Originally Posted By: SilverFusion2010
After some more research I am firmly in the 10w-30 camp UNLESS you have temps cold enough that 5w is NEEDED.
I'm sure each engine has a "goldilocks" viscosity where wear protection and mpg live in harmony. Finding that is going to be a matter of trial and error with UOA.
For my particular case I have a 3.0L V6 that is GDI. 5w-20 was specified by ford without any dimensional or clearance changes to the engine, which was originally spec for 5w-30. Not knowing about fuel dilution with GDI engines, I ran 5w-20 out to 7500 mi, which is regular service interval recommended by OM. I think this caused excess wear because it started drinking oil around the 100k mark. Switching to 5w-30 helped slow it down but didn't solve it completely. Now I'm monitoring most recent fill of M1 HM 10w-30 which has viscosity just shy of a 40. I've also replaced the PCV valve to take that out of the equation.
Now can I prove that running 5w-20 hurt the engine? Nope. But I suspect fuel dilution was doing a number on the 20 and it was too thin to protect adequately by 3k or so. Had I run a good 10w-30 from the beginning of the engine's life I think the motor would be in better shape. Can I prove this? Nope. But my logic and reasoning make sense to me, and I'm going to do a UOA around 5k to see what is going on so I have some hard data.
A lower noack should help consumption caused by oil getting past the rings. A 10w-30 is going to resist heat better than an oil loaded with VII. Ditto for shearing down in grade. Ditto for dealing with fuel dilution because they start thicker.
The only downside I see for 10w-30 is a little mpg hit during warm-up, and possibly some slow cold cranking. And I mean really cold, below 0f.
Of course if you're in the thinner is better camp your opinion is going to differ from mine.
Your 2010 Fusion 3.0L V-6 DOES NOT HAVE GDI.
It is MPFI, no Ford V-6 of that era had GDI.
After some more research I am firmly in the 10w-30 camp UNLESS you have temps cold enough that 5w is NEEDED.
I'm sure each engine has a "goldilocks" viscosity where wear protection and mpg live in harmony. Finding that is going to be a matter of trial and error with UOA.
For my particular case I have a 3.0L V6 that is GDI. 5w-20 was specified by ford without any dimensional or clearance changes to the engine, which was originally spec for 5w-30. Not knowing about fuel dilution with GDI engines, I ran 5w-20 out to 7500 mi, which is regular service interval recommended by OM. I think this caused excess wear because it started drinking oil around the 100k mark. Switching to 5w-30 helped slow it down but didn't solve it completely. Now I'm monitoring most recent fill of M1 HM 10w-30 which has viscosity just shy of a 40. I've also replaced the PCV valve to take that out of the equation.
Now can I prove that running 5w-20 hurt the engine? Nope. But I suspect fuel dilution was doing a number on the 20 and it was too thin to protect adequately by 3k or so. Had I run a good 10w-30 from the beginning of the engine's life I think the motor would be in better shape. Can I prove this? Nope. But my logic and reasoning make sense to me, and I'm going to do a UOA around 5k to see what is going on so I have some hard data.
A lower noack should help consumption caused by oil getting past the rings. A 10w-30 is going to resist heat better than an oil loaded with VII. Ditto for shearing down in grade. Ditto for dealing with fuel dilution because they start thicker.
The only downside I see for 10w-30 is a little mpg hit during warm-up, and possibly some slow cold cranking. And I mean really cold, below 0f.
Of course if you're in the thinner is better camp your opinion is going to differ from mine.
Your 2010 Fusion 3.0L V-6 DOES NOT HAVE GDI.
It is MPFI, no Ford V-6 of that era had GDI.
