I have to admit. This stuff works. Just don't expect a miracle if you have over 200 thousand miles. I have 318 thousand miles on my suburban and it did make a noticeable difference after about 3 days of driving around town. Only thing it made my temp get a little over normal but i figured it had to to burn out the carbon but for the most part it does work. I would say this would be a good once a year treatment for preventive maintenance.

Serrapeptase has made a tremendous difference in my ability to function... The only change I have made is this product and I can walk better (without a cane) and my stamina is greater (go most of the day without resting for long periods of time)... My blood-pressure is significantly lower.. ETC ETC ETC... I would recommend it to anyone with hardening of the arteries or bad circulation in the lower limbs... A+A A+ A+