At one time powerplant experts thought that wider bearing clearances and heavier oil offered optimum protection. Eventually they discovered that lighter oils and tighter clearances resulted in less wear, better power and better fuel economy. What's more the 10W-40 oils sometimes caused sticking of rings under some conditions. Not good.
Even the racers have changed. When I was wrenching a funny car in the seventies we were using SAE 50 or SAE 70 oil. I believe they're now running something around SAE 10 or 20, with much tighter bearing clearance. Live and learn. Paul On Feb 8, 2008, at 10:00 PM, Joseph Tainter wrote: > You can get just about any question answered on this group. > > About a month ago I bought a Nissan Xterra, just before we started > getting snow storms about every 36 hours. My timing has rarely been > so good. > > I am surprised to see that Nissan uses and recommends 5W-30 oil. The > only time I used this was my first winter in the Chicago area, many > years ago. The vehicle I owned then began to use it, so I've never > used > it since. I usually put in something heavier, 10W-40, 15W-50, or > 20W-50 > (in summer). And for several years I have been using synthetic oil, > which flows so smoothly that I don't see the need for lightweight oil > even in very cold weather. > > I'm wondering if anyone knows why a major manufacturer would switch to > lighter-weight oil. > > Thanks, > > Joe > > -- > PDML Pentax-Discuss Mail List > [email protected] > http://pdml.net/mailman/listinfo/pdml_pdml.net > to UNSUBSCRIBE from the PDML, please visit the link directly above > and follow the directions. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
