5.4 Ltr which type of oil?

[Dex]

I bought a used 04 F250 with the 5.4 ltr (gas burner).
When it was traded, the dealership put 15w-40 MC syn/blend oil in it and state 5,000 miles between changes.
The manual reads to use MC 5w-20.
Was curious what type is used by those pulling TTs.
I will just be pulling the ultralite. Nothing too heavy, just the wind drag with the overdrive out and turning around 2800/3000 RPM at around 65/70 MPH.
I've done lots of searches and have read lots of confusing info.

[Dex]

I bought a used 04 F250 with the 5.4 ltr (gas burner).
When it was traded, the dealership put 15w-40 MC syn/blend oil in it and state 5,000 miles between changes.
The manual reads to use MC 5w-20.
Was curious what type is used by those pulling TTs.
I will just be pulling the ultralite. Nothing too heavy, just the wind drag with the overdrive out and turning around 2800/3000 RPM at around 65/70 MPH.
I've done lots of searches and have read lots of confusing info.

[JimmyDee]

Keep in mind that the light weight oil is so the manufacturer can get an additional 1/8 of a mile per gal mileage on their fleet. You may not need the 15-40, it is used for diesel engines but it sure will not hurt the 5.4. I probably would use 10-40 in the summer and 10-30 in the winter. Usually, within limits, a higher viscosity oil will give you better protection for heavier service.
Jim

[rclarke]

5w-20 is the proper oil for all seasons. I have seen Ford modular engines blow an oil filter when using 15-40. A blown oil filter will cause catastrophic engine failure before you can shut it down. Ford will not warrenty a blown motor with the wrong oil in it.

[Dex]

Thanks! I wonder if the guy misunderstood me and thought I had a diesel.
I'm going to put 5w-20 back in.
Oh BTW, it has 45,000 miles and had only a 3 month/3000 mile warranty.
The dealership wanted $2,400 for an extended warranty.

[Ray,IN]

Dex read your owners manual closely about oil designated for different temperatures,and towing. The 0W and 5W oils are engineered for fuel mileage, not extreme duty use, any towing is considered by manufacturers extreme duty.

[Paul Heuvelhorst]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Dex:
I bought a used 04 F250 with the 5.4 ltr (gas burner)... the dealership put 15w-40 MC syn/blend oil in it and state 5,000 miles between changes... The manual reads to use MC 5w-20. </div></BLOCKQUOTE>
Dex, see a description of our rig below. I have used 5w20 in my truck since we bought it new 87,000 miles ago, with oil changes every 5K, and all other service as recommended in the maintenance manual. We have snow about 6 months of the year, temps dropping into the teens. Summers, including travel, temps can reach 100+, although while home it rarely goes above 85. We do not change the oil viscosity due to the change of seasons or temperatures.

Our TT weighs between 5500-6000 lbs when loaded, and our truck continues to purr at 57-58 mph at 1750 rpm when on level ground w/OD. The only time the rpm goes higher is on accelleration and driving in the mountains (where we live). The truck uses no oil between changes. We are absolutely pleased with its performance and would not change the manufacturers recommendations.

[Dex]

Though the oil only had about 2500 miles on it.
I changed it and added back the MC syn. blend 5w-20 like the manual suggests.
The oil that I drained was thin, so I think it might have been 5w-20 after all.
Thanks for all of the replies!

[JimmyDee]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Thanks! I wonder if the guy misunderstood me and thought I had a diesel.
I'm going to put 5w-20 back in. </div></BLOCKQUOTE>
No misunderstanding. I firmly believe you could use the heavier oil with no harm and may even be better for the engine. I've never used and don't have any friends that change their own oil that use the 5-20 oil. I'll stay with my original post. I would say if you were using a pure, PAO synthetic 5-20, you would be fine but its your choice.
BTW, the only filter I ever heard of that let go was in an old Ford 390 truck engine and it was because there was a problem with the oil pump. 30-35 years ago and it had over 100k on it.
I would never use the 15-40 in the winter here in Michigan and don't use it in my diesel either. I use Delvac 5-40 in the diesel.
Jim