AFAIK asphalt type material is aftermarket, not OEM. Asphalt-type could be OEM on older luxury cars, maybe? Every car I've ever owned (Pontiac, Olds, Chevy, Plymouth) came with jute* under the carpet, and nothing else, except my '69 Barracuda did have thin aluminum foil stuck to the floor pan from the cowl/floor pan joint rearward for about 18-24". The aluminum foil was on the driver and passenger sides, where people would place their feet, not on the trans hump. Apparently the foil was to deflect some of the engine heat.

This topic has been discussed many times here. Two approaches are (1) relatively light weight with aircraft materials, and (2) relatively heavy weight with asphalt-type material. Concerning asphalt-like material, one of the links below talks about using just enough in just the right place to dampen the sound of a panel without covering the whole panel.

If using asphalt material, it is important to tape over exposed asphalt edges, because engine or exhaust heat may cause melting and runs.

https://board.moparts.org/ubbthreads/ubbthreads.php/ubb/showflat/Number/6898589/site_id/1#import

https://board.moparts.org/ubbthreads/show...;gonew=1#UNREAD

https://board.moparts.org/ubbthreads/ubbt...ner.html#UNREAD

https://board.moparts.org/ubbthreads/show...;gonew=1#UNREAD

*"Jute" is what some call 1/2" thick or so layers of shredded and compressed cotton rags, however jute is a different fiber that is not cotton. Some use the word "shoddy", however shoddy is woolen, not cotton.


If you don't see two dolphins, you need a vacation.