Engine restore.....These things do make you laugh. Nothing, and I mean nothing can restore an engine, except hard work and new parts.
If your looking for an additive that helps clean your engine etc, look no further than Slick 50. I have always used this on every service. It isn't cheap at £22 (IIRC), but it's well worth the money.
_________________________

K&N, 35mm droper, axle spacers, de-tango,
LED's all round, Retro Fiesta badge, wind deflectors.