my brother-in-law has a 2004 focus lx sedan and in his service manual it calls out for 5w-20 motor oil.mine is a 2000 se sedan which calls out for 5w-30.He says if i switch to the lighter oil it will improve my mileage,my question is why the difference in the oils when both cars have the same 2.0 spi,and would it be safe for my engine to run that 5w-20 oil?thanks.
Ford used the 5W20 spec oil to meet CAFE requirements. Basically they have to average a certain mileage across the their vehicles in production or they get dinged by the government. The 5W20 oil boosted their overall mileage that they could continue to produce the gas guzzling SUVS and such. I doubt very seriously if you are going to notice a difference at all. From a 50W to a 20W you will probably notice a difference, but not from a 30W to a 20W.
I have a customer that has a 2004 Ford F150 and has used both the 5W30 and 5W20 and hasnt noticed a difference at all in mileage.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
Ford did it for CAFE numbers. If you had a fleet of Focuses you may see a 1-2 mile per gallon increase but not with just one. And you are corrct in that the 2 SPI 2.0L motors are the same. So in saying that you can use 5w20 and he can use 5w30 without any problems. Some people prefer to use the 5w30 as it "protects more in the winter". But I think its just a persomal preferance. Either way you should be fine.
My 2001 ZETEC calls for 5w20 and I think I used the 5w20 fow adout 5k miles and than switched to the Amsoil 5w30 and at about 25K I switches to Amsoil 0w30 and I new get 30mpg with the car where as before I would get no better than 28 on a good day(well...tank). It could have been me getting older, wiser and slower but I won't admit it.
thanks.
