10-30 vs 10-20 weight oil

[midiout]

I have used both oils - the 5-20W gives me much better mileage on the expressway. When I had the oil changed the second time, they put 5-20W instead of conventinal 5-30W. I found out later after getting 25.5 MPG, that "they" put the 5-20W instead of Ford recommended 5-30W. With the 5-30W , I could'nt get past 20 mpg. From now on, I will stick with Ford 5-20 semi-synth and Ford 820S filter. When I changed the oil last sunday, the Valvoline filter (V02) was two inches shorter then the Ford filter. The Ford service dept. says which oil does'nt matter. What are other members thoughts on this ?

 

[michael loibl]

I'm going to assume the title was a typo...10-30 vs 10-20 instead of 5-30 vs 5-20. Assuming this is what you meant, there is very little viscosity difference between 5-30 and 5-20. I doubt there would be any more than a half of one MPG difference with identical opperating conditions, which is in itself basically impossible.

My 2001 honda accord EX V6 calls for 5-20, which I use in the winter only. The rest of the year I run 5-30, and run hard she does. I never tried 5-20 in my explorer, but after 6 years in the accord, I cant say I saw any difference in mileage.

 

[tipdrill]

was the 5w20 synthetic and the 5w30 dino?