I purchased a 90 Impulse with 247K on it. I knew the car was very tired and needed a pick me up, So I tossed in some Lucas to see if this stuff actually worked. WOW does it ever, I noticed right away the change in sound of the motor, next to no smoking or knocking, This stuff truely is amazing. I would shift this little car at an amazing 8200RPM and it would beg for more, lol with out Lucas I would have been shopping for a new car. If you have any doubts about this product forget them, try it, it really does work. I tell every one I know to use it they also agree "best stuff money can buy"