35MPG CAFE requirement really not all that impressive...

[imzjustplayin]

People hear 35MPG and they think OMG how can any vehicle possibly do that! What they don't realize is that the new CAFE MPG requirement of 35MPG really only means that the entire vehicle fleet in the US for vehicles with a GVWR of 10,000lbs or less is 27MPG. They've actually clarified things further where the minimum is actually 34MPG with 1MPG extra if they can't find improvements in evap emissions or something like that. Also it is said that the requirement basically states cars need to average 39MPG CAFE and trucks 30MPG.. But remember that's CAFE MPG which is much higher than actual MPG.

39MPG CAFE MPG=about 30MPG NEW EPA MPG
30MPG CAFE MPG=about 23MPG NEW EPA MPG

How do I know this? Because if you can go to the EPA website and find the fuel economy information which is stored in excel files for most years and is comma delimited for the older ones (pre approximately 1998 Model Year). You then choose a vehicle, look for its Combined Unadjusted MPG which is the Combined CAFE MPG of that vehicle.. Then in the same row you can find the Combined "Guide" MPG of the same vehicle, except this number is the one that you would see on the fuel economy guide like the monroney sticker or on the fueleconomy.gov website.

For example... The guide "Combined" fuel economy number for the 2010 Prius is 50mpg.. However that same Prius for CAFE purposes is getting 70.894MPG Combined.

So what I did was I found a few vehicles, one that gets a CAFE MPG of 35, 30 and 40 then looked at the guide MPG of each corresponding vehicle. It turns out that a vehicle that gets a 35MPG Combined CAFE, is actually getting in real life around 27MPG combined. A vehicle that gets 40MPG CAFE is 30MPG in real life, and a vehicle with a 30MPG CAFE rating is 23MPG combined in real life..

So really, these CAFE numbers aren't all that impressive and are basically bumping up vehicles to the mileage they should already be getting and not mileage we need them and are certainly capable of getting.


Oh and even worse... The CAFE numbers for the longest time were 20.7MPG for trucks and 27.5MPG for cars... This means that the requirement was 16MPG for trucks and 21MPG for Cars..

[theholycow]

Good work. I've come to the same conclusion from seeing the same data as well as reading a few articles, but I never went into that much detail about the actual numbers.