I’m running an Edelbrock supercharger on my 2019 Mustang GT. Should I go with 5W-40 or 5W-50? I’ve got Liqui Moly on hand. Any advice?
Roush recommends 5W-50 for their supercharged cars after 2018. I’d guess Edelbrock suggests something similar, but you might find it in their documentation.
For high RPM engines, you usually want lower viscosity oil for better flow. But you also need enough viscosity to protect the engine under pressure. I’d lean towards 5W-40 for better valvetrain protection.
@Curtis
I think you mean higher viscosity for more protection.
Merritt said:
@Curtis
I think you mean higher viscosity for more protection.
Lower viscosity flows better, especially at high RPMs like 7,000+. It’s critical for parts to stay lubricated.
@Curtis
But thinner oil offers less protection, especially for a supercharged engine. It sounds like you’re contradicting yourself.
Merritt said:
@Curtis
But thinner oil offers less protection, especially for a supercharged engine. It sounds like you’re contradicting yourself.
It’s about balance. Thinner oil flows easier, which helps avoid starvation at high RPM. Less protection is better than no lubrication at all.
@Curtis
Oil starvation isn’t likely in these engines.
Merritt said:
@Curtis
Oil starvation isn’t likely in these engines.
Ford uses 5W-20 semi-synthetic as the default, probably for fuel efficiency. If you’re worried about performance, pick what makes sense for your setup.
@Curtis
Actually, Ford specifies 5W-50 for cars like the Boss 302 and Track Pack models. It’s right there in the manual.
Merritt said:
@Curtis
Actually, Ford specifies 5W-50 for cars like the Boss 302 and Track Pack models. It’s right there in the manual.
The Boss 302 has different cams and operates with a different oil phasing algorithm. Track Pack models also have less restrictive ECU settings, so it’s not exactly the same.
@Curtis
But the engine itself is the same. The thinner oil is just an EPA thing.
@Curtis
Here’s the factory oil chart for reference.
Merritt said:
@Curtis
Here’s the factory oil chart for reference.
Roush also recommends 5W-50. Some people swear by 5W-40, though. At the end of the day, it’s your engine. Go with what you trust.
@Curtis
Motorcraft 5W-50 tends to shear down to 30 weight over time. Honestly, as long as you’re using a quality oil, it’s not a huge deal.
My Boss 302 says 5W-50 on the cap, and that’s what I use with my supercharger.
Ford recommends 5W-50 for track and supercharged setups. Roush, Whipple, and others say the same.
You can use 5W-20, but something thicker like 5W-40 is probably better for this setup.
Isn’t 5W-20 the standard factory oil?
Curtis said:
Isn’t 5W-20 the standard factory oil?
Yeah, but supercharged engines usually need something different.