Just got a 99 Ford 6.8L V10 89k miles w/ Dino 10w40 Which oil?

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Nov 15, 2018
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Bloomington, IN
Greetings,
Just bought a 1999 26' RV w/ Ford 6.8L V10 Triton w/ 89K miles. The owner of the last 3 years has used Valvoline Dino 10w40 but manual says 5W30. It has 1000 miles since last change. I'm going to be taking it this summer on 5K Road trip and thinking about going to full synth and just not sure. I use Mobil One 0w20'in my 2013 Prius V and Castrol Edge 0w40 in my 2007 BMW X5 so am a fan of synthetics. I at least want to use the Motorcraft 5w30 part synth that Ford suggests rather than the Valvoline 10w40 and a quality filter w/ silicone anti-drain back valve. Also should I consider high mileage oils? There are no leaks now.

Was hoping some of you smart Folks may have some advice?
Thanks in advance!
 
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That's a big, heavy, rolling brick of a vehicle. You're going to want something much beefier than a 5w30. That being said, a Mod motor will be happy running on basically anything you decide, from dino 5w30 to synthetic 10w40.

What kind of conditions will the RV see while in use? Hills, ambient temps, loads (water, waste, passengers etc).

Might I suggest this: Valvoline Premium Blue Extreme 5w40

Premium blue gets big thumbs up around this forum, and the extra protection of running a xw40 won't hurt anything. I would use a Fram Ultra filter, it's one of the highest rated filters on this board, as well as affordable.

Does the rig have an oil cooler? I believe on the mod's it's just a sandwich cooler between the filter and block. It's more of a warmer than a cooler, but if you aren't pushing 70 through the Nevada desert in August you should be fine.

There should be a 4r100 trans backing up that motor. Solid unit, definitely install a pan with a drain plug (if not equipped, many commercial chassis were from the factory) to make drain and fill's easy. Have the spark plugs been done? I believe '99 is still within the years that had too short of spark plug threads and tend to loosen up. I would recommend having all 10 done right now if they haven't been, and make absolutely sure they're torqued to the UPDATED spec from Ford.

Let's see some pics, BTW!
 
Edge/Mobil 1 0w40, or any 5w30 syn you prefer. MotorCraft isn't worth it if you can get a full syn for the same price, its all about licensing. Being that the truck is from 99' the oil specs on it shouldn't limit your options much.
 
I'd go with the motorcraft 5w30. I used that in our Fleetwood Bounder with the same engine. Other than broken exhaust manifold studs we had no problems out of that engine. My dad has one in his pickup that he tows equipment with regularly. He uses what he has or gets from me cheap or free. And lets it go until he feels like changing it and hes had no problems out of his other than exhaust manifold studs. See a pattern here?
 
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I would use Pennzoil conventional 5w30 with a FRAM Ultra filter. After you get back put in a full syn of your choice. The Castrol Edge 0W40 would be a good choice. Happy Trails!!!
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I just bought it tonight 99 Fleetwood Jamboree 26' and haven't even picked it up yet ;-)

It will be loaded up with 4 adults and going from Midwest to CA and back via southern route. I may lease it out on RVShare too.

I hadn't heard about that Valvoline Premium Blue Extreme so many thanks for the tip. Fram Ultra sounds like the best vs the M1 one I have used.

It has new plugs and coil packs so all good there, but will
Check the torque for sure. New brakes/wheel bearings/drive shaft reconditioned/seals, 3 batteries, tires, belt, and it purrs.

Don't think there is a mod oil cooler and don't know yet much about the stock cooler.

Asked the seller about tranny fluid and he only said it looked fine, so I best be changing it. Thanks for the tip RE the pan.

It was only $14K and was completely redone inside, new roof, I mean this seller was legit and spent over $7K I parts and many many hours rehabbing it. My wife fell in love right away.

Would love to share the photos but not sure how to do it? Guess I can add to cloud and use the link?

Respectfully,
DooDah
 
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I'd go with Ford's recommendations for oil and oil filter.

I think Ford has a TSB for the 1999 F450 V10 6.8 changing the oil viscosity and how to fill it according to the dipstick.



I copied below from the Amsoil website. I cannot verify it's accuracy beyond my simple copy and paste:

VISCOSITIES:
All TEMPS....5W-20 This specification has been updated from 5W-30 to 5W-20 per a Technical Service Bulletin from the manufacturer 5W-20 is the preferred viscosity.

CAPACITIES: With filter 6 quarts EARLY MODELS: Oil level should be no higher than 1/2 inch (12 mm) below maximum on the dipstick. LATE MODELS: Oil level should be no higher than 1/8 inch (3 mm) above FULL line.
 
Wow thanks for the info. I heard about some using 5W20 and the dip sticks can be off so you end up putting in 6.5 if fill to full mark. My gut says stay with at least a 30W.
 
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That is weird to be going to a 5W20 in a 1999 monster motor. I wonder why? And then on top of that, changing the fill volume. There is some issue they are trying to address.

I'd get my butt down to the best Ford dealer in my area and talk to the service mgr or the best mechanic. Just ask parts guy who the best mechanic is while you buy an oil filter.....

You may get an answer that will override your gut. IDK???
 
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The 5w20 thing was all about CAFE and Ford trying to eek an additional .1 MPG out of their engines. Absolutely NOTHING changed with the engine itself.

My 2003 Mercury Marauder spec'd 5w20 on the cap, but it only ever got a steady diet of Amsoil 5w30. 5k changes and multi-daily redlines and she never burned a drop. Also, what was at 225k miles.
 
Originally Posted by Gebo
That is weird to be going to a 5W20 in a 1999 monster motor. I wonder why? And then on top of that, changing the fill volume. There is some issue they are trying to address.

I'd get my butt down to the best Ford dealer in my area and talk to the service mgr or the best mechanic. Just ask parts guy who the best mechanic is while you buy an oil filter.....

You may get an answer that will override your gut. IDK???


Now that's some good advice. I usually try to stay away from dealerships but you make total sense. Thanks.
 
Originally Posted by mpgo4th
I'd go with the motorcraft 5w30. I used that in our Fleetwood Bounder with the same engine. Other than broken exhaust manifold studs we had no problems out of that engine. My dad has one in his pickup that he tows equipment with regularly. He uses what he has or gets from me cheap or free. And lets it go until he feels like changing it and hes had no problems out of his other than exhaust manifold studs. See a pattern here?



This ^^^^^^^^^.

Is what I would run... A 5w30. Motorcraft is obviously a fine oil to run. Or Pennzoil, Valvoline ,Castrol etc 5w30.
 
If you're gonna be driving it in summer heat, up grades and what not..a full synthetic is what I'd go with but that's not to say there aren't some good dino's that wouldn't work either. It's just a matter of preference...

Nothing wrong with VPB but Chevron Delo XSP 400 is another good 5w40 to consider or even a heavy duty 10w30 like Delo XLE 400, both are heavy duty API SN+ lubes. If it's only going to see summertime usage, one could argue there's no need for a 5w rated oil but your call, it's not like a 5w40 VPB or Delo is gonna grenade the engine.

How's the cooling system? When was the last time it was serviced, hoses, thermostat checked? Nothing ruins a summer road trip faster than a cooling issue.
 
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I have a 2017 v10 engine in a Class C Motorhome and the oil spec is still 5W-30. You can run that or 10w-30 with no problems. If there are No leaks, I would definitely run a full synthetic oil.
Be sure he put the RIGHT spark plugs in it.
 
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