Is the average car engine better at driving than the average light aircraft engine is at flying? I.E are cars generally more reliable at what they do.
I don't actually have any stats to back this up but I would bet money on a well proven design like the O-320 (as found in the PA28 for example) that is well maintained and not abused being significantly more reliable than a car engine. Go through the AAIB reports and engine failures in modern aircraft that weren't caused by carb ice or running out of fuel are rare.