When you see some rust on a 4th gen Ram, keep in mind that unless you check it out personally, it could be 14 years old.
Cold and salty roads is actually a season around here. All truck makes seem to have a problem with the rear wheel arches rusting, usually as a first sign. Tailgates usually follow. GMs have a reputation for rotting cab mounts, cab corners and on older gens, the frames would perforate badly. Pre-aluminum Fords had the same problem with cab and bed mounts, doors and rockers. Third gen Rams would rot at the rear cab corners.
Haven't seen too many rusty 4th gen Rams...yet, and when I do its never in the rockers.
I noticed that on DTs Ram has opened up the flush-outs at the bottom of the front fenders. That was a trap area on 4th gens especially for leaves, pine needles and such. I flush that area at least once a year with a garden hose.
The only area that I think is still susceptible is the space between the outer edge of the rear wheel arch and the rear wheel housing. Its covered on trucks with wheel well liners, but if you look at a truck without liners you will see what I mean.
All-in-all, around here Rams of the last two generations seem to hold their own.
Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Build date: 03 June 2018. Now at: 044927 miles.