Ford - Be Consistent!!

[Stooge]

I have a 2006 Mustang GT. Why does the V8 engine specify 5W20 yet the old-style 8.5" rear end specify 80W140 (not 75W90). I would argue that the rear gear has just as much potentual, or even more, to gain mileage with a lighter oil. Ford knows that the rear gear needs the heavier oil to be reliable (they've fixed alot using 75W90)- wonder if they also know that for the engine?

 

[toocrazy2yoo]

Want consistency? Break it while driving it the same way they show it being driven in the commercials, and watch them deny the claim for "abuse".

 

[mechtech]

Old style rear ends had hypoid gears, which are very tough on lubes. There is some sliding that takes place between the ring and pinion gears, at extreme pressure angles. Nothing in an engine, or even a modern transaxle [helical gears], is as tough on oil as hypoid gearing. too crazy - Great point - Ford is bordering on hypocricy.

 

[Fatboymoe]

Stooge, Check the specs. for the rear end again. It's an 8.8 in the GT and calls for 75-140 synthetic, which I think is appropriate for this application.

 

[Buford T. Justice]

My 1998 GT specifies 80W-90 in the rear end. It is the 8.8" rear end. I need to change it soon and I plan to use Mobil 1 75W-90 in it. I run Mobil 1 EP 5W-30 in my engine.

 

[Axe Man]

Want more inconsistency? Buddy bought an '05 convertible with the 4.0L V-6. That engine specs 5W-30.

 

[Schmoe]

I guess they figure the need a stronger oil since the V6 owners whould have wished for a V8 and drive the crap out of them to stay up with a V8.

 

[427Z06]

The 4.0L V6 is a derivative of the German Cologne V6 designed more than 3 decades ago. Old German design = thicker oil, quite often.

 

[mechtech]

I speak a little German - 5W-20 = 20W-50!

 

[Papa Bear]

That's converted to sea level. P.B.