I purchased a 1990 Ford E 350 460CI fuel injected motorhome. Previous owner never answers my calls. What type of oil would you recommend I use in my motor? It has 55,000 miles. I know it is a matter of choice but I need somewhere to start. I live in Idaho and it gets cold in the winter but I plan on using in the summer months. Book says to use 5w/30 but I am confused on brand synthetic? Motorcraft?

 

This vintage motor was designed around 10w30 conventional oil so that is all that is required, you can use anything from 5w30 to 20w50 in it depending upon ambient temperatures and engine workload, and synthetic or conventional is your choice. For a motor that probably only sees a small number of miles a year the brand of oil used won't make any difference as long as it's not some super cheap no name stuff, use a brand name oil and a Ford oil filter and you won't have any oil related issues.

 

As I remember from buying my wife an '86 Escort, Ford was using 5W30 as its standard oil weight. And that is what your book says too, so that is correct as a starting point.

I would use Motorcraft syn blend, which tests very well, but you could alternatively use any oil that is on sale and meets current SN specs. They're all fine and no oil that meets these specs will either damage your engine or make it live longer. I would recommend a Motorcraft or Purolator filter with a silicone ADB valve.

If you want to make a hobby of motor oil choices, you can start hanging out on bobistheoilguy.com but I have hobbies that are more fun.

George

 

Use synthetic.

 

Great! thanks for your input.