ChuckJ Posted January 5, 2014 at 01:52 PM Report Share Posted January 5, 2014 at 01:52 PM Kim:One thing that I believe is misleading in the Energi is the MPGe. For engineers, it's technically correct but for users it provides misleading, understated results. What's important to many of us, and what caused us to buy the Energi is saving money on gas. And many people think hybrids and electric cars can't pay for themselves in a reasonable period of time. Right now my MPGe says that I have 58.5 MPGe for the 5000 miles I've owned the car but really it's much better than that from a cost standpoint. We all pay different rates for the electricity. For us, we pay $.09 per kwh. If it takes 7 kwh to fill up the battery and get 21 miles it cost about $.75 for the 21 miles. If I get 42 mpg for a gallon of gas it cost me $1.6 for the 21 miles or more than double. I propose, therefore to have a mod to the software to allow users to use MPGc (miles per gallon based on a cost basis) where you enter the average cost of gas in your area and the average cost of electricity and the car gives you MPGc if you choose to use this criteria. This would give people a more accurate comparison of gas cost to electricity cost of driving. ChuckJ Quote Link to comment Share on other sites More sharing options...
larryh Posted January 5, 2014 at 02:56 PM Report Share Posted January 5, 2014 at 02:56 PM (edited) The MPGe reported by the car is not computed correctly. It is based upon the energy extracted from the HVB. The correct way to compute MPGe is to use the energy drawn from the wall outlet to charge the HVB. The HVB is not 100% efficient. You can't extract all the energy that was put into it. After depleting the HVB, the car generally reports about 5.7 kWh of electricity was used to power the car. However, it required about 7 kWh of electricity from the wall outlet to charge the HVB. So the MPGe reported by the car is about 7 / 5.7 = 1.23 times the true value. In addition, the MPGe reported by the car does not take into account any electricity used for preconditioning. The car would need to track the amount of plug-in energy that was drawn from the wall outlet to provide accurate MPGe or cost information. Edited January 5, 2014 at 02:57 PM by larryh Quote Link to comment Share on other sites More sharing options...
tseibel76 Posted January 5, 2014 at 05:38 PM Report Share Posted January 5, 2014 at 05:38 PM The MPGe reported by the car is not computed correctly. It is based upon the energy extracted from the HVB. The correct way to compute MPGe is to use the energy drawn from the wall outlet to charge the HVB. The HVB is not 100% efficient. You can't extract all the energy that was put into it. After depleting the HVB, the car generally reports about 5.7 kWh of electricity was used to power the car. However, it required about 7 kWh of electricity from the wall outlet to charge the HVB. So the MPGe reported by the car is about 7 / 5.7 = 1.23 times the true value. In addition, the MPGe reported by the car does not take into account any electricity used for preconditioning. The car would need to track the amount of plug-in energy that was drawn from the wall outlet to provide accurate MPGe or cost information. Not to mention this is fairly easy to calculate yourself with a Kill-a-Watt or other similar device. You can usually input all of your information into these devices and they will spit out a cost for you. However, the only way to actually know how much you saved would have been to drive the "other" vehicle on the exact same routes, on the exact same days, in the exact same way, in the exact same conditions (i.e., impossible). We can only estimate. Quote Link to comment Share on other sites More sharing options...
ChuckJ Posted January 7, 2014 at 04:52 PM Author Report Share Posted January 7, 2014 at 04:52 PM Larry: I recognize the inefficiency and think that should be included.Tseibel76: Where can we get a 50 amp, 220 volt Kill-a-watt for our 220v chargers? Kim: Can you address whether it's possible to include the efficiency of specific chargers to include in this option? ChuckJ Quote Link to comment Share on other sites More sharing options...
murphy Posted January 7, 2014 at 05:29 PM Report Share Posted January 7, 2014 at 05:29 PM Where can we get a 50 amp, 220 volt Kill-a-watt for our 220v chargers? I doubt that you will find a kill-a-watt for 220 volts in the USA. It might be available in Europe. I use this meter: http://www.ekmmetering.com/ekm-metering-products/electric-meters-kwh-meters/basic-kwh-meter-100a-120-240-volt-3-wire-60hz-ekm-25ids.html?gclid=CIykm4jK7LsCFW3xOgodKHQA0g to measure the power drawn by the charger. Quote Link to comment Share on other sites More sharing options...
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