I have a Fiskars splitting axe and LOVE it. Not sure the size, but it is the standard they sell at Home Depot for to split your fire would with
When light camping I use my Ka-Bar it's a great multi tasker! Hope this helps.
Edit:
Okay so I've got the 28" Pro Splitting and for car camping it's perfect. It does the work I used to use a splitting maul for...not quite as affective, but does the job.