Assume the following: Hybrid MPG: 54 Electric MPG: 25 Battery size: 8.8-kWh Cost per kWh: 12.5 cents (PG&E in Nor Cal; cheapest rate) Gallon of gas: $3.00 Hybrid Mode: Cost to travel 54 miles: $3.00 Electric Mode: Cost to fill up for 25 miles: 12.5 x 8.8 = $1.10 Cost to travel 54 miles: 1.1 x 2 +..08 = $2.28 I think the math is roughly right. So you save money, but not that much. Roughly 25%.
Even though the battery is 8.8KWh, it does not drain 100% in the 25 miles you go with each charge. A number of us have meters that monitor the energy required to recharge the battery and never see it hit anywhere close to 8.8KWh. My typical full charge is just above 6KWh. Others have reported up to about 6.3KWh... Using 6.3KWh, per charge, your cost to travel 54 miles is 54/25*6.3*.125 = $1.70 or about 57% of using gas. And, it's more fun.
That's a problem, you only "fill" the Prime's battery up to about 6.6 KWh. So the math comes out: Electric Mode: Cost to fill up for 25 miles: 12.5 x 6.6 = $0.825 Cost for 1 mile = .033 Cost to travel 54 miles: (.825 x 2) +.033 = $1.683 So a little over half the cost. at 12.5 cents KWh.
I'm seeing 6.4kWh to fully recharge the battery closer to standard day temperatures. At temperatures under 50F (10C) there is some rolloff in EV performance but some of that is the lower tire pressure, increased rolling resistance, and denser air, higher aerodynamic drag. My metrics are close to the EPA numbers: 2017 Toyota Prius Prime 25 kWh/100mi - EV for 25 miles (25 kWh/(25mi/100mi)) = 6.25kWh 1.9 gal/100mi - gas So using Huntsville Alabama rates: $0.10/kWh $2.30/gal regular The cost for 100 miles: $2.50 EV = $0.10/kWh * 25kWh $4.37 gas = $2.30/gal * 1.9gal Bob Wilson
regarding the the thread title, i have saved 280 gallons of gas, over almost 6 years, and 57,000 miles.
Not to mention in my area there are a number (most in fact) of public chargers that are free of charge. That helps the math too!
The best I can figure, I'm paying approximately 2.2 cents per EV mile, vs approximately 4 cents per mile on gas.
Yes, but you're driving on infrastructure paid for mostly by the taxes other drivers pay on the purchase of gasoline and diesel fuel. Right now, with EVs making up such a small fraction of the total number of vehicles in use, this implicit subsidy is not a big problem and also promotes a social and environmental good. However, over the long term, just like the various tax rebates and incentives, this situation cannot last. It will be interesting to see how public policy evolves: tax per mile driven, per kwh consumed, or some other measure. Only time and politics will tell.
Thankfully, here in KY, electricity rates are ~$0.063650 (off-peak hours) Super cheap. I have an excel file that you can input local gas cost, and cost per kWh It tells me that it costs me $0.42 to travel the ~28 miles on EV only where as with gas, it would cost me $1.36 to travel that same distance.
The answer to the thread title is yes, you save gas on electricity only. Whether or not you save money by using the electricity is a different question, off-topic to the thread. This answer varies widely depending on weather conditions and electric rates.
I am lucky i work 24 miles one way to work and I can plug it in here at no cost to me. So far 1078 miles on my car avg. MPG 191.8 and still have over a 1/2 tank of gas. Its been a cold month and a couple times the car would not go into EV mode (-27f)
I do hope this is an open book test! And however we figure it, I am killing the MPG I was getting on my commute with my 4WD Tundra---12 MPG!
I have a free charger at work and my commute is 5 miles one way. This was a huge turn around when I had 100 mile a day round trip when I 1st got the Prius prime
I installed PV (Solar) for my home and *EVs EV miles are about 0.5 cents a mile EV is nice EV+PV is awwwwesome
