When your only fixed living cost is truck insurance, you can save a large chunk of your income.
One San Francisco-based Google employee in this exact situation, who lives in a 128-square-foot truck in the company's parking lot, saves about 90% of his take-home pay.
Brandon — who asked to withhold his last name and photo to maintain his privacy — doesn't use electricity, and his phone bill is handled by his employer, meaning his one recurring cost is his $121 monthly truck insurance.
"I'm going for a target of saving about 90% of my after-tax income, and throwing that in student loans and investments," the 23-year-old software engineer tells Business Insider.
He graduated with $22,434 worth of student loans, and has paid it down to $16,449 over the course of four months. He expects to have the loans fully paid off within the next six months, which will save him thousands of dollars in interest that can add up over the standard 10- or 20-year repayment plans.
Saving on rent has also allowed him to dine at nice restaurants and enjoy San Francisco more than if he opted for living in an apartment.
The main reason behind minimizing expenses, however, is to save up for his eventual travels, he explains on his blog: "The goal of this whole intense money/resource saving expedition is to save money so that I can travel the world in four to five years' time."
The truck life is not only preparing him financially for future traveling — it's preparing him mentally, he says, by forcing him outside of his comfort zone: "If I do plan on traveling the world, I'll need to be comfortable with unconventional living situations, and this is certainly a good place to start."
After just five months of living unconventionally, he's already hit his "break-even point" — when buying and living in a truck became less expensive than renting an apartment — and is well on his way to building a travel fund.
You can follow the live-updating "savings clock" he created on his blog to see exactly how much he's saving.
More From Business Insider