Ford/Mercury Motor Oil Recomendations. - Ford Forums

adrifter2 · 03-27-2008, 09:42

I'm new here to the forum, and have a question about the 5W-20W motor oil weight that Ford/Mercury recomends for their cars.
I have purchased new Mercury autos over the years, and just yesterday I purchased a new 2008 Mercury Sable.
I have also been a user of major brand over the counter Synthetic Motor oils for years, with great results.
I didn't realize that Ford/Mercury, as well as the majority of American and foreign car manfacturers are now using 5W-20W weight motor oils.
Does anyone know the reason for this, as opposed to using 5W-30W or 10W-30W weight oils?
It would seem to me at my age of 72, that 5W-20W would be too light a weight oil for even hot weather driving conditions, with outside air temperatures in the 90's or 100 degrees. Especially in stop and go heavy traffic situations with city driving.
But could 5W-30W synthetic motor oil be used in place of any factory recomended 5W-20W oil?
Thanks for any advice.

adrifter2 · 03-29-2008, 06:58

I have not received any answers to my post as yet, even though it has been read by quite a few.
So I have to think my thoughts about 5W-20W motor oil is too light weight an oil to use.
So I'm switching to my choice of 5W-30W synthetic motor oil , for my 2008 Mercury Sable.

**360ci** · 04-26-2008, 19:30

5W20 is used as a fuel economy benefit. If FoMoCo can benefit 1mpg from the entire fleet to increase their CAFE regulations, then that's what they'll do. The 5W20 is recommended for my '99 Taurus, and that's what I use (Amsoil full synthetic). 0W20 is also a good choice and can offer greater fuel economy benefits. I don't burn 5W20 at all in my '99 'Rus, but I did burn some 5W30; 1/3 quart over 4000miles (synthetic). Still, nothing to write home about. I see temps from 40C to -50C throughout the year and never had any problems starting the car in cold weather without using the block heater when I should have!