Anyone using Slick 50 or any other additive. If so what additive and what have been the results (life, power, etc). I have a 500EFI (roller rockers).

I've stayed from that stuff--went with Castrol semisynthetic oil for my EFI454's with 400 hours on them and change oil and filters religiously. I met Andy Granitelli one time (STP fame) and he was great guy but more salesman than Petroleum engineer--

FWIW

I tried that stuff several times in a couple cars I owned. Never saw any benefit.
Stick with a good synthetic or semi-synthetic you'll be better off.

Most are snake oils as they say. But I have used the prolong and did a test with it in my Scarab blower motor.When I first tried it it lowered the oil temp between 7-10 degrees .Smokey Yunick endorsed the Pro Long at one time .

I hear for some of the engine builders that some will impregnate the cylinder walls and not let the rings seat.Larry Meaux did one and had to re hone the block for the rings to seat

Rob

Thanks for the input, kind of what I thought. I used Slick 50 in my '84 (then new) Toyota Supra, no noticable difference in temps, life or performance. Sold that car with 100k miles, do not know what happened to it after that.

I use Restore in my '93 Suburban, which has 245k miles on it (yea it is old with high mileage, but it has never caused me any troubles, never had so much as a valve cover off and it still looks good). There is a noticable difference in power on that old engine when I use it.

I know there has been many threads on synthetic oils and roller rocker engines, what has been the conclusion good or bad?

Google it and you'll find a few FTC issues and lawsuits related to that and other "additives".