my data.

regards
Mech

Toyota is paying royalties on the transmission in the Prius that they stole from a comapny in Florida that patented the system before Toyota ever used the same design.

regards
mech