Norm, A few observations, if I may. It would probably be most persuasive and clear to have a narrower scope in what you send in letters to the editor. Your letter was about the imprecise and unnecessary conversion to miles. The parts describing grams, liters, prefixes, pronunciation, and weight vs. mass are confusing because they are not backing up the main point. They are intended to be a mini-tutorial, but distract from what you are trying to say.
In the first sentence, you try to make different two points (the inaccuracy of the conversion and "6.2 miles which is a measure becoming obsolete..."). It took me a moment to parse the sentence. 150 words is just not enough to do more than carefully lay out an argument and explain your reasoning. Always give clear context, make it very clear what your specific purpose in writing is, and explain how you came to that conclusion. "In yesterday's paper you mentioned the annual 10 kilometer race, which you called a 6.2 mile race. Actually, 6.2 miles is 22.067 meters (72.399 feet) too short! Let's give the runners credit for all of the distance they run. It is a ten kilometer race, so just call it that. There is no need to convert it into miles, and it isn't accurate." Carl
