Motor oil question(s) 1999 Winnie 31C

live2hunt · 05-14-2023, 08:11 AM

1999 Winnie 31C w/ Ford chassis / V10.
I'm getting mixed responses to "how many miles between oil changes in this engine". Also, some responses say to change it every 6 moths or so. It does sit for long periods of time . . . but change the oil?
ALSO:Can I switch to synthetic in this old dog? Has 71,500 miles!

**creativepart** · 05-14-2023, 09:50 AM

Like any other engine, you have an Owner's Manual that gives the oil change interval.

My Ford v10 (Ford F53) calls for every 8,000 mi. But I change mine every 5,000 mi or around there. I use full synthetic and have since new. But I'm not sure with an old engine. I would change yearly if I didn't put 5,000 miles on it in a year. But I put 12,000 mi a year on my RV.

Here's a link to the 1999 owner's manuals but it's likely that your 1999 motorhome has a 1998 chassis. Probably not much changed between '98 and '99.

https://www.ford.com/support/vehicle...owner-manuals/

**Eagle5** · 05-14-2023, 09:55 AM

Hi Live2Hunt,
The six-month oil-change interval is a recommendation which comes from extreme short-distance trips. We used to see that years ago in a Phillips 66 station in which I used to work. Vehicles which were driven one mile and then shut-off would generate slug which would show-up on the dip-stick. The water made in combustion would end-up in the motor oil, and because the engine wouldn't get hot enough, the water wouldn't evaporate out of the oil.
If you take trips long enough where the oil fully heats-up, you do not need to change at 6-month intervals. Plus, modern motor oils are much better at resisting the formation of sludge.
I would recommend that you change to Mobil 1 0W-40 and use 5,000 mile change intervals.
Thanks, Eagle5

Ray,IN · 05-14-2023, 12:04 PM

Did 0W40 oil even exist in 1999?

According to this blog The Ford V10 engine holds 7 qts. of 5W30 synthetic oil. Cold climates call in 5W20 synthetic oil.

**Eagle5** · 05-14-2023, 03:20 PM

Hi Ray,
The 0W-40 was not available in 1999, but the oil is to engines as type O-Negative blood is to people. I run it in everything I own.
In 1999, the recommended viscosity for the V10 was 5W-30, so 0W-40 is not as gluey when cold, and is thicker at high temperature for better protection. This flattened viscosity curve is especially good for an older engine.
I have a prior Thread on this subject.
Thanks, Eagle5

live2hunt · 05-14-2023, 05:56 PM

See I'm a little old school and not sure switching to synth would be "healthy" for the engine. I also hear that synth should produce a little better gas mileage.

**Eagle5** · 05-14-2023, 06:39 PM

Hi Live2Hunt,
All multi-viscosity oils have synthetic additives.
A lower second number on the oil will give you greater fuel economy. They actually now sell an oil which shaves the second number, such as 0W-16. Sure, you might get 0.02 MPG more; until a bearing crashes or a cam scars.
Eagle5

cthiggy · 05-14-2023, 11:46 PM

FWIW, I am 83 years old😒, owned/rode a '72 Norton 750 motorcycle, rebuilt two (2) Porsche engines, a '57 Thunderbird 312 engine, a Lycoming O-360 engine in a Grumman AA-5B Tiger plus operated a Class A RV with a CAT 3126D diesel engine over several years. Have used AMSOIL in all (except the Lycoming) over the last 30 years with no engine issues whatsoever.

It would appear a heavier WT AMSOIL would probably work well in an engine with 70K miles assuming there is no other damage or excessive wear. AMSOIL makes oils for older engines and can provide advice on this subject.
No, I don't sell AMSOIL, just a user.

The Original Equipment Manufacturer's Manuals are certainly valuable guides for their equipment. Just note their manuals are written to address a wide range of operating environments, i.e. generally from Canada to Puerto Rico and beyond. Your mileage may vary.

Three (3) of our current vehicles recommend 0-16Wt oils which is probably adequate for most climates. However, we live in Florida and rarely travel North of the Mason Dixon line and never have to worry about engine starts below 50 degrees F. So I usually bump the engine oil viscosity up a couple of notches for a little extra temperature protection. Protecting the engine is more valuable to me than increasing the MPG by one (1) mile.

To each, his own..........,
cthiggy

live2hunt · 05-15-2023, 07:10 AM

Well here in Cheyoming . . . it gets below 50 degrees . . . a lot! But we only drive the RV when it's above 60 - 70 degrees! So many opposing opinions on converting to synthetic oils. Both on line and face to face with mechanics and the like. We're planning an upcoming trip of almost 4,000 miles to Georgia in July and I'm leaning towards converting to synth. Thanks for all your responses . . .

Bobn1957 · 05-21-2023, 09:26 PM

The problem with switching to synthetic is you might see some oil leaks appear, things like main seals!

DryCreek · 05-23-2023, 06:37 PM

Quote:

Originally Posted by cthiggy

a Lycoming O-360 engine in a Grumman AA-5B Tiger Have used AMSOIL in all (except the Lycoming) over the last 30 years

AeroShell is like glue. Well, except during climbout at Vy on a summer day.

live2hunt · 05-23-2023, 07:05 PM

OK . . . I think I'm going to go with my gut here and go with the Motorcraft synth blend and Motorcraft filter like I do/did my other Fords. Thanks all . . .