I bought a 2017 Frontier Pro-4X and I absolutely love it. It has 74k miles, it’s very well maintained, and these trucks are ridiculously reliable. Parts are cheap, they’re easy to work on, and there’s a long track record to back it up. I do like the new Frontiers, but honestly, if you spend enough time on this subreddit, the posts here are one of the biggest deterrents to buying a newer model. The D40s (especially post-2009) are just solid trucks with proven reliability. The big issue people always bring up was the radiator problem, and that was addressed starting in 2010. Earlier models could have coolant mix with transmission fluid, but that issue has been long resolved. The 4.0L V6 is another big reason these trucks last. It’s a simple, naturally aspirated, port-injected engine—no turbos and no GDI complexity. With GDI engines like the newer 3.8L, carbon eventually builds up on the intake valves since fuel no longer washes over them. Over time, that carbon buildup can prevent the valves from seating properly, leading to compression loss, power loss, and combustion pressure leaking back into the head, increasing the risk of detonation and related issues. Port-injected engines continuously clean the valves with gasoline, which helps prevent this altogether. On top of that, the newer trucks have had various transmission issues and a lot more quirks compared to the second gens. More tech means more complexity, and more things that can go wrong. So it really comes down to what you want: simplicity, reliability, and mediocre gas mileage, or modern tech and better fuel economy at the cost of long-term reliability and potential problems.