TW> That is corect. A 10W-30 is the same as a 10 weight when it is cold but   
   TW> the oil changes as it warms up to the equilivent of a 30 weight when   
   TW> hot.   
   TW> Here in SAn Diego California where the weather is fairly mild   
   TW> I had been running 20-50 oil in my cars.   
   TW>    
   TW> I have recently changed to using a full symthetic and will be using the   
   TW> 10-40 in my older truck with a little over 100,000 miles on it.   
   TW>    
   TW> Becasue of the increased gas miledge helps then meet the CAFE standard   
   TW> most car manfacturers recommend the 5-30 or 0-20 in their new cars   
      
   Thanks for validating that for me.  I never knew about the additive that makes   
   the weight different in cold/hot conditions.  I just knew the higher numbers   
   meant "thicker".   
      
   All I know is that cold start value tap that lasts for about 20-30 seconds   
   happens more often and louder when we have cold weather.  On hot days, it   
   doesn't do it much if at all.    
      
   - Mark   
      
   --- WWIVToss v.1.50    
    * Origin:  http://www.weather-station.org * Bel Air, MD -USA (1:261/1304.0)