Stock exhaust setup
If somebody can come up with a quick, clean-or-dirty and legal way to improve (i.e., macho-up) the idling exhaust note of the E500, I would sure like to hear about it. The car has a hair-raising roar/howl at WOT, but at idle it sounds like a Buick. I recently got to hear a new Infiniti M45 at idle - now that is one mean-sounding burbling and rumble.
If it sounds better, too, that's cool, but from the little bit I've seen, Benz exhausts tend to be overly restrictive and heavy -- which isn't surprising given the conservative image they choose to cultivate. Obviously removing some or all of these components would change the sound a lot, and probably for the better, but that isn't necessarily an overriding goal.
"Legal?" Let's not go there.

Fortunately I live in a state without emissions testing.
(Cats are a scam anyway. There is far too much sulfur in all pump gas to permit cats to have the beneficial effect they were originally intended to provide. Currently fuel runs about 540ppm to over 900ppm sulfur. The oil industry itself says it has to come down to about 150ppm for cats to be effective, and the auto industry, who is trying to defray some of the costs of meeting legislative emissions requirements, says it should be 30ppm. The EPA wants anywhere from 80ppm to 40ppm depending on who you ask. "Big oil" doesn't want to deal with the considerable expense. Sulfur bonds with most of the catalyzing surface before a cat reaches operating temperature, and it can't be filtered by the cat since the sulfur molecule is so similar in size to the platinum molecules used in the catalyst itself.)
(Cats are a scam anyway. There is far too much sulfur in all pump gas to permit cats to have the beneficial effect they were originally intended to provide. Currently fuel runs about 540ppm to over 900ppm sulfur.



