Up north in Erie, PA where I live, I have NEVER EVER replaced a vehicle due to powertrain or mechanical failure. It is always because of rot. That said, most vehicles started to show signs at 10-15 yrs, and were junk at 20-25 yrs.

Krown, Fluid Film, or new bar & chain oil mixed with your favorite things is the one and only solution for our pot metal vehicles.

I once watched a vehicle manufacturing video and it was stated that a new car begins to rot the moment it is assembled from the spot welding and machine welding. Have you ever replaced a body panel and notice it will start to bubble / rot from the inside wherever you mig welded it only within a few yrs? This is why.

My thought is this: let it be made of crappy metal, let it rot in 5-6 yrs, but price it accordingly. Trucks today cost about as much as houses.

 

I'd recommend Krown rustproofing. Had it done on my 2008 f150 and ive had it 5.5 years and its 8 now so...

 

With all this talk of rusted out rockers and also my personal experience, it got me to wondering if the 2015 & up models have been redesigned to eliminate the triple wall rocker panels. So I remembered the "ask an Engineer" forum, but apparently I can't post a question there. How do ppl get qualified to ask questions. Moderators only, or something like that? If I decide to buy one on the aluminum bodied trucks in the future, I'd really like to know if I need to start drilling panels in order to reach all of the hidden areas where corrosion can start. And I believe, even though these are aluminum, they still are going to have adverse reactions to moisture and salt.

 

I just noticed on my 2009 that I have some bubbles of rust starting on the very top. About the size of a quarter or so. Guess I better fix it before it gets out of hand

 

Wow! Good read; terrible gut feeling!
I have a '14 STX SB 4x2 and live in Coastal SC. I've noticed Live Oak leaves and sand in every nook and cranny of the truck lately, from the cowl down. Had plans to start a wash/detail of my truck tonight. This and the linked threads added a couple hours to the job. If nothing more than for peace of mind....and of course, resale value!