But fortunately we have google.
http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla:en-US:official&q=8.7 liters/100 km in mpg&btnG=Search or http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla:en-US:official&q=8.7 liters/100 km in miles per uk gallon&btnG=Search

http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=6FZ&q=174 pounds/square inch in kilograms/square meter&btnG=Search

http://www.google.com/search?hl=en&client=firefox-a&rls=org.mozilla:en-US:official&hs=4aE&q=1,6 grams/cubic centimeter in pounds/cubic foot&btnG=Search

You have to realize that all of industrial U. S. uses the English units, and it would be too hard to re-fit and re size all of their existing units. It would even be hard enough to do the same for just new units, because you would still have the problem of conversions when working with the old units. The English system will be used either until it is mandated to use or all industry gets wiped out in the U.S. (and Liberia and Myanmar) and we have to start from scratch.

This is my theory: the right time for adoption passed. A standardized system of measurement was sought, particularly in the European countries, so, for example, everyone was trading in the same quantity of bananas. Inter-Europe trade, as well as engineers rebuilding post-world War 2 Europe made the push for metric. (Which is why England was the last country to make the switch, since they were isolated from the rest of Europe.)

The US was an island all onto itself, so trade wasn't dramatically affected by not using metric. The serious effort to go to metric hit in the late 1960s...but by the early 70's, some of the main proponents of metrification--engineers and other people who use units--became less interested. Why? Calculators. Once every engineer had an HP on their desk, the need for a base 10 universal measurement system became far less and people just didn't have the fire in their belly anymore.

According to my theory, we'll never switch now. It's easier to convert than to standardize.

Use of miles does have advantages on US highways, in that most every major city west of the Mississippi river has their major streets layed out in a grid that is roughly one mile long by one mile long. Making all east/west and north south/interstate exits almost exactly on a mile apart for signage. Converting interstate exits to meters would introduce very odd fractions or inaccurate distances on signs due to 1 mile equaling 1.609 meters.

1 mile = 1.609 Kilometres.

I really understand what he's saying, i just for fun googled 8.7 liters/100 km to mpg. And it gave me the answer of ~27mpg. And then i actually looked for websites that referenced it. Up pops a site about BMW, which says that 8.7 liters/100km is equal to 22.5mpg. Obviously there are problems with conversion, And it just makes sense to switch.

The problem here is that the BMW website being a European Company will be referencing Imperial Gallons rather than US Gallons. Not only does the US insist on using the old Imperial System they also arbitarily change the size of the units. The US Gallon is smaller than the actual Imperial Gallon therefore making a gas mileage of 22.5 mpg Imperial equal to ~27 mpg US.

Another sign of the arrogance of the US is that they (and Canada by default) are the only English speaking countries in the world that drive on the right side of the road.

barsoom - This has nothing to do with the original article, but there are actually far more countries in the world that officially drive on the right than on the left - 74 drive on the left, 165 drive on the right. The only reason England doesn't drive on the right is because Napoleon never conquered it and forced it to change from the left-side driving established during the Roman Empire, to right-side driving which was the standard in France and which he forced all the other European countries he conquered to use.

So much for the American "arrogance" theory - I think the most obvious answer to the question in the article has been posted above. The US is full of manufacturing facilities that all have machines with the old measurements - and when you replace an old very expensive machine with a new very expensive machine, you're unlikely to change the metrics used because that would force a change to all the other very expensive machines used in your manufacturing process.

There was a metric board commissioned by Congress that ran through the Carter administration and was killed by Regain.
From the looks of it it was mandated under the Ford Admin without teeth and from the looks of it "made to fail" from before the very start.
Here's a summery:

http://lamar.colostate.edu/~hillger/laws/usmb.html

I first heard that the USA will be converting in 1975. The most noticeable sign was gasoline sold by the liter, which caused great confusion. About the same time, McDonald's had McMetric rulers, which got me hooked on the metric system. I was 8 years old then. Vanity might be another issue, with body measurements posing an interesting situation. It would be natural to choose the unit that would give the most flattering number. If there is pressure to make a body part larger, we might use the smaller unit, the centimeter. If the pressure is for a given part to be smaller, we might use the larger unit, the inch. Although there is much pressure to lose weight, the USA still uses pounds, although kilograms might produce a more flattering number.

I really can't tolerate the imperial system ,it seems irrational when compared to metric. Hasn't the imperial system caused confusion and failures such as the early faults with the Hubble space telescope.One thing that really gets my goat is the American use of the fahrenheit scale rather than the rational celsius.In celsius, water freezes at 0 degrees and boils at 100, while fahrenheit seems plainly insane. I can't see how there would be much difficulty with adopting celsius,it could be done overnight.There seems to be some sort of bizaare conservatism at work.

You forgot to mention in your article that in many areas the US uses the metric system. Military, one of the biggest manufacturing industries. In science, NASA uses the metric system throughout. Famously, the Mars orbiter crash was caused by one contractor supplying non-metric parts and calculations. Whenever the US manufactures a product for external sale it has to create a metric product. Think of a major manufacturing industry and it buys or sells parts from non-US countries. Do you think it is easy for GM to make separate US only components for internal sales?

If they woould just start teaching the metric system at the grade school lvl instead of waiting untill high school were it is already going to be odd to the students

WHY IS THE US SO BACKWARD IN ADOPTING THE METRIC SYSTEM? WE WILL HAVE TO SOON TO COMPETE WITH THE WORLD MARKET.