I know there are many good threads and debates out there but a new indy mechanic I found here in NJ w 40 years on German cars told me 87 is fine, 91-93 is a totally unnecessary waste of money, and just need to add a single bottle of fuel additive every $20K or so. He was adamant, and no benefit to him either way. My questions:

1) Our manual says not less than 87, but higher is recommended. I accept that higher octane gives better MPG, but what about carbon build up or other issues ? I've been using premium most of the 10 years I've had it, and no issues of any kind that would relate to octane. Part of my says "if it aint broke", and I don't "need" to save $150-$200/year on gas but prefer not to completely waste $150-$200, as my indy insisted was the case. He said the computers now adjust to 87 to prevent knocking, so no need. So .... for the 10 millionth time, should we use premium or is 87 just fine ?

2) Fuel additives - I've seen/read accounts where they either do nothing or worse screw up the engine. As stated, I've been pretty lucky so far w my B7, no major issues, mostly just stupid, frustrating Audi stuff. I'd like to keep it that way. I know Audi actually sells their own fuel additive that's only about $10, I assume anything Audi-branded is at least benign and probably of some value. Should I just get that ? Every other additive (Sea Foam, Techron, the red stuff) all have anecdotes on the web swearing its great or worthless or harmful.

BTW what prompted this is I had to go to the dealer for Takata recall, and while there I asked if they had any preventive service recommendations since I'm only at 83K miles and I'd like to get another few years at least. They said car in really good shape, but they recommended fuel cleaner service for $199, so I called my new indy to discuss. Only possible symptom I have is starting often takes a good 5 seconds or more, spark plugs are 35K miles ago, so no particular or obvious symptom of anything.

Part of me thinks ignore everyone, stay on path, no additives and stick w premium. That has served me well for years with this car.

Thanks for any thoughts.

 

Kap, the car is always going to be at its best with Top Tier fuel of 91AKI or better.

 

Replacing the fuel filter and cam follower may be the best fuel related things to do - you will be amazed at how much gunk will be in the fuel filter and the follower change is damage prevention and ensuring your fuel pump operates properly.