The average annual expense of riding a basic bike would be $100 to $300. (tubes, tires, replacement of bike parts - labor is free, since you will figure out and work on your own bike).

The average annual expense of riding a basic car would be $2,000 to $3,000. (annual registration, insurance, gas, oil changes, replacement of car parts, and occasional paid labor).


If you are replacing your car with a bike and you are getting rid of your car, you will save about $1,900 to $2,700 approximately. ($2,000-$100 to $3,000-$300)

If you are keeping the bike and are using it for your daily commute and running errands, basically making bike as your primary mode of commute, and also keeping your car, for traveling long distances, you will save just the gas spending, about $1,000 to $2,000, annually, since you will end up paying for annual registration and insurance on your car, anyway.

P.S. This is an approximate estimate of savings of yearly variable expense, in my personal case and if it was me pondering this situation. YMMV.

On Edit: Agree the savings may not be significant, depending on what job you have and what you make. However, when you ride a bike, you will gain significantly health-wise, and when you do your research and fix your bike on your own and get your hands dirty, you will feel more manly about yourself.