Add a Comment
Email This
Statistics
RE: legislation is not always the answer
part of the problems associated with making engines fuel-economical is that the EPA continuously changes the rules for compliance.
Completely agreed. There was an article I read on-line (which I can no longer find) three years ago when I was learning about OBD that detailed the stagnation of fuel efficiency because of environmental concerns. There was a distinct period in the 90s where vehicles were less efficient than their 70s and 80s counterparts because the movement to reduce smog and noxious emissions was overrode all else. Playing to environmentalism is an easier banner for a politicians to wave because it looks good now and failures will come years down the road during another administration's reign. All the while, like you said, American engineers are faced with redesigning to meet the latest specifications.
regarding the speed limit change, i am extremely skeptical of that step. how effective would it be, especially when compared to the cost of the step? ... what is the cost in labor for having people sit in traffic longer and take longer to make their trips? i'd like to think my time is worth spending an extra couple bucks on a trip - at least that's what my employer thinks.
So let's use the speed graph from the Improve MPG: Factors Affecting Fuel Efficiency article. Essentially, the difference between 55mph and 75mph is nearly double the amount of fuel (3.78 units per time vs 6.65 units per time). Now assume you're driving 1000 miles. At 55mph, that will take you 18 hours. At 75mph, that will take you 13 hours. Using the fuel multipliers, 55 mph "costs" 68.72 units of fuel while 75mph "costs" 88.66 units of fuel. So there really is no argument that driving faster saves gas because the engine is running for less time. Running an engine for five extra hours in a more efficient manner uses 23% less fuel!!
To your point, though, time is money and money drives business. So the application of this question is whether or not getting to your destination is worth it. For shipping and transportation? A business saves money in overhead (and can do the Wal-Mart thing and make "we're green, buy our stuff" commercials). For personal commuting to work? Your commute needs to be at least 37.5 miles for driving 75mph to save you 10 minutes over driving 55mph. Is 10 minutes worth a Middle Eastern oil dependence? Do you really want to get to work faster?
... perhaps the gov't ought to outlaw off-road vehicles, like jeeps, with their non-aerodynamic light bars and canoes. =)
I realize, of course, this was said in good humor but it's a statement that many have made before. For a white collar world, such a measure isn't entirely off base. But America does make good use of its pick-up trucks and specialty vehicles, a role not well filled by a Prius, Yarus or equally-ugly-&-small-us. As far as SUV's go ... almost none of them serve any purpose that could not be equally served by a mini-van. An off-road 4x4 [Land Rover / Jeep Wrangler] do differentiate themselves from SUVs (ironically, the New Jersey DMV lists my Wrangler as a station wagon) in their ability to actually negotiate rough terrain. All of this is only relevant when one actually uses their vehicle for such a purpose. Mine has served well in driving me into the wilderness for mountain biking trail heads, remote campgrounds and fording through seriously bad weather whilst other vehicles slog along at 20mph or get stuck. For the record, I use public transportation (buses and subways) for my day-to-day commuting and the Jeep for my recreation.
RSS
legislation is not always the answer
part of the problems associated with making engines fuel-economical is that the EPA continuously changes the rules for compliance. it takes time to engineer in accordance with a standard, and the changes to the rules hurt the businesses. while IANAEE (engine engineer), my dad is one, and this is one of his major gripes.
regarding the speed limit change, i am extremely skeptical of that step. how effective would it be, especially when compared to the cost of the step? speed limits ought to be about safety (which is a completely different topic - i am for the abolishment of our current traffic laws and the institution of the german laws). are there other steps that would better help our short-term consumption of gasoline? how much of our consumption is due to speeding, compared to sitting in traffic or flying? how effective would it be anyway, considering the majority of the population thinks speed limits are too low. there is already an economic incentive to drive with fuel economy in mind - do we want to have our police forces out giving ridiculous tickets as an additional incentive? and what is the cost in labor for having people sit in traffic longer and take longer to make their trips? i'd like to think my time is worth spending an extra couple bucks on a trip - at least that's what my employer thinks.
incidentally, cruise control and a 55mph limit would probably get worse mileage than someone with a flexible speed in hilly terrain. there's nothing more wasteful than hitting your brakes while going downhill just because john-law is waiting to treat you like a criminal, and then punching it to maintain the speed when going back uphill.
perhaps the gov't ought to outlaw off-road vehicles, like jeeps, with their non-aerodynamic light bars and canoes. =)
View Full Discussion