A search on "vehicle maintenance software" will turn up more sites than you can look at.
Most of them are geared toward fleet users but I did a little quick looking and found one at
Software that appears to be free for up to 3 vehicles and is $24.95 for home use and will handle up to 7 vehicles. It can handle more if you pay more.
Personally I find it easier to use a simple spreadsheet to keep my motorhome log and tractor log.
On the motorhome I only log fuel usage. For maintenance items I punch holes in the receipts and put them in a 3 ring binder with the fuel log. I write notes on the receipts where applicable and have several pages of paper where I write down things like part numbers, when I changed generator oil, and so forth.
Receipts are good when you sell a vehicle because you can show the buyer how you took care of it. A log doesn't prove anything, it could be false information, receipts are proof.
Depending on why you want to log things it is often easier to just write them in a book rather than going to the computer, opening a program, typing in the information, and saving it.
I am a computer person, even make my living on a computer but a few years ago I bought a new Rolodex to use as an address and phone list. It's easier than using the computer.
Bill Tolle