Projammer - I come up with a different total for you. 30 mile round-trip for work is 150 miles per week. Add an extra 50 for running around (could be less but the number is even). Multiply X 4 weeks. 800 miles per month. Divide by 40 mpg and you’re at 20 gallaons per month.
I’m at about 90. I drive about 1800 miles per month (round-trip commute is 65 miles) and get 22 mpg.
I work from home, so I don’t use too much gas - but I make a trip to Mom’s every big holiday and at least one of my doctor’s is 2 1/2 hour drive away. I don’t see him too often, but it is a mixed bag. I’m guessing I fill up less than twice a month, so less than 20. But I threw in “extras” just in case and said 20-30.
My work commute Monday-Friday is by train, as is my “fun” trip downtown on most Saturdays. These trips are wholly by train and foot. Although the trains are diesel-powered (Metra), they’re quite full even off-peak and weekends, so I doubt my share of the train fuel is significant.
I drive my 12-year-old Ford Escort sedan only two days a week, and one of those days is for a short errand. I use about one 12-gallon tank of gas a month. My goal is to go a month between fill-ups, and I always wait until the “low fuel” light has been on for a while. In practice, I go anywhere between 20 and 30 days on a tank of gas.
I wasn’t sure if it was 1-5 or 6-10 ( guessed the latter). My car is about 3 1/4 years old and has 9500 km, so that is, say 3000 km, maybe 2000 miles a year. It probably averages about 30 mpg, so that is, say, 70 gallons a years, which is around 6 gal/month. But in fact, much of that is driving between Montreal and NYC, which uses roughly 25 gallons per trip and I usually make two a year. I didn’t buy gas between January and June, when I put in about 35 litres (9 gallons) and my tank is now about 2/3 full. I leave for NYC Friday and I will buy gas over the border (where it is about 25% cheaper), fill it in NJ just before getting to NY and then near the border on the way home.
I mostly walk or bike, but do sometimes take a bus. But every municipal bus around here runs on CNG, so I can pretty legitimately say none.
Except for this. I do try to eat local, and really the per-mile energy cost for a bicycle even considering construction and maintenance and such is pretty damn low. I mean, sure, you might eat a little bit more - but that extra box of crackers is on a truck that’s going from place A to place B regardless, and you’re not driving to and from the grocery store to buy it.
I put 6-10. My car gets about 32mpg and I live about a mile from my office. In general though, I ride my bicycle to work. Of course, there are some months were I use more because I live in a town that has no 24 hour grocery store, so I have to drive about 38 miles round-trip to get to a Kroger, but that only happens about once a month. Most of the other is running from my house to my other family around town (it is a 2 sq. mile town, so yeah, not a lot).