Hi Nick, As you well remember discussing on the phone regarding my '82 Rolls Royce Silver Spur, 6.75L, I was telling that I was having problems with predetonation even when using premium fuel per the manufacturers recommendations. Also I mentioned that the idle was little rough as well as some smoking out the tail pipe, in essence, burning oil. Additionally, my gas mileage was only 9 mpg. Now, after installing the Aquatune ALL the problems I mentioned have been solved! No more predetonation and I am now using regular grade fuel. My mileage increase has gone up 16 mpg even. The smoking it totally gone. Now for the funny part, honestly, I sometimes think that the engine has stopped running when I'm stopped because the engine is running so smoothly now. I have to keep glancing down to make sure that the generator light is on. Horsepower increase is absolutely great. I plan on buying a Bentley here shortly and will be ordering another unit for it. Thanks for this fantastic product.