5w50 synthetic?

[52pu]

One of my customers has a newer Mustang with the all Alum high HP engine and ford recommends 5w50.

 

[KD0AXS]

Originally Posted By: 52pu
One of my customers has a newer Mustang with the all Alum high HP engine and ford recommends 5w50.



In that case, you'll want either the Motorcraft or Quaker State. As far as I know, those are the only two that meet Ford's spec for the track pack Mustang. If it's not under warranty, I'd probably just use Mobil 1 0W-40.

 

[A_Harman]

Originally Posted By: dave1251
Originally Posted By: A_Harman
The Motorcraft 5w50 is so shear-prone, it probably shears to a 40-grade when you pour it out of the bottle. If that oil is run hard, it ends up a 30-weight. So why not start with a 5w30 that doesn't shear?


I do not know of many 5W50's that are not shear prone even Red Line shears in 5W50 grade.


Yes. If I had a need for a 50-weight oil, I'd go with Redline's 10w50.

 

[Shannow]

Yep, if you need an oil with an HTHS of 4.4 (e.g. M1 5W50), I wouldn't target a 5W50 in the first instance.

 

[g8atl]

Motul 300v.

I recommend this after research I have done with a boss 302 that requires this weigh. Its the only oil that did not shear after 3k miles. Its expensive......

 

[dave1251]

Yes this is sound advice IMO. 5W50 is just pushing too much VII's.

 

[OVERKILL]

Originally Posted By: g8atl
Motul 300v.

I recommend this after research I have done with a boss 302 that requires this weigh. Its the only oil that did not shear after 3k miles. Its expensive......


But what if Ford expects it to shear? (which they probably do, they tested it...)

 

[SIXSPEED]

I've been using Mobil 1 5w50 in my 07 GT500 for the past few years. Its virgin viscosity is lower than the Motorcraft oil and it doesn't shear as much. I buy it locally at Napa when it's on sale.