doing my own maintenance

and more to the point:

I am a skeptic as well, but I am equally skeptical of the american car industries need to sell everyone a new car every 6 years. The automotive industry is very powerfull. The same skeptism could be applied to alot of new car manuals these showing oil change intervals of 7500 miles. Why do so many swear by 3000 miles whereas these new car engines (made of some new kinda of metal I guess) only need new oil after 7500 miles. hmm....

M

7500 miles isn't so far really - modern oils are a lot better than the stuff we used to use in the 60's and 70's and the quality of the engines is a lot higher - better machining - plateau hones bores etc- so a lot less wear and swarf left in the engine.

I do have problems with some makes who now specify 16000 mile oil changes - this is purely based on lowering the costs of ownership to the fleet buyers who will get shot of the car at 80k so don't care if it's worn out at 85k.

I've only ever tried Slick50 twice - one occasion it made no difference at all, and on the other the engine siezed up the next day.

My Pan European (Honda 1100 bike) is now on 75k and is still like new on just oil and filter changes every 4000 miles. Rangey on 145k with the same regime and still doesn't burn any oil or rattle.

Good clean oil and filters and don't waste money on additives is my views.