Learn preventive maintenance. Performing your own preventive maintenance can also save you big bucks — and it can be a valuable learning experience. At the very least, learn how to change the oil. As of this writing, an oil change in a Cessna 172 at a shop near my home costs about $176. Changing the oil yourself adds up to only about $70. That's a $106 savings you could spend on avgas or put toward a new instrument. And there are many other tasks you can do that not only save money, but also give you the opportunity to learn more about your airplane. CFR 14, Appendix A to Part 43 (c) lists a surprising number of tasks most pilots are allowed to do, including changing tires, replacing a battery, and replacing and cleaning spark plugs. If you haven't done these tasks before, it's wise to have a mechanic check your work the first time you do the job. Builders of amateur-built aircraft and/or owners of light-sport aircraft have a wider range of options, including eligibility for a Repairman Certificate (CFR 14, 65.104). For complete information on what you can and can't do on your airplane, consult CFR 14, Part 43 and Part 91 Subpart E before starting any work. You'll find all the CFRs online at www.ecfr.gov.