Originally Posted By: SilverFusion2010
After some more research I am firmly in the 10w30 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 used oil analysis.
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 5w30. 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 5w30 helped slow it down but didn't solve it completely. Now I'm monitoring most recent fill of Mobil 1 High Mileage 10w30 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 10w30 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 used oil analysis 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 10w30 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 10w30 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 10w30 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 used oil analysis.
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 5w30. 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 5w30 helped slow it down but didn't solve it completely. Now I'm monitoring most recent fill of Mobil 1 High Mileage 10w30 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 10w30 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 used oil analysis 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 10w30 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 10w30 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.
