Last week, on my way to work, I got a “low gas” warning.  My commute to work is almost 43 miles, and I knew I could at least make it that distance without running out of gas. (About 25 more miles)

I had made a mental note to get gas when I left work, but that note must of got thrown away because I didn’t remember until I was in my driveway safely at home.  (43 miles later)

“Ok, I gotta get gas tomorrow”, I told myself.

The next two days I left the house only to get lunches and dinners.  Oops.  (4 miles, approx.)

My wife asked me to drive 8 miles in the wrong direction before I go to work the next day.  By this time, I have completely forgotten about my gas issues.

I made her errand, and was about 15 miles into my journey to work when I broke out into a cold sweat, realizing I was WAAAAY past my low gas warnings.  (23 miles)

I got off the freeway and found a gas station.

Eagerly awaiting to see how much gas I needed, I was dumbfounded when the meter showed only “10.41 gallons”.

Huh?  Consulting my owners manual, it said I have an 11 gallon tank, and adding up the miles I drove past the warning light comes to about 90 miles.  And since I get on average 44 miles per gallon, that would mean my check engine light turns on when I have more than 2 gallons left in my tank.

And the weather was 86 degrees out, so there is no argument that the gas tank “bladder” had constricted and hence had a maximum capacity which was less than 11 gallons.

In other words, I can have 20% of my tank left, which gives me about 100 miles, and my Prius gives me a warning.