So long as you're not placing a large load on the engine at low RPM, you should be fine. At lower RPM, the oil will form a thinner film between parts, and will have less ability to protect your bearings at high load. For the same reason, don't let the RPM drop below your engine's natural idle speed or you may begin to suffer camshaft and rocker arm wear.
All IMO, of course!
__________________
|