Actually the answer is the question. You save money by living a simple life. In our case we live close enough to walk or bike to everything except the trail head. We have a large section with huge veggie patch, hens and a mushroom farm. Inside we sprout our own fresh sprouts, make our own cheese from locally sourced milk, bake bread in a breadmaker, cook as much as we can in a slow-cooker or microwave, only heat our living areas, and then only to ~15C/60F. No air con. We do almost all our own repairs to just about everything, buy mostly second hand, and buy most of our foods fresh, in season and locally grown. We have a campervan for trips out of town, but it stays in the driveway the rest of the time. We eat cheap foods. You can do a lot with rice, cabbage and chick peas :) Avoid bars and restaurants like the plague, no cosmetics or deodorants, no broadband, no digital subscription, our computer is 10 years old, prepaid cellphone for emergency use only. No overseas trips. We buy everything on our credit card to collect reward points, but pay it off in full every month so we don't pay interest. This lifestyle allows us to work a four day week and still have time to hike and pursue other fun activities aside from keeping the home running. We really like our lifestyle, and don't feel cheated in any way. Plus all that activity at home means you don't have time to miss all the electronic addictions that can suck away your time and money. Aside from that, we are lucky in that we live in a country with mostly socialised healthcare, so don't live in fear of injury or ill health as much as many Americans. We get 5 weeks per year paid vacation, and only work a 7.5 hour day. I live within an hours drive of fanatstic hiking, water and snow sports areas, and some of the finest scenery in the world. My American family are always trying to get me to move back to the US. They don't understand why I want to live somewhere where I "earn so little". They totally miss the point that I have so much! I even like my job...my biggest weakness is gear :(
"If I ditch my car, I can't hike except on the paved sidewalks around my home. A car is essential to reach the trailheads in this area. Portland itself has excellent public transit, but there is absolutely no transit to Mt. Hood or most of the Columbia River Gorge."
Where there's a will, there's a way. We often go with friends and take just one car. In my younger days I joined backpacking clubs and shared rides with other members. I also met a lot of fun people ;) Just aim to use your vehicle as little as possible while in town, and ditch the guilt when you DO decide to go away. It's only in the last 10 years that I have owned a car (since I left the US 30 years ago).