Ok so took my car in for service. Oil change, transmisson service, air filters, fog light cracked. SA recommends that they put an additive to help clean out the engine when I change the oil. Car has 46k miles on it. Any harm to doing this?

 

I use Motul Engine Clean before I do my oil changes.

Should be a non issue.

Make sure it's manufactured from a reputable company.

 

I'm sure it is. I've been doing business with the same dealership (and SA) since I bought my C55 in 06. Never had an issue with them. They had just never recommended this before.

 

I'd be more interested in knowing how these "additives" actually work, or whether or not it is just snake oil to pad the bottom line.

 

^^^^^ +1 Mobil 1 (and other top brands) already add this "additive" so nothing additional will make any difference...