Gertrude ..
You might slightly be missing the point. I appreciate that you are likely to hear of more aircraft engine failures ... I think I even said in my post that these are usually more "dramatic" for obvious reasons.
What I would like to know is ..
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'm not trying to compare apples with pairs ... but I also know that there are similarities between the engines.
One answer that sounded quite decent to me was by Slopey who actually gave a reason as to why it might be more challenging for an aircraft engine to never fail (referring to altitude & the level of power that it is operated at).
S