I agree with the OP. I believe that people who don't see the savings are only looking at the immediate gratification based only on dollar amounts (as in only a time period between a couple fill ups) .

When I made the decision to buy a bike to commute to work about 2 months ago, I didn't look at the situation as "saving gas". I looked at is as "how long will it take me to pay off the cost of the bike and gear in terms of the price of gas". After number crunching my averages, I found that commuting at least 4 days a week for 3 months will make the cost of my bike and gear equal to the cost of gas I would have spent during that time period. And this was based on the price of gas magically staying at $4.09 the whole time. So every time gas prices go up, my bike is paying itself off even faster than expected. So, a month from now is when I will immediately see my savings.