I know the owner's manual specifies 5W20 wt oil but in my opinion this is more for gas milage rather than the prevention of actual wear and tear. I'm about to move to AZ this summer with 110+ degree temps and would rather use a 5W30 wt synthetic oil than 5W20.

I'm not the expert on engine oiling and oil viscosity but won't this provide better lubrication and protection than thinner 20wt oil at high engine heat levels? Will using 5W30 oil cause any potential engine damage? Any opinions on this matter would be appreciated.

Thanks,

Boss Hogg
2004 Ford F150 FX4 4X4 S/C

 

no it should not. It might make the truck a bit harder to start cold, and gas mileage might decrease slightly, but other than that it shouldnt. My 97 tbird recommends 5w30, but ive run 10w30 a few times, i didnt experience any problems with it at all.

 

Welcome Boss Hog!

The 5W/20 discussion has been going on since the 2001 models arrived. From what I've come to understand from the post here and speaking to a Ford rep is that the 5W/20 is a very very good oil and should be used.

Below are the points my Ford rep told me...

- For CAFE fuel economy only? He says no. The slight increase in fuel economy was just a side benefit, but the engine tolerances of these modular engines benefited from the lighter oil. He pointed to the fact that Ford not only recommends this oil for new F150s, but the whole range of modular engines down to the 1997 model year. Why would Ford risk hurting it's earlier engines (and its reputation) on older cars and trucks that CAFE numbers do not apply to?

- He also stated that tolerances of 1997 - current engines haven't changed, but that 5W/20 actually improved lubrication for all modular engines, including those spec for 5W/30 (2000 and older). By the way, just about all Ford dealers are putting in 5W/20 in every F150 during oil changes, including pre-2001 models.

As a side note, almost all Honda cars run 5W/20, and since they are already known for fuel efficient and reliable engines, why would they risk running 5W/20? They really don't need the CAFE numbers, plus they would not risk the reputation on engine reliabity they are known for.

If you research previous post on 5W/20 (and there are plenty), you will see how views have changed from skepticism to acceptance on this oil. Some members on this board have mentioned some oil analysis test where the Motorcraft 5W/20 was shown to be very good even compared to full synthetics, and at a cost of $1.33 at Walmart, not too shabby.

 

Although many people have many opionions... I'll state mine since the question was asked.

I am a Prototype Mechanic for Ford Motor Company and I would recommend using the 5W-20 in any modular engine. At work I have personally torn down many 4.6L and 5.4L durability test engines that had over 100k miles on them and I am impressed with the wear.

Granted I have not personally seen any of the modulars w/ over 100k miles that have run other viscosity oils, but I will be happy if the engine in my own truck wears like the ones I've seen at work that have run 5W-20 since built.

Running _W-30 or higher may starve the top end of your engine of oil. These modulars are running with tight tolerances and the higher viscosity oils may deprive the top end on demand... which is when you want the best lubrication possible.

After saying that... I'll mention that I was not real happy when the moduar engines went into production. I was a big 5.0L & 5.8L fan, but i'm coming around to the modulars. Honestly the best to date in my opionion are the 5.4 3V and the 4.6 4V.

 

I currently run 5W-30 Mobil1. I use my engine to it's fullest ability and want the protection of that oil.

Ford obviously needs to use the thinner oil to meet federal mileage requirements, and may have because of that, designed engines to accomodate thinner oil. I'm not trying to imply anything by this to you guys in particular. My own brother works for Ford as well at the Rouge plant in Detroit. I've had lots of talks with him about various Ford issues and he tends to back the company, which is fine, but also biased.

I would really like to see an unbiased, independent study of this to get the real story.

I would also love to squeeze out 250K miles from this engine before I need to replace it.

 

whats the recommened oil change mileage on the new 04's? and also id 0w-20 bad to use or should i just stick to 5w-20 in the 4.6? i wanted to try synthetics, but the the topic of increased gas mileage arose. what makes what increase mileage?

 

I’m a new convert to the Ford this year. I questioned the thin oil too. A friend of mine, who owns an auto shop, is a die hard Ford truck man and keeps up to date on all aspects.
He says the thin oil protects better because it flows faster. Makes sense to me.

 

I'd run the 5w20 on a 5.4L 3v (or if you want synthetic run 0W20) as I know of no reason it doesn't protect from heat and it protects better in cold. Also I'd be nervous going heavier on a 5.4L 3v as I belive the variable cam timing uses engine oil to activate.

 

Probably should have done a search before posting. I've heard this arguement of lower weight versus higher weight oils before in the mustang community (traded in a Mustang GT on my truck). I just wanted to hear the truck guys opinion.

The only thing that confuses me is if this weight of oil (5w20) does improve oiling and lubrication then why on the limited edition Cobra-R with the 4V 5.4 DOHC does Ford recommend 15w50 weight synthetic oil. Is it primarily due to the fact that that engine has a forged bottom end with looser piston to cylinder tolerances?

 

what's the question???!!!

Ford says use 5w20... so use it!

They made a great truck, i kinda think they know what they are doing.

 

I just switch to Mobil 1 0W20 it cumply with Fordīs specs as stated in the User Manual

Also the can of Mobil 1 reffer to Ford Specs.

I think is the best oil after AMSOIL for my truck. As Oscar said, If Ford choose that oil grade USE IT!

 

I'm using whatever brand is on sale, whereever I can find it, but I make sure I ALWAYS use 5W-20. Guy at the service desk of the local Ford dealer here says it doesn't matter if it's semi-synthetic or not. I change the oil and filter myself every 5000 miles.

 

Is everyone using 5W20 in their trucks? I am not. I displaced the Motorcraft branded Conoco 5W20 semi-syn in my 04 F150 with AMSOIL 0W30. But then, I am an AMSOIL dealer. However, I was using AMSOIL before I became a dealer.

Screwdrive

 

hey Screwdrive: any way to get me some of that Amsoil in 0w-20 synthetic for my 4.6?

 

Oil topics are like Ford/Chevy, etc, etc.. Everyone has an opinion. From what I've read, Ford's 5w20 is a semi synthetic and is a very good oil for the price (can be bought anywhere from $1.85 up).. The 5W20 and 0W20 oil's are almost 30 weights and shear very little. A 5W30 dino oil will shear to a 20 weight very quickly. I am running 0W20 Mobil 1 and am changing oil and filter every 6,000 miles. You will see more and more manufacturer's specing the lower weight oils.