The vehicle size is determined by the "Interior volume index" (in cubic feet). A compact car has between 100 and 109.9 cubic feet, and a mid-size car has between 110 and 119.9 cubic feet.mwalsh wrote:Nice stuff. One thing that popped right out at me was the classification of the LEAF as a mid-size and the Volt as a compact. Not that I think it makes any difference, but what is up with that anyway?
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City Highway Combined Actual: 39 48 Old: 38 47 42 New: 32 42 36
AndyH wrote: I don't like the revised EPA numbers though. While the new 70% number better reflects the 'economy' of a typical American car being driven by a typical driver and their jackrabbit starts to 10mph over the speed limit with the AC blasting, I find that the old EPA number very accurately mirrors the economy from a reasonably conscious driver.
Except that 73 miles appears to be fairly representative of the range that you'll have if you drive on the highway at 70mph with the AC running on a warm day... I know that in my Prius in those conditions I get will high 40s to 50 mpg in that scenario. I've only broken 50 mpg a couple times on a whole tank - worst tanks were around 40 mpg but lifetime average is 46 mpg - or just about what the EPA says we'll get.AndyH wrote:While it's unfortunate that the EPA takes the Leaf down to 73 miles range, I think that folks transitioning from other EVs or the Prius (or are reasonably conscious drivers) will get much closer to Nissan's reported 111 city miles and 94-97 miles highway.
But that is not what EPA is saying it is. EPA says it is a "combined" city/highway cycle - with some use of AC/heater.drees wrote:Except that 73 miles appears to be fairly representative of the range that you'll have if you drive on the highway at 70mph with the AC running on a warm day...
1. Electric Vehicle Test Procedure - In general, EPA testing follows SAE Recommended Practice
J1634 "Electric Vehicle Energy Consumption and Range Test Procedure," which (as the title implies) is
basically a dynamometer test procedure used to measure the energy consumption and driving range of
an electric vehicle.
Electric Vehicle - City Test Procedure Summary - Following SAE J1634 Recommended Practice, the
battery is fully charged, the vehicle is parked over night, and then the following day the vehicle driven
over successive city cycles until the battery becomes discharged (and the vehicle can no longer follow the
city driving cycle). After running the successive city cycles, the battery is recharged from a normal AC
source and the energy consumption of the vehicle is determined (in kW-hr/mile or kW-hr/100 miles) by
dividing the kilowatt-hours of energy to recharge the battery by the miles traveled by the vehicle. To
calculate the energy consumption in units of mpge (miles/gallon equivalent) we use a conversion factor of
33.7 kilowatt-hours of electricity per gallon of gasoline (which is basically a measure of the energy in
gasoline (in BTUs) converted to electricity). The city driving range is determined from the number of miles
driven over the city cycle until the vehicle can no longer keep up with the driving cycle.
Electric Vehicle – Highway Test Procedure Summary - The same test SAE J1634 procedure outlined
above, is used determine the highway energy consumption and the highway driving range (except the
vehicle is operated over successive highway cycles) .
Electric Vehicle - Adjustment Procedure used to Derive City & Highway FE Label (Window Sticker)
Estimates - EPA regulations require the city and highway energy consumption and driving range values
listed on the FE Label (window sticker) to be adjusted to more accurately reflect the energy consumption
and driving range that customers can expect to achieve in the real world. For EVs, EPA currently uses
the derived 5-cycle adjustment method described in 40 CFR 600.210-08(a)(2)(i) and (a)(2(ii), capped at a
maximum adjustment of 30% (i.e. multiply unadjusted values by 0.7).