Defining "extremely fuel efficient"
 

I've been running a blog on the Mother Earth News website re my 100mpg sports car, and am attempting to draw a line in the sand. I'm calling cars above the line extremely fuel efficient, and defined it thus in a footnote:

>>*What does “extremely fuel efficient” mean? Let’s define it as double the Corporate Average Fuel Economy standard for passenger cars. MAX gets about triple the CAFÉ standard, so I don’t think I’m setting the bar too high.<<

Using that definition, there are a whole bunch of ecomodders here who have made their cars extremely fuel efficient. The CAFE standard for cars stagnated at 27.5 mpg for 20 years (from 1990 to 2010) and this year bumped up to 30.2; anyway, I'm wondering if CAFE x 2 (slightly over 60 mpg) is a practical goal (a goal we should be asking conventional auto manufacturers to aspire to) but I'm also wondering if it's too easy a goal to deserve the adjective "extremely."

I'm prepared to change both the terminology and the definition if anybody has a better way to phrase it...it seems a bit clumsy to me but it's the best I've come up with. Your advice will be appreciated.

I wonder how a vehicle's utilization of it's cargo capacity could be included? For example semis and busses are down in the single digits mpg wise, but are far more efficient re: units of stuff moved per unit of fuel.

Note how I said UTILIZATION of capacity, as we all know (if we are willing to admit it) that the Suburbans and Expeditions of this country see more solo occupant duty than anything else.

Very good point Frank..

I also feel that "very fuel efficient" should be applied per car class..

e.g. 70+mpg Sub compact
60+ mpg compact
50+mpg Mid size etc

I think there is merit in approaching a mover to beter fuel efficiency in 2 stages

1. Get everyone moved to the most fuel efficient version of the car they THINK they need
2. work on shifting people to more appropriate transportation options

For small cars - around the 3,5m to 3,8m / 12'-13' mark - extremely efficient would well above 80 mpg US / way under 3L/100km in metric , as that's what possible right now (NEDC) with commercially produced highly efficient vehicles.

60 mpg is definitely too easy, since I've averaged over 71 mpg for the 100K miles I've driven my 2000 Insight.

Yes. Let's imagine a family with but one vehicle. It may need to carry all of them when the decision is reached to use it. For pickups it becomes even more complicated due to towing and payload capacities.

Personal transportation should be separated from vehicles chosen for specific work capacity (that double as personal transportation at times).

The bar needs to be set rather high in re trailer and load weight as many cars can tow a good deal more than Detroit would try to lead us to believe, thus a car w/trailer trumps most situations where a pickup appears to be a default choice.

Off the top of my head I would choose 1,000-lbs of freight, and/or a 5,000-lb trailer load for distinguishing between the "biggest" car for towing/carrying maximum numbers (this includes minivans) and the point where a truck is a somewhat better choice.

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In my family this would ultimately guarantee that we would have a large truck to do all the work, where a practical single vehicle would lean more toward a fuel efficient minivan. In my case we have to tow a 9,000lbs tractor about 4 times a year for a 700 mile round trip. A minivan can't do that no matter how it's built and still maintain it's fuel efficiency. So, we have multiple vehicles and basically keep the truck parked next to the tractor for when they are needed.

On another note, to answer the question at hand. My personal view of an extremely fuel efficient vehicle would be one that creates a smaller demand on the environment and leaves a smaller carbon footprint. For example I'm not a fan of battery powered vehicles or hybrids because of the toxins used to create multiple battery replacements over the expected life of the vehicle. In my mind a 40mpg straight gas vehicle has a smaller carbon footprint than it's 50mpg hybrid counterparts; after you factor in everything that it actually uses to get there. At what point do the mpg's outweigh the replacement of toxic batteries and all the waste created to replace those batteries? (not to mention the actual energy source needs to be factored in -ie: nuclear, coal, wind...).

Another way to look at it is diesel engines can create a lower carbon footprint by not only being more fuel efficient but by using less refined fuel. The carbon saved in the refining process should be factored into the carbon savings for a diesel engine.

In conclusion Instead of rating vehicles on mpgs we should be rating them on their overall carbon footprint from the actual origins of each car (imported from x country= +carbon footprint of shipping), how it's manufactured to it's power plant and it's energy source. How that car fairs across a 15-25 year lifespan and the overall carbon footprint it will create in its lifetime. We should look at actual numbers over not just one owner but all owners for the life of each vehicle (15-25 years?). Because that vehicle will continue to hurt or help us after just the initial purchaser has passed it along.

Being short sided is not going to solve any problems we have to look at the whole picture from birth to death and everything in between. How are they manufactured, what carbon footprint will be created in it's wake while in operation, how are they maintained, how will they be recycled?

IMO this title should be changed to "Extremely carbon efficient".

I personally don't think there is much point to creating those type of labels. I quite often hear people complain because they can't achieve the EPA estimated mileage (and it it almost always due to driving habits); however, these forums are proof that most people can quite easily increase their EPA estimated mileage by 20-30% just with driving habits. Regardless of what you want to list as "extremely efficient," people are going to find a way to sabotage that efficiency, again, making the label moot.

In another blog entry. You make an excellent point. When I'm one of eight passengers in an airport shuttle van I'm experiencing better passenger mileage than I am in MAX. I think fuel efficiency in a community would best be served with a number of vehicles--a bunch of 100+ mpg small capacity vehicles (one or two people, or one person and modest cargo, used for commuter/"grocery getter" tasks) a few Metro-size vehicles, a minivan with removable back seats, and a pickup truck with trailer-pulling power.

I drove from Indiana to Pennsylvania in the company of a guy (George Voll) with an ecomodded (small diesel and streamlining) Metro sedan, it was less than ideal conditions (raining buckets) but we ran one leg at 45 mph (which is about best economy speed for us both), I got 113 mpg and he got 94 mpg.

I'm a childless bachelor in rural Oregon, 4 miles from a small town but 30 miles from a big one and I have a weekly business trip to a city 170 miles and I'm usually driving solo and lightly loaded, so for my lifestyle my 20% better mileage overall equals 20% better passenger miles.

George is a family man in rural Indiana and lives 15 miles from town, he has a wife and two kids and his car is his daily driver, running the kids to school every morning etc etc so for his lifestyle, his car is way more fuel-frugal than mine. I'd say George averages 2 passengers (including himself) aboard, so even if I dock him a bit for the extra weight he still has me beat by 60% per passenger mile.

Gosh, I've hijacked (no relation) my own thread, but Frank made such a good point I had to follow up on it: if we're going to give mileage credits for cargo capacity, utilized capacity is what matters. If you're commuting to work in an Escalade, you don't get extra points because you COULD be hauling a basketball team and a boat trailer.