Longevity: any modern combustion engine (easily the past twenty years) should last 200k+ miles. That is the engine block, pistons, crankshaft, camshaft, valve cover, and valves. Gaskets fall under routine maintenance. The valves are the weakest and most vulnerable component, but as long as youre doing routine maintenance and not trying to drive with a misfire, that 200k figure is easily achievable.
The V6 might have a
slight
edge due to likely lower average RPM.
Cost: Costs should be nearly identical in general. That being said, more cylinders means more components.
The I4 will have a slight edge due to less components.
Acceleration: From a general standpoint, youre comparing a small V6 to a very large I4, and so despite being technically smaller, the I4 isnt having to waste as much energy cycling the two extra cylinders.
I would give the I4 the win here, and my experience with small V6 would say a 2.7L would feel very sluggish.
Im assuming both options are FWD and weight appropriately the same. I havent worked on cars in a long time, but as an incredibly generalized statement for Japanese cars they do a solid I4 and a good enough V6, and American tends to do better with a V-block over Inline. Anything European should be fine either way.
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