V4 vs V6

Some of the fastest cars in the world have 4s and 6s. I give you the Lotus Elise and the Porsche 911.

I’m 56 too. But only for a few more months.
4 cylinder and 6 cylinder engines have come a loooong way. You’d be amazed at the pep that 4-bangers have, even in family sedans. Generally V6 engines will idle a tad smoother, but they’re also s tad more expensive to get anything done on because they have more stuff under the hood and because the rear bank (on a transverse engine) can be hard to access.

Test drive both and get the one you like best.

From what you said about yourself, I think that you will be perfectly with a 4. Modern 4s are smooth and quiet, and have adequate power for ordinary driving. A six would be more expensive, more powerful, a bit quieter and a bit smoother, just a reliable and long-lived, but more expensive to maintain and repair, and use a little more fuel, but you would probably be happy with a six as well.