Posted by Alan Bowes on December 17, 1997 at 20:47:19:
In Reply to: synthetic oil posted by T.KRALOVIC on December 17, 1997 at 20:04:09:
As long as you've been running a detergent oil in your engine, you should be able to switch to a multi-grade oil, either non-synthetic or synthetic, without any problem. I use Castrol Syntec 100% synthetic and it's been great, though I suppose a bunch of other brands would also be fine. You could spend a lot of time researching the pros and cons of different oils.
Note: If you switch to a 20W-50 non-synthetic oil, you might see a slight improvement in hot idle oil pressure, but I don't think you'd see much (if any) gain from 10W-40 non-synthetic. One of the advantages of a synthetic oil is its more stable viscosity index over a wider temperature range. Figure on spending 3 to 4 US dollars per quart. Watch for sales and rebates.