> Using imperial units is always unfortunate, but when dealing with the typical unit of gasoline in the US, it's inevitable.

Well, no, when dealing with the typical unit of gasoline in the US, Imperial units are irrelevant, and US Customary units are inevitable.

I gave all my numbers making it trivial to check that I am using the us gallon and. Perhaps a site for kids that you cited isn’t using more than one sig fig?

The kids site is far more correct than yours, and consistently uses two significant figures in its calculations. See, for example, the US federally accepted value of 19.59 pounds or 8.887 kg CO2/gallon burned:

https://www.epa.gov/energy/greenhouse-gases-equivalencies-ca...

Your error appears to be using a single significant figure for the density of gasoline, at 700. Other sources place it from 711 to 749 kg/m3.

Hopefully you will reconsider my comment being "not nice," since you started with one sig fig and ended with four, and then did not consider the two different meanings of ton. And on top of this all, this ignores all the upstream emissions to generate the gasoline, which is greater than the 15% which you said was "not nice."

378.5 * 749/1000 * .87 * (15.999 * 2 + 12.011) / 12.011 = 903.7

still well short of a ton

You seem to be accepting that I was able to find your error on the single significant figure.

However, I already told you that I was using a US ton, 2000 pounds, 907kg:

https://duckduckgo.com/?q=1+ton+in+kg

Additionally, you are not including the 3-6 pounds per gallon in upstream emissions for gasoline.

Let's recall that this all started from the phrase "about 100 gallons of gas convert to a ton of CO2" and that when you quotes, you omitted the "about" so that you could try to make your incorrect quibble relevant. So at this point I would like to call this a very "not nice scientifically" departure from anything relevant, but I'm all ears if you were going somewhere interesting with this.