Financial blogger Mr. Money Mustache retired at age 30 with roughly $800,000 in cash and investments. One of his biggest money saving tips is: ditch the car and ride a bike. He estimates Americans can save up to half their incomes by switching from automobiles to bicycles.

Also see: How We Got Out of $50,000 Worth of Debt

“You don’t even have to totally give up the automobile. You just have to use it less. So, instead of the usual strategy of buying two expensive cars and living far from work and then replacing your cars every five years, you can buy two old cars like I have. Bike to work. And that can make a difference in your auto costs of somewhere like $12,000 to $15,000 a year,” he calculates. “A lot of people aren’t even saving that much right now, so they’re more than doubling their saving rate — possibly even saving half their income when you combine that with a few other little lifestyle tweaks.” 

Also see: How Mr. Money Mustache Retired at 30

Mr. Money Mustache lives in Longmont, Colorado, a bike-friendly town, but even there he says only 2% of residents use bikes to get to work. “That means we got 98% room for improvement here and in a lot of other places. Every city I’ve lived in, I’ve always biked. If you start thinking, I don’t want to drive to work, then next time, that’s going to affect where you choose to live.”

Also see: Daily Habits of the Wealthy

Think you can make the switch to biking like Mr. Money Mustache? Connect with me on Twitter @Farnoosh and use the #finfit.