I have a combination. I do use a spreadsheet to keep the overall data. But I use an At A Glance auto record book, that I keep in the car. It is a very handy booklet that has tabs, for gas, oil, repair, lube, tires, notes and some blank pages. I have one for each car.
Auto Record Book, 3 3/4" x 6 1/8", Black, AAG8013505 (this is the Amazon reference) it was listed at $12 USD when I just looked it up. Sometimes you can find them at office supply stores.