Hi,
My 2001 Escape is supposed to have 5 - 20 weight oil.
I have been using Schaeffer synthetic. Lately my local supply shop only carries Schaeffer 5 -30. Would it be harmful to my engine if I used that instead of the 5 - 20?

 

Just about all manufacturers recommend using a certain grade oil. After much testing and the results obtained they recommend what will protect the best under most operating conditions. Your best bet is to use what is recommended in your owner's manual. I have seen engines run with other oils than recommended and some engines just don't maintain the close tolerances that were originally built into the engine. You usually don't have any of those problems if you stick with the recommendations in the owner's manual.

 

MFGs went to the 5W-20 about 2000-2001 to help them meet their CAFE requirements. My 2004 Freestar per FORD requires 5W-20, but I have been using AMSOIL's 5W-30 for the past 178,000+ eventless miles. My 2010 Lincoln MKZ per FORD requires a 5W-20 semi or full synthetic, but I use AMSOIL's 5W-30 in it (about 27,000 miles on it). Heck, even my new 2015 F-150 3.5 ecoboost calls for a 5W-30. The 5W-30 will maintain a better film strength than the 5W-20 at high temps, but a 5W-20 will absorb and release heat faster than the 5W-30, but not by much. The 5W-20 pumps easier at operating temps than the 5W-30, thus resulting in the needed increase in MPG by the MFG to help meet the CAFE requirements. The weight that you use is your call.

 

Hi,
Thank you so much for your helpful responses. Schaeffer full synthetic is the brand I have been using and gas mileage is important but not the kind of minuscule savings I would have using 20 vs 30. My engines are both over 100000 so I am going with 30W oil.

 

I'm with you there. Also, the 5W-30 weight oils normally will have less evaporation (NOACK Volatility Test) than the 5W-20 oils will.