Don't rely on your odometer to tell you when to change your oil or replace your brakes on a track-driven car. That's just asking for something to break when you least expect it.
Instead, steal a page from the aeronautics industry and install an hour meter to stay on top of your maintenance schedule:
Since I got so many questions about it last time, here's where you can get the parts I used:
And yes, there are cheaper hour meters and inductive tachs out there. I went with these two because they are designed to withstand more moisture, vibration, and dirt than the cheaper ones. And they're calibrated better than the cheapos.
Still, if you want to give those a try, there quite a few out there:
PS: While the 85000 series Hobbs meters are perfect for cars, boats and motorcycles, they are not for certified aircraft. So don't go sticking this into your Cessna 152.