was talking to a mechanic at a Ford dealership the other day and we were discussing oil for my truck. I have 64000kms on an 08 and he said that after 60000kms the oil should be replaced with 5w30. He said because 5w20 is too thin. I just recently bought the truck and had just put Castrol 5 20 in, but after realizing it calls for 5 20 semi syn here in Canada. What oil is everybody else using, and is it based on your climate? It can reach -20c winter and +30c in summer.

 

Stick with the 5-20 in your climate. Especially if you're not consuming any oil. If your truck is consuming oil then you can try a heavier viscosity.

 

my '02 calls for 5-20 and i've stuck with it. although i did switch to synthetic.

 

When I bought my 98 F-150 it called for 5w-30. Ford now recommends 5w-20 but I stuck with the heavier oil. I've been running synthetic 5w-30 since new. 176,000 miles and still going strong.

 

5w20 is what I would use. Never had an issue on my 01 5.4L in 95* weather towing over 7K with the a/c on. It's what the engine is designed for.