Gasoline efficiency

America is a lot more metric than many of us think, runners in the US are quite accustomed to running 5K and 10K races. If a 20K race comes up, most of them will think “ok, that’s twice as far as a 10K run”.
Ball bearings have metric dimensions even in old American made machinery, the exeption being Timkin style tapered roller bearings which are made 1/8 inch increments.
We all buy our whiskey in 500 ml, 750 ml, and 1 liter bottles today, even though some of us are still in the habit of calling a 750 ml bottle a ‘fifth’.

On the other hand, 12, 20, and 28 gauge shotguns are still used in Europe, although they may have given them metric names.
Roller chains are built to inch dimensions, even in Europe and Japan. A #530 roller chain on a new Ducati or Yamaha has a 5/8 inch pitch and a 3/8 inch width.

If someone gave you two GPS coordinates in degrees and minutes and you had to calculate how far apart those points were, what is the most logical distance unit to use? The nautical mile because it is one minute of angle around the earth by definition. That’s why ships captains the world over still navigate in nautical miles. The unit is simply the most logical one to use for that purpose.

I taught math for nearly 40 years and found that when immersed in the metric system, like any new language, people readily adjust. The reluctance has always been political and the temporary cost of conversion and lack of farsightedness that has kept we and Yemen for many years out of the metric logic.

I agree with BLE and feel the best unit measures are this most appropriate to the task at hand. The one saving grace of outsourcing is that metrics are used to make many products more efficiently and with closer tolerances.

The reluctance to convert is the same reason used to change with most people; fear. In this case it is completely unfounded.

My first major project many years ago was to replace the siding, the roof and all the doors and windows in my house using the metric system. Even though not a carpenter by trade, friends in the business were impressed by the work aided by simply using this system. Transference of information and measurement along with closer tolerances makes it a no brainer.

Joseph, that’s true, but I’m not talking about a huge equipment investment, and I’m not producing product to others’ design drawings in my garage.

I spent 23 years in manufacturing, much of it DOD, and evaluated the cost and impact of such a conversion. Much of industry has converted over the years, such as those providing product to the automotive industry, but for much of industry it’s simply not cost effective and can even impact the ability to provide to their customer base. One can convert drawings in inches to metric measurements, but tolerances or costs have to suffer when converting, and the DOD MIL-STD-480 Configuration Control requirements and other requirements make converting extremely expensive. If a jet engine has been qualified to a specific configuration of a design package, one cannot simply convert the dimensions. One would need to do an entire new design package, requalify the product, revalidate the manufacturing documentation package, and then…MAYBE then, it’d be acceptable without testing on the aircraft…
You’re talking millions upon millions of dollars. And the feds are NOT going to pay for the millions you’ll need to spend on new equipment and machinery. Or on the cost of the new design and manufacturing package.

And the advantage to having spent all those millions would be…zero. The engines work perfectly well with everything remaining in inches.

International trade is in bushels and barrels, and much of the manufacturing industry is still in inches, for a reason. It works for the application. Metric is more logical, but there’s nothing inherantly inferior about inches. They work. They’ve worked for centuries. Which is better is largely a function of the industry being supplied.

I believe the biggest obstacle to the metric system in this country starts in grade school. The first introduction to the metric system involves all the inch/metric conversion formulas and the associated math. This really turns the kids off to the system.

Forget the conversions, take them out of the textbooks. Just let the kids use the correct measuring devices in the first place and limit the conversions to the Milli-kilo-deci etc. Given a choice, the kids will gravitate to the metric system because it is so much easier to use.

Another block to the metric system is our government. If our government really wanted us to switch to the metric system, then road signs would be in kilometers, speed limits in kph and all government procurements would specify the use of the metric system for all new contracts. Existing hardware would not require a changeover.

With so much business going global, even our military procurements are multi-national, we really need to take the necessary steps to go metric. The jet engine may not run better, but if you are the mechanic, it would be nice to be able to use the same socket and wrench set on all its parts instead of metric on the parts sourced from abroad and SAE on homegrown parts.

“International trade is in bushels and barrels”

Bushels? Domestically, yes, but internationally?

Caddyman said:

Canada’s tough…They sell gas by the “Imperial Gallon” which I think is 4 liters…

Canada switched to selling gasoline by the litre in 1978. You can go to

and get the price for gasoline at any station in Canada in cents per litre.

piter_devries: “International trade is in bushels and barrels”

“Bushels? Domestically, yes, but internationally?”

Oil is priced on in the commodities market in USD per barrel, but it is actually sold and measured out in tonnes. 1 t = 1000 kg

Bushels is strictly an internal US unit, everyone else uses tonnes. The US also uses tonnes when exporting.

MikeInNH said:

“Stick with one system. There is no need for conversion. It’s just much easier to either stick with SAE or Metric. Many many years ago one of my college physics classes this fellow student was having the hardest time doing some of the simplest problems. What his problem was…if the problem was in Metric…he would first convert everything to SAE then do the problem and then convert back to Metric.o SAE… He couldn’t believe how easy it was to just leave the problem in Metric and do the math…Metric system is a LOT easier to do math problems in since everything is in factors of 10.”

This entire comment makes no sense. Metric (SI) is a system of measurement, SAE is an acronym for the Society of Automotive Engineers which also uses SI as the primary standard in all of its documents.

If you live in the US, then the system is called USC (United States Customary), and if you live in England it is Imperial. However, there are huge differences between USC and Imperial. They are not mutually equatable.

Ametrika - Get a life will ya…Yes in the fantasy world you live in…SAE is the Society of Automotive Engineers…GREAT…we all know that…But it’s also used to depict a measuring system used in the US (inches, feet, yards…miles)…

You’re NOT impressing anyone…

the same mountainbike said:

Joseph, while I agree that the metric system is more logical, the barrier to conversion is the enormous amounts of money it would cost to convert the machinery, tooling, design documentation, manufacturing documentation, and standards in the manufacturing industry.

There are minimal one-time costs and huge profits to be made when a company shuts its domestic doors and reopens in a metric country with all new modern metric tools, metric skilled workers, new metric designs and updated metric documentation to modern ISO metric standards.

The old stuff left behind is either sold off as scrap or left to rot.

The barrier to metrication is a lazy and arrogant population who refuses move forward with the times.

BLE said:

“It’s not that Americans are anti-metric, it’s just that many of our points of reference are in English units and if you tell me that your car uses 8 liters of fuel per 100 km, I have no idea if that is good gas mileage or mediocre gas mileage without converting it into mpg first.”

So are you telling us you are incapable of learning how much fuel you are using when you use 8 L/100 km.

Consider this: You have a full tank of fuel and your tank just happens to hold 80 L. If you burn on an average of 8 L/100 km, then you can go 1000 km before refueling. If your average driving is 50 km/day, you can go 20 days on a tank of fuel.

A person of average intelligence should be able to get a feel for it after two fill-ups.

No wonder America is in decline.

Ametrika, I’ll be blunt; I resent being called lazy and arrogant. I reserve the terms “lazy and arrogant” for those who resort to name calling in a debate.

There are many of us here who disagree on the issue of metrification and discuss its merits and costs as we each understand them in context with our own education and experience. But we do so in a respectful manner. Name calling does not earn you respect.

Your comments calling otheres lazy, arrogant, incapable “of learning how much fuel you are using”, and implying that those who disagree with you are not of average intelligence, are not welcome. And comments disparaging America do not help.

Please feel welcome to join the debate if you do so with respect for others. Please don’t if you cannot do so. I, for one, am getting tired of reading such comments.

Mike in NH said: "Ametrika - Get a life will ya…Yes in the fantasy world you live in…SAE is the Society of Automotive Engineers…GREAT…we all know that…But it’s also used to depict a measuring system used in the US (inches, feet, yards…miles)…

You’re NOT impressing anyone… "

Such a comment coming from a guy who responds to my comment in less than 10 min.

Sorry, sir but in the real world SAE is the Society of Automotive Engineers, like it or not, and if you were a member of their group you wouldn’t be making such obvious blunders. It isn’t used anywhere in the US to mean a measuring system. I checked both the SAE International web site and Wikipedia and there is no mention of SAE meaning a measurement system. You you are propagating an error.

I don’t need to impress anyone, just to correct obvious errors.

Is our old “friend”, piter devries/tarcaulk, posting under a new name, or are we now confronted with yet another hostile person who wishes to dominate the board by contradicting and criticizing other, long-term, respected, members of the board?

Ametrika–This is not the way that we roll on this board.
Get with the program if you wish to continue to be able to post on this board.

I think liters per 100km is a better measure than MPG, and I think (quantity of fuel)/(distance travelled)–generally–is a better measure than (distance travelled)/(qty. fuel burned).

For instance, say you improve the fuel burn of a largish truck from 10 to 11 MPG. Big deal, that’s only one MPG, right? Then lets say you improve the fuel burn of a hybrid from 50 to 55 MPG–5 whole MPGs!

So you’d expect the +5MPG to represent 5 times bigger savings. (Or, if you’re really sly, you’d realize both gains are +10%, so you’d expect similar fuel savings).

As it turns out, over a 1000-mile trip, the 55MPG car saves 1.8 gallons over the 50MPG car…but the 11MPG truck saves 9 gallons over the 10 MPG truck!

Since we generally want to know “how much fuel does it take to complete a trip?” Putting distnace in the denominator makes for a more easily used measurement.

. It isn’t used anywhere in the US to mean a measuring system.

And you’d be WRONG…But I’m sure you are used to that.

You’re still NOT impressing anyone…Maybe except yourself.

“It isn’t used anywhere in the US to mean a measuring system.”

I’m sure that SAE doesn’t intend SAE to stand for a measuring system, but through common usage it has come to mean that to a lot of people.

When someone uses the term SAE when they mean inch system or whatever, I know what they mean, even if it isn’t technically correct. I don’t find the need to correct everyone on that either. Got better things to do.

To Bruce W. about gas mileage. I live in Canada & have no problem with miles per. gallon even though it is all in litres here. Example take on 45.9 litres divide that by 4.546 which is number of litres in our gallon, would =10.09 gallons. Now if I travel 420.1 KM,s Take 420.1 KM,s times .62 will be 260.4 miles. Then divide 260.4 miles by 10.09 gallons will be 25.8 miles per. gallon. Very easy I have kept records for years like that since our crazy Gov,t switched to metric. hope this helps.
I always keep a calculator in my vehicle then you can get the figures very close.
Honda Bill

Hmmm. When I go get a sheet of plywood I want it 4x8 feet and 3/4 inches thick. I want my ceilings to be 8 ft high. I don’t want a 1x2 meter piece of plywood. Sheesh, if we switch to metric, next thing you know we’ll have to switch our house wiring to 250v DC with those big ugly plugs and switches. Then we’ll have to have a king and queen and spell center centre and tire tyre. No thanks. While conversions are easier without a calculator, who doesn’t have a calculator? I just think its a big non issue.

meanjoe75fan wrote: " I think liters per 100km is a better measure than MPG, and I think (quantity of fuel)/(distance travelled)–generally–is a better measure than (distance travelled)/(qty. fuel burned).

For instance, say you improve the fuel burn of a largish truck from 10 to 11 MPG. Big deal, that’s only one MPG, right? Then lets say you improve the fuel burn of a hybrid from 50 to 55 MPG–5 whole MPGs!

So you’d expect the +5MPG to represent 5 times bigger savings. (Or, if you’re really sly, you’d realize both gains are +10%, so you’d expect similar fuel savings).

As it turns out, over a 1000-mile trip, the 55MPG car saves 1.8 gallons over the 50MPG car…but the 11MPG truck saves 9 gallons over the 10 MPG truck!

Since we generally want to know “how much fuel does it take to complete a trip?” Putting distnace in the denominator makes for a more easily used measurement."

That is correct but the same principle applies to the time saved by high speeds.
For example, if you have a two mile commute to work and the first mile is a neighborhood with a 15 mph speed limit and the second mile is a highway with a 60 mph speed limit, what saves you more time?, going 120 mph for the second mile or going 20 mph through the neighborhood?
Going 120 mph on the highway turns a one minute mile into a 30 second mile and saves you 30 seconds of time.
Going 20 mph in the 15 mph zone turns a 4 minute mile into a 3 minute mile and saves you a whole minute of time. This fact is not intuative to most people which is why you see people going 80 and 90 mph on the freeway yet you almost never see anyone running to their parked cars as fast as they can run.

I think we should measure speeds and post speed limits in seconds per mile instead of miles per hour.