This is in response to Bob's thread below from diesel thread. I believe this deserves a separate thread. First of all: no I am not doubting EPA estimates or calculator accuracy. What I am questioning is the defaults used for calculations. By default annual mileage is set up to 15,000mi with 55% city driving. This gives 8,250mi annual in city, or if car used 5 times a week/total 250 days a year, 33mi a day. Is it really realistic to assume that the majority of the people drive 33mi a day in the city?? For example, average commute time in LA is 28.6min. Driving 33mi even at whooping 14mph would take 2h20min Ten cities with the worst traffic
This is a chart generated from ZVW30 owners in the first year: This chart predates all but home-grown, plug-ins and is the closest I have to daily mileage of ZVW30 owners but it gives us some owner pattern clues: Daily distances shorter than 50% of an EV range, ~80 miles would give ~40 miles, this is where the EV is supreme for cost per mile. Daily distances longer than ~40 miles are in the hybrid sweet mode. Daily distances around ~120 miles are in the speed range where a diesel-style driving approaches the Prius. Any distance under are going to be a clear win for the Prius. Now if we use the 'way-back' machine and look at the CNW Marketing 'report', it turns out that under ~7,000 miles per year, it doesn't matter. The operational costs are so much smaller than purchase, licensing, and insurance, one might as well get that Hummer or tank-like car. We had a 2001 Echo and over 9 years, put only 30,000 miles, less than 3,000 miles per year. A Prius is not always the best choice because none of us have exactly the same requirements. In our case, I'm 65 years old and my wife is older. We'll soon enough graduate to 'fixed income' so operational costs become more important. For us, an EV or plug-in makes sense but we have two Prius, paid-for. And, I know how to drive them efficiently. So the last years of employment, I'm fixing the house to be more efficient and then other projects. Bob Wilson
The 55:45 city:highway split isn't representative, and the EPA knows this. In surveys it has conducted, people identified their split as 43:57, and that is close to what the EPA uses in their MOVES program. I posted this awhile back here, Diesel mpg underrated on the window sticker | PriusChat The city and highway cycles that form the core of their emission and fuel economy testing have not changed since they were developed in the '50s. People that drive in the center of big cities, or in bad rush hour traffic, regularly may drive a cycle close to the EPA's city one. For everybody else out in the suburbs, their 'city' driving is closer to the EPA's highway cycle.
What I mean that EPA combined MPG is as deceitful as hwy MPG used by some advertising. The fact that it is slanded towards hybrids and BEV is a minor part, the biggest issue it doesn't represent any realistic scenario. I would argue that we have 3 cycles: city, highway and extra-urban (I think Brits use this breakdown), and it is not realistic to expect more 5-10mi/day of pure city driving; some in 1000-3500 annual. Most of my driving falls into extra-urban category, with average speed ~35mph.
There are 5 cycles, 4 of them represent how people drove in 1940s LA. City, and highway are the old tests, they added air conditioning and cold weather using the same driving profiles and high speed. Only the high speed (US06) portion represents how americans drive in modern cars. Only the old city and highway are used for cafe purposes. Detailed Test Information As mentioned earlier on the thread, somehow the epa comes close, but these are not realistic tests. West virginia university tried to actually drive in modern driving cycles (that's how they caught VW without intending to do it). I'm sure a better test could be made, but the car companies like the current format. They have spent years optimizing their cars to pass these tests. That is a great reason to change them The epa 5 cycle test appears much better than the european NEDC or Japanese JC08 which have even deeper flaws.
Guys. I don't think it's efficient to drive a BEV anymore unless you find the free plugin stations. Driving a prius or prius plugin (which gives you the choice) is more efficient and cost effective. The 4th Gen will be widening that gap too. Tesla doesn't even tout savings per mile anymore. I think on average people are saving like 4 cents per mile driving a prius vs BEV...
Why retain current cycles? Consistancy. To plan future CAFE goals while changing the CAFE tests puts manufacturers in an impossoble position. The Prius gets flak for being slow but when these tests were written lots of cars had less than 70 HP. (I owned 5 of them) So modern drivers expect both faster and quicker cars.
average per capita vmt is about 10,000 miles, being skewed down by students and the retired. That is if averaged daily 15 miles in the city with a 55% split. Not bad assumption if you are trying to guess pollution in LA in the 1940s. I absolutely agree that for the average commuter 55% city is simply wrong, but the whole test is wrong. The city highway split is wrong too, but that is probably there for historical reasons. Still with the bad politics making it so you can't fix the test, epa still did better in 2008 revision than the europeans and japanese with even more unrealistic tests.
...this could be a separate thread, but CARB states especially Ca. are generally adding taxes to gaso and giving credits to EV and electric use. Ca. has said they will do whatever it takes to make EV succeed. So be careful many a technical argument has been lost not accounting for gov't policy
