Fuel additive/ cleaner

[bionoc]

I had been to the dealer recently with a with a window issue. While I was there, they suggested that they add a fuel system cleaner to the fuel tank. They said that this should be done every 6 months. I didn't take them up on the offer as the manual states that fuel additives are not recommended.
My car is a 2009 model 5.5 V8 petrol. Is it normal nowadays for Mercedes to add this fuel system cleaner twice a year?

 

[tron]

I very much doubt it. I put a bottle of the stuff through my Diesel though. Gained about 1.5 MPG. 3 to 4%. Back in pocket in a fortnight.

 

[Simon_M]

Think it is a dealer profit making tool like Starguard.

 

[Dave Barlow]

I very much doubt it. I put a bottle of the stuff through my Diesel though. Gained about 1.5 MPG. 3 to 4%. Back in pocket in a fortnight.

I can quite believe that.
I use Forte products in all my vehicles and the improvement is marked.
The one exception is fuel tank cleaning.
I use a Briggs & stratton product used for preserving fuel in mowers etc over the winter period. Apparently it keeps the fuel stable and water in suspension. My 70s 2 stroke motorbike idles and accelerates better with a drop of this in the tank.

 

[bionoc]

Think it is a dealer profit making tool like Starguard.

I'm thinking along the same lines. It seems that nobody else on here is being offered this treatment by their dealer