Well, for what it's worth,

My dad swore by the Jacobs products and put them on all his cars - Cadillacs, Chevrolets and Buicks.

He was very happy with the performance, but I can't comment how it works on a 4.5.

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Paul S.

2001 E430, Bourdeaux Red, Oyster interior.
79,200 miles.

1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".