All cars should records MPG stats and upload..

[jmra]

Maybe it's just me but our vehicles have always been pretty close to the sticker (maybe a mile or two less but the wife and I both have a heavy foot).
Our last three have been real close including a 2005 XB (sticker said 32 - wife would get 30 but would hit 75-80mph on the way to work every morning), 2012 Tundra 5.7L (right on with sticker), and a 2012 Highlander 3.5L 4x4 (just under sticker but again the wife is driving).
Seems to me the worst offending cars on mileage claims are the hybrids. Heard a lot of people are not getting anywhere near sticker claims. Maybe they have worked out the issues but from articles I read several months ago a large percentage of hybrid owners do not end up being repeat customers.

[JALLEN]

The claimed mileage is for a given set of conditions. Most consumers aren't duplicating that.

This is one of the paradoxical effects of competition. Nobody paid much attention to great mileage back in the '50's. You bragged on your car because it was so large, so comfortable, so solid. Why worry about mileage, since gas was only .129 per gallon or so for regular, and you got full service, green or gold stamps, a glass or other premium, your windshields washed, your tires checked etc.

Once the price of gasoline started to increase, some manufacturer got the idea to sell cars based on getting better mileage than the other cars. Exaggeration and out right misrepresentation became necessary, customary, and pretty soon, complaints invited regulation. A more recent phenomena has been the mortgage companies competing on the basis of interest rates. Only the most naive do not realize there are more ways to play interest rate claims than a piano, but now that has been regulated into APR. Since it was important, cheating became tempting, and now the calculation is prescribed to such detail as to be almost incomprehensible.

I keep track of the mileage each tank on my cars. The figures vary from week to week, sometimes depending on the highway vs. surface miles driven on each tank, sometimes not. They vary depending on whether my wife drives which car and how much. She gets better mileage than I do.

Generally, having all the info hasn't helped, either making decisions on which car to own, or which gasoline to buy. Even that is fraught with uncertainties.

[ryouiki]

Hmm,

I'm not really sure what you are looking for here... putting aside the privacy concerns, simple calculated MPG from the vehicle (outside of using a odometer and a pen & paper )? Quite as few cars already calculate and display this (both of my cars calculate rolling average and running count)... those that don't directly display this can usually be captured by using the OBD/II port + data logger:

http://en.wikipedia.org/wiki/On-board_diagnostics

The performance car community has been accessing this type of data for years... along with far more detailed information. Some also modify their ECM/ECU to provide better gas mileage/power, particularly on vehicles that are neutered by trying to meet California Emissions standards.

That said, NHTSA is planning on requiring data recorders (mainly to use in case of accidents, etc.) in 2014... but I suspect once data logging is more widespread, I would not put it past manufacturers to try to game the system.

[i8godzilla]

The last two trucks we purchased did not include a MPG estimate. As someone else said, the were bought because of the intended use. 3/4 and one-ton trucks (and larger) are exempt from this exercise.

Another law will ony add more cost in the end. I want to elect more people that vow to repeal laws not create more. In a free country every law passed takes rights away from someone.