I recently had this debate with (of all people) a parts guy at the dealership I'm buying my car from. I was wanting to pick up some top-up fluids to have around, and wanted some 5w50. He insisted I was nuts, and that they NEVER put synthetic oil in any of the 5.0's until about 20,000 kms (~12,500 mi), and that from the factory they all had 5w20 synth blend. I had a print out of the fluids section of the manual at home and had made my list from that, but didn't have it with me at the time. But it clearly says, 8.0 quarts 5w50 Full Synthetic.

Just wanted to confirm that he's nuts, and reading your owners manual is the best policy when it comes to putting in the right grade of oil? I assume my oil cap will end all debate as well.

Not interested in a brand debate, just want to confirm the oil I should be using for top-ups on a brand new car.

 

Not sure Ford does full synthetic from the factory but I do know it doesn't matter when and if you switch. And 5W-50 is the correct track pack weight, as your oil cap should tell you.

 

I was just going to say. Go by the trusted oil cap.

It is interesting. The track pack cars have a factory oil cooler and it is recommended to use a heavier weight oil???? You would think with an oil cooler that it would be recommended to use a lighter oil. Live and learn.

 

Parts guy is full of crap, 5w50 syn. is correct spec.

 

Thanks guys, much appreciated.

 

I also had to bring in my owners manual and show the dealership the 5w50 requirement for my Track Pack car. They were surprised, but agreed. I don't think the sales manager realized what my car required when he agreed to first 3 oil changes for free

 

Hopefully they actually put in 5-50w oil when they were doing it for free!

 

I will be having an oil analysis done at the next change, and if it comes back as indicative of not 5w20, then I will certainly be complaining!

The receipt I got stated 5w50 and I actually talked with the mechanic who did the change quite a bit (he has a 2004 Cobra and is a huge mustang fan), so I actually do trust they put in 5w50.

 

It should only keep the oil cooler, and not have anything to do with the recommended viscosity.