Posted by Alan Bowes on January 18, 1999 at 10:10:30:
In Reply to: synthetic oil OK? posted by Alan on January 18, 1999 at 07:44:01:
Well, there have been numerous discussions on this topic, but to summarize my thoughts VERY briefly, I would say that if you have an engine that is internally quite clean (or if you have been using a detergent oil on a regular basis), I'd go ahead and use the synthetic oil. I've been using synthetics exclusively for maybe 20 years and I've had superb results. Synthetics have been improving constantly. They now have much lower ash formulations that provide better start-up lubrication, better idle-speed oil pressure, less deposits (especially on pistons), and improved viscosity constancy over a wider temperature range. The newer formulations also don't break down as easily at extremely high temperatures and pressures as the earlier stuff. All in all, I'd say they're significantly superior to non-synthetic oils in nearly every respect. You can also expect to pick up a couple of horsepower from reduced friction, and maybe a touch better fuel economy, but don't expect anything earth-shaking.
If your engine is rather dirty inside and you've been using a non-detergent oil, there is a chance that switching oils could loosen up old deposits of sludge that could do some surface scoring before they eventually get trapped by the oil filter circuit.
Alan