floormat versus carpet which is better to prevent rust.
 

I have seen opinions all over the place.
Rubber mats trap the water, cause rust.
Carpet padding holds the water, causes rust.
Carpet lets the water dry, prevents rust.
Rubber mat keeps water out, prevents rust.

I have seen rust under both, and no rust under both.

I am wondering if these differences may be tied to overall humidity in an area, the usage of the vehicle, or some other factor.

Let's see what we can come up with. Any input is appreciated.

Re: floormat versus carpet which is better to prevent rust.
 

Its called maintenance and making sure your windshield and nowhere else leaks water.

The majority of the rust you see on these trucks is from leaky windshields.

Re: floormat versus carpet which is better to prevent rust.
 

I redid mine in bedliner material. Looks sweet, easy to clean, no way it will rust

Re: floormat versus carpet which is better to prevent rust.
 

I had bedliner sprayed on the floor and up the back of the cab on my 76 and I did not like it. The floor was very hot around the transmission hump, when it rained or my shoes were wet my feet would slip around on the floor, and the texture wore off around the pedals where my feet were.

Bedliner sprayed on top will not stop rust that comes from the bottom of the floor pan, or runs down the kick panel from the windshield and collects in the corner.

As was mentioned above, fix any windshield leaks first. This is not as easy as it sounds - there are lots of places and reasons for a windshield/cowl leak.

I would just make sure your leaks are fixed and your floor/kick panel areas are in good shape. Then prime/paint the areas as necessary. Then get a good sound/heat proofing mat. Then install a custom fit carpet - usually bought online. Then get Huskyliners (not floor mats, liners with the upturned edges) or Weather Tech liners. I got some black exercise mat from Walmart and installed it between the floor mats to cover the transmission hump because I have a 4 speed stick. If you have an automatic you can get Huskyliners that cover both sides and the transmission hump in one piece.

If you get good floor liners your carpet will remain in good condition for the life of the truck - they will keep dirt and liquids off the carpet.

Even factory rubber flooring wears out, and they do have a type of padding under them. Also, rubber flooring usually doesn't fit very well around the transmission hump - tends to bunch up.