Honda’s IMA hybrid car technology uses an electric motor mounted between the engine and transmission to act as a starter motor, engine balancer, and assist traction motor. In its first generation, IMA did not function to power the car on electricity alone, and could only use the electric motor to assist or start the ICE. Beginning with the 2006 Civic Hybrid model, control software changes facilitated activation of the IMA electric motor in the EV (Electric Vehicle) mode while the vehicle is coasting without activating the ICE.

Compared to Toyota’s Hybrid Synergy Drive (HSD) or the GM/Daimler-Chrysler/BMW Two-Mode (2Mode) Hybrid, the IMA Hybrid has a less powerful motor-generator. The smaller motor-generator permits the IMA Hybrid to slow or stop its rate of deceleration by a lesser extent compared to the HSD and 2Mode hybrids equipped with larger motor-generators. Additionally, the IMA- Powered Hybrid cannot operate without turning over the ICE, which is directly coupled to its electric motor.

The IMA Hybrid system as installed in the Honda Civic Hybrid (HCH), delivers an approximately 63% increase in CITY DRIVING fuel economy over what the 1.3 Liter I-4 HCH ICE would deliver were it utilized to drive the Honda Civic chassis in a non-hybrid, conventional gasoline-powered application.

3. TWO-MODE HYBRID: The Two-Mode (2Mode) Hybrid Solution was jointly developed by General Motors/Daimler-Chrysler/BMW to power heavy curb-weight, large mass-transit “city bus” sized vehicles. Its Two-Mode design means it is not a “Full-Time” hybrid drive system. It was developmental test and evaluated and “Pilot Tested with Limited Field Deployment” in the 1990s. As part of this Pilot-Limited Field Deployment, a few hundred city mass-transit buses were put into service in selected cities, mostly in Europe, but otherwise it was shelved without broader follow-on deployment and expanded application into private passenger vehicles until recently.

Although it had been shelved by General Motors Corporation prior to the New Millennium, when $100-per-barrel oil approached and $3.00+ per gallon gas happened, GM quickly resurrected and re-embraced the “Mass-Transit Bus-Sized” Two-Mode gas-electric hybrid power solution. They quickly brought it down off the shelf, dusted it off and down-sized and tamped it into and under the hoods of their Full-Sized 2008 GMC Yukon/Chevrolet Tahoe "Family Bus-Sized" SUV Trucks to power these mega-tonnage Gas-Guzzling “Beasts.” In addition, at the Washington Auto Show in January 2008, General Motors Corp. announced it had received orders for 1,732 Two-Mode (2Mode) Hybrid buses from transit agencies in Washington, Philadelphia and Minneapolis/St. Paul.

The Two-Mode (2Mode) Hybrid System employs a special electronically variable transmission (EVT) with two integrated motor-generators along with using special fuel saving ICE technologies that include cam phasing, variable valve timing (VVT) and Active Fuel Management™ cylinder deactivation technologies. These elements working together, deliver an overall improvement in fuel economy over the equivalent non-hybrid Yukon/Tahoe versions of 40% to 50% City MPG/25% Highway MPG. Two-Mode (2Mode) Hybrid Yukons/Tahoes are now being offered in limited availability qualities for Model Year 2008 with a Two-Mode (2Mode) Hybrid version of the Saturn Vue being offered in 2009.

Although the 40% to 50% City MPG/25% Highway MPG improvement is a good improvement in fuel economy on a percentage basis, the Two-Mode (2Mode) Hybrid Solution comes in a distant third compared to the HSD and ISA enabled gasoline-electric hybrid vehicles on total delivered miles per gallon fuel economy. The HSD and IMA used in the 51/55/60 MPG Prius and 46/48/51 MPG Civic deliver twice to three times the MPG-FE that is delivered by heavy curb-weight Two-Mode Hybrid enabled truck-sized 21/21/22 MPG Yukon/Tahoe vehicles.

The “Two-Mode” designation comes from the hybrid’s two operating modes that can function singularly or in parallel. One mode is optimized for city driving and the other for highway driving. Under light loads and at low speeds (City Mode), the Two-Mode system can operate either on its electric motors and battery pack or on internal combustion engine (ICE) power alone, or using a combination of the two modes. At higher speeds and with heavier loads (Highway Mode), The Two-Mode (2Mode) Hybrid System switches to the second mode that runs mainly on the gasoline engine with electric motor-battery available and assisting as and if needed for added power to climb steep grades, tow a trailer, or for added acceleration oomph during passing.

Any and all “hybrids” you may see being offered/planned to be offered by General Motors/Chrysler-Dodge/Mercedes/BMW in the upcoming model years, will be based around and incorporate this Two-Mode (2Mode) Hybrid System that was jointly developed by GM/Daimler-Chrysler/BMW to power heavy curb weight SUVs and "bus-sized" heavy-vehicles.

4. SATURN “GREEN LINE” MILD-HYBRID: This “Green Line” hybrid solution is called a “Mild Hybrid.” It comes in last and resides at the bottom of the hybrid technology barrel. It is what I call a marketing solution that was cobbled together as General Motors Saturn Aura/Vue and Chevrolet Malibu were scrambling to become “Eco-Green” and “Fuel-Efficient” overnight. They had their engineers throw together a quick and dirty "Battery-Alternator" motor-generator “techno-kludge.” This "Mild Hybrid" solution is essentially an over-sized car-battery that permits the “Hybrid” Saturn Aura/Vue and Chevrolet Malibu to run off their batteries for short periods.

The Green Line "Mild-Hybrid" Belt Alternator Starter (BAS) system basically functions like a battery-alternator powered turbo-charger, providing some extra oomph to the gasoline engine when needed through a large "starter motor." It uses a Belt Alternator Starter (BAS) system that employs a special oversized "starter motor" in combination with an oversized, up-voltaged 36 Volt car battery (i.e. essentially electrically equivalent to three (3) standard 12 V car batteries connected in electrical series, 12V + 12V + 12V = 36V). The Battery-powered Alternator-Starter is used to assist and mechanically turn over the non-operating internal combustion gasoline engine (ICE) and power the vehicle until a certain "Start-Up" RPM level is reached. Once "Start-Up" RPM is reached, the ICE "fires-up" and operates using the conventional "Otto Cycle" to power the car.

As with a typical starter motor, the electric motor in the "Mild-Hybrid" BAS is not connected directly to the main driveline power train. The gasoline engine starts operating at a higher speed than it normally would without the BAS Assist. Overcoming initial starting inertia and moving the vehicle without using fuel is how "Mild-Hybrid" BAS System works to save fuel. In addition, fuel to the ICE is automatically shut off and the ICE shut down when the vehicle is coasting, braking or stopped.

The Green Line "Mild-Hybrid" BAS installed in the Saturn Vue/Aura and Chevrolet Malibu does seem to provide some small improvement in fuel economy (approximately 10%), while keeping complexity to a minimum.

There, I have given you a brief overview tutorial on gas-electric hybrid vehicles offered/being offered here in the U.S.

FIRST, THE BAD NEWS: If you choose to drive your new hybrid car using the same Gas-To-Go/Brake-To-Stop driving techniques used to drive the conventionally powered car it replaced, your miles-per-gallon fuel economy numbers will not be remarkable. The MPG-FE numbers probably will be as if it was being solely powered by the conventional gasoline powered Internal Combustion Engine (ICE) installed in it to power the ICE portion of the hybrid gasoline-electric propulsion system.

I once owned a 1992 Honda Civic CX. It was conventionally powered by a standard "lean-burn" 70 hp gasoline-powered Honda In-Line 4-Cylinder "Otto Cycle" ICE which delivered an EPA 42 City/45 Combined/48 Highway Estimated MPG and 41 "Around Town"/48 "Open-Road," as measured by me using the Multiple-Tank-Refill Method.

The gasoline-powered portion of the Prius Hybrid Synergy Drive system is powered by 76 hp Toyota In-Line 4-Cylinder ICE, operated on the "Atkinson Cycle." Toyota's 76 hp In-Line 4-Cylinder ICE is similar in size, weight and power to 70 hp Honda Civic CX ICE. This means that the inherent, nominal gas mileage of the Prius In-Line 4-Cylinder ICE is probably the same as the 41/48± MPG delivered by the ICE of my old Honda Civic CX.

Therefore, if your Prius is delivering less than or equal to 41-48 MPG-FE, you probably are driving your gasoline-electric Prius hybrid using the same fuel consumption inefficient driving techniques you use to operate 100% conventionally powered cars. The consequences of your "hybrid unfriendly" driving habits and operating techniques are that you are effectively "bypassing/overriding" the fuel economy contribution benefits available from the electrical energy regenerating, recovering and storage portions of the gas-electric hybrid system.

Continuing to use such old, “hybrid unfriendly” driving techniques and not driving “hybrid smart” will prevent you from “reaping” the incremental fuel economy “harvest” that is available from the battery and regenerative motor-generator and braking elements of the hybrid gasoline-electric system design.

A BIT MORE NOT SO GOOD NEWS: Unfortunately, most drivers lack the inclination, dedicated driving discipline and frugality required to “work” at learning to optimally drive their hybrid car, as a hybrid car must be driven to facilitate it delivering its maximum fuel economy benefits and truly stellar real-world MPG.

Most first-time hybrid car owner-operators lack prior knowledge on optimal operation of a hybrid vehicle. As a result, when they pick their new hybrid up at the dealer and drive it off the lot, they do so using the same Gas-To Go/Brake-To-Stop manner they used driving the old 100% conventionally powered autos their new hybrid car replaced. These conventional foot throttle pedal punching and brake stomping Gas-To-Go/Brake-To-Stop driving techniques used to operate “conventionally powered” vehicles are the same ones most drivers have used ever since they got their driver’s license in high school and first started driving.

Bottom-line --- Driving hybrid cars with a heavy gas throttle and brake pedal foot will result in poorer miles-per-gallon/liters-per-100 kilometers fuel economy as compared to if they are driven in a “hybrid friendly” manner.

NOW, THE GOOD NEWS: The good news is that even if a driver operates a hybrid car like he or she is still driving their old conventional, 100% Internal Combustion Engine (ICE) powered car, it will still deliver “GOOD” MPG-FE, just not "STELLAR” MPG-FE as defined by the EPA MPG-FE estimates. This is because Toyota, Honda and General Motors engineers have optimized the design of the Hybrid Synergy Drive (HSD), Integrated Motor Assist (IMA), "Green Line” Belt Alternator Starter (BAS) "Mild-Hybrid" and Two-Mode (2Mode) gas-electric drive-system control hardware and software of their hybrid vehicles around the driving behaviors and expectations of a "typical driver.” Of course, their assumed "typical driver” is one who only knows how to drive and is experienced in driving an Internal Combustion Engine (ICE), 100% conventionally-powered vehicle.

To get your hybrid vehicle to meet or surpass the EPA MPG-FE estimates, you have to "learn" to let the HSD, IMA or other hybrid do the job it was designed to do by "staying out of its way" and not using old "energy robbing" driving behaviors and techniques. You will find that adding, integrating and unobtrusively applying new hybrid-focused driving behaviors and top-level, elemental Hybrid Hypermiling Driving Techniques into driving your gasoline-electric hybrid car is a reasonably painless process. Your efforts will be rewarded with delivery of "stellar" MPG-FE and not having to "pay at the pump" as much or as often as you did before you started driving your hybrid vehicle.

The more you learn to "drive hybrid smart," and work as an integral part of the HSD, IMA, "Green Line" BAS, Two-Mode (2Mode) or other hybrid system solution and their various features, the more you will converge on meeting or surpassing the EPA Miles Per Gallon (MPG) Fuel Economy (FE) numbers promised on your hybrid "fuel-sipper" of choice's window sticker.

LEARNING TO DRIVE "GREEN" TO $AVE "GREEN BACK" PETROLBUCK$...$$$$: Face it, gas prices will likely never be going down. They never have in the past and will probably not start now.

Whether we realize it or not, we all are now driving under a new fuel consumption paradigm because gas is selling for $4 per gallon not 25¢ as it was when the fuel wasting on-road driving behavior norms of today were formed. I recognized this paradigm shift back when gasoline was still selling for under $1.499 per gallon. At that point, I changed the driving and fuel consumption behaviors and techniques under which I operate my vehicle and transformed myself into a Hybrid Pseudo-Hypermiling Zen Master.

With $140± per barrel oil and $4.00± per gallon gasoline in pursuit of $6, $8, $10+ and beyond, most of us out here in the Yankee Doodle hinterlands want to drive to save "Green" and will do anything "legal" to save a "Green Back" PetrolBuck. I have learned how to assist my Prius in delivering Green Back $aving, "$tellar" MPG-FE to me.

I employ a combination of fuel economy enhancing "in-garage" pre-operative set ups along with "on-road" operative Hybrid Hypermiling Driving Techniques to pre-operatively set up and operate my 2G, Generation II Prius to achieve money saving MPG-FE performance. My Hybrid Pseudo-Hypermiling assures that I regularly meet or beat the old Pre-2008 51 Highway/55 Combined/60 City EPA Estimate MPG-FE numbers. Yes, it does require a bit of "Hybrid Driving Work," that for me has become second-nature "Hybrid Driving Play"... or should that be "Hybrid Driving Pay"... as in "Pay Day."

My Hybrid Hypermiling enhanced driving is saving and "Paying" my family and me "Big PetrolBucks" by minimizing our family’s monthly "fuel burn rate" and total annual gasoline fuel expenses. Hybrid Pseudo-Hypermiling has reduced the monthly auto fuel expenses for my family's primary transportation vehicle by ~80%. At today's $4.00± per gallon of gasoline prices, this has reduced the projected annual fuel expense for our primary transportation vehicle from $4310± down to $890±. The ~$3420 savings makes the Family CFO, my wife, "Hybrid Happy."