Oil Viscosity and the Ford V-10

[Eagle5]

Ford originally recommended the 5W-30 oil for the V-10, but changed it to 5W-20 in about 2001 to get a tenth of a mile more per gallon (a thinner oil requires less parasitic power to flow through the engine and its bearings.) Ford then changed back to the 5W-30 recommendation in 2015 because the 20 weight isn't thick enough to protect the cams and bearings on high mileage engines, or in high-heat conditions. I play it on the safe side and use 0W-40, which flows better in cold weather start-up, and provides more bearing and cam surface protection at operating temperature.
In a multi-viscosity oil, the first number represents the cranking thickness of the oil in cold winter start-up conditions, and the second represents the operational thickness of the oil at 212ºF

• A 0 winter oil at -31ºF has a viscosity of about 6200 cP
• A 5 winter oil at -20ºF has a viscosity of about 6600 cP
• A 20 weight oil at 212ºF has a viscosity of about 7.5 cSt
• A 30 weight oil at 212ºF has a viscosity of about 10.9 cSt
• A 40 weight oil at 212ºF has a viscosity of about 14.4 cSt

The viscosity units are:

• cP = Dynamic Viscosity
• cSt = Kinematic Viscosity (about 15% higher than the cP value with 30 weight oil)

Eagle5

[wyocamper]

This is 100% Oil University spot-on. The only thing I'd quibble with is "cold winter start-up conditions". Even if the ambient temp is in the 80's or 90's when you start it up in the morning, it's still "cold" in relation to the normal operating temp of 180º+ and has been sitting for hours, so the initial 0W or 5W flow characteristics are critical.

[powercat_ras]

Thanks. I sure notice how dirty the Mobil 1 oil already is at 5,000 miles when I change oil and filter on my 2015 Vista 27N. Glad Ford told us to use the shorter oil change interval on the V10 even with full synthetic oil.

[Eagle5]

Hi Randy,
I agree with the 5,000 mile change interval. The V-10 takes between six to seven quarts, and it is important to make sure you discover the total sump capacity to bring it up to full on the dip stick right after your oil change. I have talked to mechanics who have told me this 6½ quarts ±½ quart is normal for the V-10. A fully filled sump means more oil will have more volume to "hold the dirt."
I use the Mobil One 0W-40 on all my vehicles, and all at 5,000 mile change intervals.
Thanks, Eagle5

[powercat_ras]

I've always had room to put in all of the 7th quart of oil on my 2015, with the dipstick oil level not going over the top of the normal oil range hash marks. Still not down to the add mark even after 5,000 miles. It always amazes me how little oil the beast uses over 5,000 miles, even with 60,000 miles on the odometer.

[akeagle]

Originally Posted by Eagle5

Ford originally recommended the 5W-30 oil for the V-10, but changed it to 5W-20 in about 2001 to get a tenth of a mile more per gallon (a thinner oil requires less parasitic power to flow through the engine and its bearings.) Ford then changed back to the 5W-30 recommendation in 2015 because the 20 weight isn't thick enough to protect the cams and bearings on high mileage engines, or in high-heat conditions. I play it on the safe side and use 0W-40, which flows better in cold weather start-up, and provides more bearing and cam surface protection at operating temperature.
In a multi-viscosity oil, the first number represents the cranking thickness of the oil in cold winter start-up conditions, and the second represents the operational thickness of the oil at 212ºF

• A 0 winter oil at -31ºF has a viscosity of about 6200 cP
• A 5 winter oil at -20ºF has a viscosity of about 6600 cP
• A 20 weight oil at 212ºF has a viscosity of about 7.5 cSt
• A 30 weight oil at 212ºF has a viscosity of about 10.9 cSt
• A 40 weight oil at 212ºF has a viscosity of about 14.4 cSt

The viscosity units are:

• cP = Dynamic Viscosity
• cSt = Kinematic Viscosity (about 15% higher than the cP value with 30 weight oil)

Eagle5

The owner's manual of the 2015 E450 under our 2016 Minnie Winnie calls for 5W20 oil. Do you suppose the change to 5W30 occurred later in 2015?

Would there be any benefit to our Triton V-10 with about 58,000 miles to switch to the 5W30?

[powercat_ras]

> The owner's manual of the 2015 E450 under our 2016 Minnie Winnie calls for 5W20 oil. Do you suppose the change to 5W30 occurred later in 2015?

It could be that your unit was built on a older incomplete chassis. My 2015 Vista was built on a Ford F53 chassis with a 2014 Ford VIN #. You can see what year your chassis is from the Ford VIN sticker by the Winnebago serial # sticker on your unit.

[Eagle5]

Originally Posted by akeagle

Would there be any benefit to our Triton V-10 with about 58,000 miles to switch to the 5W30?

In general, the older the engine, the more the bearing clearances increase. To keep the same bearing load capacity, the viscosity of the oil needs to be increased. So yes, as an engine gets older, a thicker oil does help.
The good thing about 0W-40 is it still flows well and maintains a hydrodynamic oil film in the bearing; even in a brand-new engine. So yes, I would switch at least to a 5W-30, but for me I would just use the 0W-40.
Thanks, Eagle5

[cthiggy]

FWIW: Everybody has their own opinion about oil and politics. I have had such great experiences with Amsoil in a Norton 750 Motorcycle, a Porsche 912 and our 2017 Cambria with the big Ford engine, I will stick with that synthetic oil. Plus living in Florida where we rarely see ambient temperatures below 40 degrees F, I bump the recommended viscosity up a little to be on the safe side for when we are stuck in traffic on a 100 degree day. I never use 0-XX viscosity for anything as I am more interested in protecting the engine than 0.1 miles per gallon.

It's important to note the manufacturers are recommending oils suitable for extreme conditions from Alaska to the Sahara.

[DryCreek]

Originally Posted by akeagle

The owner's manual of the 2015 E450 under our 2016 Minnie Winnie calls for 5W20 oil. Do you suppose the change to 5W30 occurred later in 2015?

Would there be any benefit to our Triton V-10 with about 58,000 miles to switch to the 5W30?

Or, I wonder if the difference is tied to the E chassis having the two-valve engine while the F chassis has the three-valve design.

[Eagle5]

I believe all V-10 engines built before 2006 were two-valve per cylinder designs, and from 2006 & afterward were three-valve engines. In the 2006 head redesign, the number of threads engaging the spark plug increased greatly from the inadequate 3½ turns, bringing an end to the catastrophic spark plug blow-out problem. As Ford was recommending the 5W-20 from 2001 to 2014, I do not think the three-valve head was a factor in Ford's oil viscosity recommendation.
I would estimate that the penalty in fuel economy is about 0.1 mpg in going from 5W-20 to 5W-30, and another 0.1 mpg in going from 5W-30 to 0W-40 (or 5W-40.) I do not believe the Winter number of either 0 or 5 is a big factor in fuel economy, as the engine heats-up quickly and spends most of its time pumping at full operating temperature.
Eagle5

[DryCreek]

Originally Posted by Eagle5

I believe all V-10 engines built before 2006 were two-valve per cylinder designs, and from 2006 & afterward were three-valve engines.

I was under the impression that the E-series van hood and interior doghouse cutout could not support the extra deck height of the three valve engine, and instead kept the old two-valve, but with an upgraded head that had deeper spark plug thread engagement. I think that's why you see them all rated at either 305 or 310 HP rather than the usual 362 HP (downgraded in 2016 for new transmission) that was in the F-53.

[Eagle5]

Originally Posted by DryCreek

I was under the impression that the E-series van hood and interior doghouse cutout could not support the extra deck height of the three valve engine, and instead kept the old two-valve, but with an upgraded head that had deeper spark plug thread engagement. I think that's why you see them all rated at either 305 or 310 HP rather than the usual 362 HP (downgraded in 2016 for new transmission) that was in the F-53.

That does make sense; I stand corrected.
Thanks, Eagle5