This past fall, I met with Aron Cheek and had a groove cut into my Buick's throttle body. Everything went smoothly. Aron and I went for a test drive, the car had good power, no surging. I did notice a slight mileage increase. Recently, I was reading an article where Ron had talked about brake boosters being a common culprit for vacuum leaks. I tested mine with a vacuum gauge and it held zero vacuum. I'm in the process of getting the booster changed and will check mileage after that.

Both Aron and Ron were very helpful in getting the groove installed and in talking through possible solutions to problems.

I think you will find a reasonable increase overall, as Ron has also mentioned a number of times... The Groove does its best work with a higher average vacuum. If the leak in the booster was that bad, I could only imagine what the performance "wasn't" prior to the Groove.