Originally Posted by Brosef
Highly unlikely that HFC's could do anything to negatively affect the motor. They are, however, illegal in most states as you're messing around with the emissions of the car. HFC's do make the car manufacturer's case a lot easier though in the event that they want to deny warranty coverage.
A tune and pulley have much more direct effects on the car, and I would never trust a salesman's word on those not voiding warranty. Frankly, I'm surprised he/she would say that. A tune would make it very easy for BMW to deny warranty coverage if they wanted to. Not so much a pulley, but if your power steering goes bad, forget about it.
Yeah hes a young salesman. Said he has a few customers that have done Active Autowerke's stuff and have had good results and no problems. He told me to go with Active Autowerke's tune because BMW's computers can't detect it.
What mechanical problems could arise from using HFCs though? I mean, could they directly cause any problems with the engine?