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I think we're losing sight of some dinimshing retruns here. TO get more range and speed, you quickly need much larger motors and batteries. IF the car isn't custom built for that function, you're adding a lot of weight, taking up a LOT of space. THere's a reason the Prius, Volt, Insight are all compact cars. I think you'll be surprised at how large a battery you need with a full size IC engine and with full regenerative braking.

We also could get people to just buy smaller cars and not live 40 miles from work. I only drive 6000 miles per year or less. A guy that drives 15,000 miles per year might get almost 2X the mileage, but still consumes more fuel.

Maybe it should considered this way. Without regenerative braking, you will overall consume MORE energy with this system. You are simply deferring some of it to the grid. This is more like a hydrogen system.

I'm highly skeptical until this system replaces all 4 brake rotors and is integrated with the transmission and engine computer to optimize it as it is in current hybrid electrics.

I hate to day it, but high and sustained fuel prices are the best way to drive innovation and make consumers desire more fuel efficient vehciles . Last I checked, large SUV's, full size trucks were still selling well. One BIG sep forward is that midsized cars are now starting to match and in some cases exceed the economy of smaller compact cars... at least on the highway where they are used the most.

IF we stopped supporting these s*** hole countries with benefits and subsidies to better secure their oil supplies and instead let the open market do it's thing. I think plug in electric hybrids with a small CNG could be a viable option as well.

Also if we were really serious, we might impose lower speed limits for vehicles over 3000lbs or with fuel economies under 40mpg combined similar to trucks. Then also raise fuel taxes a little higher and specifically target those funds for subsidising the purchase of electric vehicles.

I think this is a great idea. If they could get the top speed up to 45 mph and the range around 30 miles a lot of people would buy if gas prices keep going up. You would basically have an electric car for commuting to work that could run on gas for longer trips.

The USA has plenty of power plants to turn coal and nutrons into electrical power. They just kinda cruise at night when power is not required. We need to figure out how to push cars around with this power instead of buying oil from the crazys in the mid-east.

Originally Posted by motoguy128

IF you have regenerative braking, how hard you accelerate becomes irrelevant and in some cases you need to accelerate harder for best overall system efficiency.

But I agree, driving technique makes a big difference. However my time is worth more than saving a few cents. SO I drive 5-10mph over the limit but I do pay attention to timed lights. However occassionally some are off sequence and it drives me nuts when someone is going 5 under or right at the speed limit when I know that going 2-3mph over will allow you to "make" a light vs. sitting for 2 minutes.

Plus in residential area (when no children are around) going 30mph yields better mileage than 25mph.

True. Rate of acceleration has much less to do with energy waste in electric motors. But excessive speed is wasteful, even when some of the energy is recovered. And for those who like to drive fast, RB provides a rationalization for their bad habits. It does not justify them.

You might beat traffic at a yellow light, but it will all catch up to you at the next light.

There was an experiment done several years ago about driving habits and time saved. Two drivers drove across the city of Chicago. One drove at or below the speed limit, seldom changed lanes, and stopped at yellow lights whenever possible. The other drove above the speed limit, changed lanes often, and ran yellow lights. I don't remember the exact result, but the fast driver beat the slow driver by about 2-3 minutes (a little over a minute per hour). What did he accomplish? How many lives did he endanger? What happened to his gas mileage? How much extra wear and tear to his car did he cause? How much stress did he endure? I don't have the answers to these questions, but I suspect they were all negative.

I have no desire to prove how many pennies you might save with good driving habits. My only point about RB is that it is most useful for those drivers who spend a lot of time slowing down. If you spend a lot of time slowing down, RB provides a way to recover some of the energy you wasted. But if you prefer to drive at a constant rate, RB provides less benefit.

The people who will benefit the most from RB are bad drivers. With RB on their cars, they will feel more encouraged to continue their bad habits. But they will accomplish little beyond endangering the lives of others and causing excessive wear to their cars.

IF you have regenerative braking, how hard you accelerate becomes irrelevant and in some cases you need to accelerate harder for best overall system efficiency.

But I agree, driving technique makes a big difference. However my time is worth more than saving a few cents. SO I drive 5-10mph over the limit but I do pay attention to timed lights. However occassionally some are off sequence and it drives me nuts when someone is going 5 under or right at the speed limit when I know that going 2-3mph over will allow you to "make" a light vs. sitting for 2 minutes.

Plus in residential area (when no children are around) going 30mph yields better mileage than 25mph.

Originally Posted by motoguy128

THe answer gets a little complicated. The reason accelerating fast consumes more energy is similar to who AC units and chillers are more efficient at part load. Under normal loads, IC engines in cars are most efficient at lowers RPM's and partial throttle positions. They burn the most lean and more improtantly, make full use of their compresssion ratio. Meaning that more energy goes into moving the piston and less into waste heat. At full throttle and high RPM, the mixture is more rich, and sice throttle positon is larger, more air is pushed into the piston, so pressures and heat increase and more energy is lost to waste heat.

However, on a electric motor and drive, the permenant magnet motors used make peka torque at 0 RPM and there's little change in efficinecy as RPM increases. However, the drive, is most efficient at full load. At part load it uses I beleive pulse width modulation and some waste heat is created switching on/off the circuits. So you want the electric motor at full load, but the IC engine at minimum RPM and throttle and more improtantly, if it's a automatic, it needs to have the torque converter locked up.


Oh... and jsut ot further comlicate matters, engine effciency and fuel economy are not nessesary the same thing. Efficiency would be fuel conmption rate per delivered HP. Fuel economy is fuel consumed per unit of distance traveled. Many engine reach peak efficiency I beileive right at the point where the torque curves begins to taper off.


OH and in reality, the instanataneous fuel consumption of a engine varies much more dramatically. Very lgiht throttle at low RPM's on a small 2.5L 4 cylinger for example is probably around 50mpg, but full throttle near redline is around 8-10mpg. AN IC engien at idle probably only makes about 5-10HP depending on throttle positon, AC and alternator loads. At a highway crusing speed of 65mph @ 2000RPM and part throttle, it's probably around 40HP and at a nice efficient 45mph, its' maybe just 20HP at 1500RPM.

That's all well and good, but:

1. I used the example of the gas engine because it's something we are all familiar with. It's easier to talk about miles per gallon than watts per foot-pound per revolution or some such ratio. Of course gas engines are less efficient and have different power curves. But in this case, that's beside the point. I was merely illustrating a point, not carrying on a scientific discourse or comparing efficiency ratios.

2. A lead foot is a lead foot. If you are driving in a 30 mph zone and zoom up to 50 so you can pass a slowpoke and beat him to the red light and stomp on the brakes, while I drive 25 and arrive at the light a few seconds after it has turned green and barely take my foot off the gas, you have wasted more energy than I, regardless of engine type, and regardless of regenerative braking. (Yes, I am one of those guys who gets a kick out of passing lead-footers at the light. In a series of ten traffic lights, I'll pass the same idiot ten times (in light traffic). I've even had people pull into parking lots behind me to tell me my brake lights didn't work.)

Originally Posted by Space Racer

Let's say you are driving a hybrid car with RB whose battery is low, so it only uses the gas engine. The engine gets an average of 30 mpg when you are light on the gas pedal, and 20 mpg when you are heavy on it. The advantage of having a heavy foot is that there is a good amount of wasted energy, and some of it is used to recharge the battery. With a light foot, there is little wasted energy.

Would you drive with a heavy foot or a light one?

THe answer gets a little complicated. The reason accelerating fast consumes more energy is similar to who AC units and chillers are more efficient at part load. Under normal loads, IC engines in cars are most efficient at lowers RPM's and partial throttle positions. They burn the most lean and more improtantly, make full use of their compresssion ratio. Meaning that more energy goes into moving the piston and less into waste heat. At full throttle and high RPM, the mixture is more rich, and sice throttle positon is larger, more air is pushed into the piston, so pressures and heat increase and more energy is lost to waste heat.

However, on a electric motor and drive, the permenant magnet motors used make peka torque at 0 RPM and there's little change in efficinecy as RPM increases. However, the drive, is most efficient at full load. At part load it uses I beleive pulse width modulation and some waste heat is created switching on/off the circuits. So you want the electric motor at full load, but the IC engine at minimum RPM and throttle and more improtantly, if it's a automatic, it needs to have the torque converter locked up.


Oh... and jsut ot further comlicate matters, engine effciency and fuel economy are not nessesary the same thing. Efficiency would be fuel conmption rate per delivered HP. Fuel economy is fuel consumed per unit of distance traveled. Many engine reach peak efficiency I beileive right at the point where the torque curves begins to taper off.


OH and in reality, the instanataneous fuel consumption of a engine varies much more dramatically. Very lgiht throttle at low RPM's on a small 2.5L 4 cylinger for example is probably around 50mpg, but full throttle near redline is around 8-10mpg. AN IC engien at idle probably only makes about 5-10HP depending on throttle positon, AC and alternator loads. At a highway crusing speed of 65mph @ 2000RPM and part throttle, it's probably around 40HP and at a nice efficient 45mph, its' maybe just 20HP at 1500RPM.

IF it looks at hte primary IC engine throttle position, speed and RPM, it could have some potential. Although it seem like at minimum it also need soem regenerative braking funciton or at least a option to upgrade your existing alternator to provide some recharging when the IC engine load is below a certain threshold... such as when braking or coasting.

Overall, I struggle to see a payback. I might be insterested in a smaller, cheaper version just to add AWD to my wife's sedan.

So how do you install the thing? You'd have to repalce the whole hub assembly.


Any mention of the impact on adding 5+lb of unspring weight to yoru suspension? That could result in some major impact to wheel control and handling.

MFG's have tried these kinds of "soft hybrids" before. They suually add abotu $5k to the rpice and only increase city mileage by a moderate amount. Not enough to justify it. The big selling point is usually increased acceleration. Honda sold one for 2 or 3 years on the Acord than cancelled it. Saturn had it on one of their vehicles I think too.

Originally Posted by billygoat22

on highway driving, regenerative wouldn't be much help, but regardless of how inefficient acceleration was, still the same amount of energy in a moving vehicle at a specific speed. and you would be recycling "used" energy, rather than consuming new when you started moving again.

Let's say you are driving a hybrid car with RB whose battery is low, so it only uses the gas engine. The engine gets an average of 30 mpg when you are light on the gas pedal, and 20 mpg when you are heavy on it. The advantage of having a heavy foot is that there is a good amount of wasted energy, and some of it is used to recharge the battery. With a light foot, there is little wasted energy.

Would you drive with a heavy foot or a light one?

on highway driving, regenerative wouldn't be much help, but regardless of how inefficient acceleration was, still the same amount of energy in a moving vehicle at a specific speed. and you would be recycling "used" energy, rather than consuming new when you started moving again.

Originally Posted by Space Racer

It's designed to run at the same time as the gas engine. It shares the work. There's no need to disengage it when the car is traveling less than 40mph.

I just do not see this as saving any substantial amount.

I am no expert, though.

Originally Posted by billygoat22

maybe they can do regenerative braking as a plug-in add-on? Seems like a waste of time if that isn't available.

Regenerative braking (RB) is cheaper than grid electricity, but grid electricity is a lot cheaper than gasoline.

But consider this: Regenerative braking occurs when the car is traveling too fast for the task at hand. It's a way of recovering part of the energy that was spent on acceleration. Most RB occurs in stop-and-go traffic. Light-footed drivers will have little use for it.

If a car with RB manages to recover a substantial amount of energy from braking, it's only because a larger quantity of energy was wasted on acceleration in the first place. Accelerating slowly is more efficient than accelerating fast and relying on RB for a kickback.

Originally Posted by pacnw

so if it does not tie into the gas engine in any way, it cannot save you any money.

it must either run independent of the engine until 40 MPH stated cut off or disengage the drive shaft to keep from using the engine from powering one set of wheels and the electric from powering the other set.

It's designed to run at the same time as the gas engine. It shares the work. There's no need to disengage it when the car is traveling less than 40mph.

maybe they can do regenerative braking as a plug-in add-on? Seems like a waste of time if that isn't available.

so if it does not tie into the gas engine in any way, it cannot save you any money.

it must either run independent of the engine until 40 MPH stated cut off or disengage the drive shaft to keep from using the engine from powering one set of wheels and the electric from powering the other set.

not too sure of the commercial application-weight/size of vehicle.

Originally Posted by chaard

So is it just turning a 2wd into a 4wd? Does the gas engine disengage under 40mph? So you might save $4gal/day. How much is the electric charge going to cost?

It's not just for front wheel drive cars. It works on rear wheel drive cars, too.

It has no control over the gas engine.

It's a power assist. It's like driving a car downhill. It's like putting an electric motor on a bicycle.

The neat thing about it is you don't have to buy a whole hybrid car. You can just buy a kit. And while it's not quite as efficient as a purpose-built hybrid car, it's a lot more efficient than gas by itself, and a lot smarter than ethanol or total EV.

So is it just turning a 2wd into a 4wd? Does the gas engine disengage under 40mph? So you might save $4gal/day. How much is the electric charge going to cost?

If the price was $9000, no one would buy it. The inventor must have a lower price point in mind.

The motor is basically a rotor assembly that fits between the brake drum/rotor and the wheel. Installation should be pretty straight-forward.

$3000 is the total retail price of the parts used to build the prototype. Wholesale prices and mass production would keep the cost down. Production would not have to start from scratch. The patent could be licensed to an existing motor manufacturer.

I would expect installed price to be somewhere around $4000 to $5000 at first, and quite a bit lower after two or three years.

If you save a gallon of gas a day @ $4.00/gal, it would pay you back $1000/ year. (Similar calculation.)

They might not guarantee it on a commercial vehicle. Who knows?

On-board charging technology would jack up the cost, wouldn't it? They might be able to provide it as an option after more development.

I read this the other day, it sound very interesting but will it be practical. They said $3000.00 in parts so jack that price up by 150% to cover markup marketing and profit then add labor to install it. Let's just say $9,000.00 for an average vehicle it will take 8 to 10 years to pay back driving twenty miles a day 5 days a week under 40 MPH.

Will it work on a service truck pay back would be quicker but only for 40 miles a day. I am not raining on anyone parade just thinking out loud. Hey I would love 400 ft-lb's. of torque on my F-150 running around town and not using gas.

I wonder why they do not have an onboard charger.

$3000 Plug-In Hybrid Retrofit Kit fits almost any vehicle

This device isn't in production yet. It still has a lot of testing ahead. But it looks like it will make it easy to convert any gas-powered vehicle into a plug-in hybrid. (It doesn't recharge its battery when it's on the road.)

It puts a motor at each rear wheel and a battery in the trunk.

http://www.wired.com/autopia/2012/08/hybrid-conversion/