PHEV Cost Benefit Analysis

Q: What are the primary benefits of a PHEV conversion?Installing a plug-in Prius conversion kit significantly reduces fuel consumption and green-house gas emissions from your vehicle. It’s tangible insurance against spikes in the cost of gasoline and much cheaper than buying a brand new car. It will also retain value that can be factored into the resale price of the car. Finally, it’s available now, and is the only crash-tested, safety-approved plug-in conversion option on the market.

Q: How much will a PHEV conversion improve my car’s mileage?On average, this conversion kit will double the fuel economy of your Prius. That means that for every gallon of gas you currently use, you will save a gallon of gas post-conversion. A driver getting the EPA estimated 46 mpg for the Toyota Prius should get around 100 mpg post-conversion.

Here’s another way to think about it: If you flip miles per gallon to gallons per mile, it’s easy to understand — the standard Prius uses 2 gallons of gasoline to drive 100 miles. A newly converted plug-in hybrid using this conversion kit will use about 1 gallon of gasoline to drive 100 miles.

Prius Conversion Pricing Information

• Standard Price for Prius Conversion: $12,500
• After 10% Federal Tax Credit: $11,250

Prius Conversion Specs

Here are several examples of mileage improvements from the A123/Hymotion. Mileage Calculator:

MPG Calculator
city/fwy drive ratio	1-way commute	plug-in @ work?	commute miles/yr	total miles/yr	avg mid- size car	Standard Prius	Plug-in Prius	Gas Station Trips/Year
33/67	30	No	15,000	18,000	25	46	82	18 vs 33
33/67	30	Yes	15,000	18,000	25	46	100	15 vs 33
33/67	20	No	10,000	13,000	25	46	100	11 vs 24
33/67	20	Yes	10,000	13,000	25	46	100	11 vs 24
33/67	40	No	20,000	23,000	25	46	73	26 vs 42
33/67	40	Yes	20,000	23,000	25	46	100	15 vs 33

Note: These calculated mileage estimates apply under optimal driving and road conditions.

Q: Why do I have to use gas at all? Doesn’t this conversion make my Prius an Electric Car?Your converted Prius will not be a fully electric car, since it’s still a hybrid (now with a much bigger battery), but it will be a better and much more efficient plug-in hybrid electric vehicle. A converted hybrid will still rely on a gasoline motor under certain circumstances. These include:

• Rapid acceleration
• High Speeds
• Cold weather
• Hills

Green Gears customers report these ‘real world’ mileage ranges for typical commuting scenarios:

Average/typical commute, less than 30 miles each way:

• Home charging only: Average 70-90 mpg
• Home and work charging: Average 70-120 mpg
Longer commute (30-50 miles each way)
• Home charging only: Average 60-70 mpg
• Home and work charging: Average 70-90 mpg

Users report 80 mpg for short drives around the city after charging.

Driving style accounts for about 30% of mileage fluctuation (on the same drive cycle Driver A can get 70mpg, and Driver B can achieve 100mpg). Some have reported well over 100 MPG. ‘Eco-drivers’ that now get 70 mpg with their standard Prius can achieve 130+mpg with their new Green Gears Hymotion Prius PHEV. Very extreme Hyper-milers have achieved 2000 miles on a single tank of gas!

The Green Gears Eco Driver training tips that are included in the purchase of your Hymotion Plug-in Conversion Module will help you learn how to maximize your mileage, and thereby also minimize your carbon emissions.

Q: How much will my car’s green-house gas emissions decrease post-conversion?

Co2 Emmissions Calculator
Standard Prius compared to Plugin Prius	Total Miles/Yr	Average MPG	Carbon (#) Emissions/Yr	Mature Trees* Req’d/Year to Offset
Standard Prius	18,000	46	8088	1260
Plugin Prius (1 chg/day)	18,000	82	4537	707

*Number of mature sugar maple trees required to offset CO2 emissions produced each year. Source: http://www.travelmatters.org/calculator/individual/

Q: What is the driving range on a single charge?It’s important to understand that the advantage of converting your Prius into a plug-in hybrid is not to make it an all-electric vehicle, but to make it a better (and much more efficient) plug-in hybrid electric vehicle—a true state-of-the-art PHEV. Under typical driving and road conditions, your newly converted Prius will provide electrical driving assistance for 30 to 40 miles from a single charge. Over those 30 – 40 miles, you can see fuel economy of up to 100 mpg in either city or highway use, depending on your driving style, terrain and road conditions. For around-town driving, it’s relatively easy to keep your Prius in all-electric (EV) mode once you get the hang of things, but it does require speeds under 35 miles per hour and light acceleration. Pure all-electric mode range is 10-15 miles, but it’s generally not possible to keep the car in EV mode until the battery is depleted—the Hymotion kit will kick in to provide a ‘blended’ 30-40 mile range. Note that the Prius All-Electric Mode (EV mode)—when your Prius is entirely powered by its electric motor and the gasoline engine is off—is an operational mode programmed into the Prius computer. The All-Electric Mode is generally not accessible to American drivers due to the absence of the engine kill-switch EV mode button in the Prius sold in the US.

Q: Do I need special equipment to charge the car once it’s converted?No. All you need is a standard extension cord and wall outlet.

Q: How long does it take to fully charge the Hymotion battery?Charging will take about 5 1/2 hours at 110v. This equals 5.5 kilowatt-hours (kwh) of electricity.

Q: How much does it cost to fully recharge the battery?Let’s use Pacific Gas & Electric, a major West Coast utility, as a typical utility provider. PG&E rates are tiered, with 5 tiers. Your cost of electricity is determined by amount used per month, starting with the lowest residential baseline rate of $.09/kwh. At $0.10/kwh, a full charge will cost about $0.55. Just multiply the cost of electricity in kilowatt-hours (kwh) x 5.5 kwh (the battery size):

	Tier 1 (Baseline)	Cost: 5.5 KwH to Charge	Tier 5 (Highest)	Cost: 5.5 KwH to Charge
PG&E Rate	Rate/KwH	Plug-in Prius	Rate/KwH	Plug-in Prius
Residential Rate	0.09	$0.50	0.44	$2.42
Time of Use (Solar)
Peak	0.29	$1.60	0.61	$3.36
Off Peak	0.05	$0.28	0.22	$1.21
Low Emissions Vehicle
Peak	0.29	$1.60	0.61	$3.36
Off Peak	0.05	$0.28	0.22	$1.21

Q: What’s the average cost to charge a plug-in Prius Module in San Francisco, at PG&E utility rates?Using an off-peak rate of 14 cents per kilowatt hour, completely charging your plug-in Prius would cost just 77 cents.
What if I charge my PHEV at night at my home?
Very low residential electric rates are available with time-of-use meters—typically $0.05 per KwH from midnight to 6AM. So, if you charge your new Green Gears Plug-in Prius from 12AM to 6AM, your cost can be as low as $0.28 per charge.

Q: Will the new battery recharge when I brake?No, the battery will only charge when you plug it in. Only the standard Prius battery can be recharged by braking (or by the gasoline engine).

Q: Can I charge the battery faster from a 220V (dryer outlet)?No. This conversion is only designed for a standard 110V outlet.

Costs and savings aren’t just about money. Learn about the Environmental Benefits as well.