Royal Purple & Motorcraft filter 820s I believe. Pretty much have run it since day 1 when I bought the truck new and she just clicked over 66k with zero problems.

Edit: Sythetic oil will not cause a leak, but (as was already said) it will make an exisiting one worse.

 

I have used castrol syntec,mobil 1 full synthetic and motorcraft.
I would still use the full synthetic but i refuse to let my truck go over 3,000 miles on a change.So i just run motorcraft oil and filter and it seems to be fine,runs smooth and no noise so that's where i am staying.

 

I run the cheap walmart brank and im just about at 200,000 miles had it since 75000 and it runs fine.

 

what are the guys that run synthetic oils get for intervals between changes. I know that a lot of cars are going 15000 and even 25000 but can you do this with a truck???

 

It really depends on the viscosity breakdown
You can run various oils in the truck and send them off to see the breakdown. Costs like $30 I think to check it out.
I think 5k on full synthetic with mix driving is just fine.
Most mechanics will agree.

 

Mixed driving, 2500-3500 miles between changes.

I ask alot out of her, so I treat her well.

 

Amsoil. You cant go wrong.

 

I prefer Amsoil and Royal Purple myself. Anytime you bring up lubricants on forums, the inevitable always occurs, and that is someone else telling you how to spend your money. I'm not agreeing or disagreeing with it, but it always seems to happen.

1. Since you brought up the use of synthetic oil, I will assume that you have realized and accepted the fact that it does cost more than dino oil in general. Therefore, cost should not be an issue. Yet, you should always expect someone to remind you that it is pricey. It is Your decision to spend the extra $$ if you wish. I choose to do so.

2. If you fall into the realm of the 3K OCI crowd yet still want to use synthetic, then I recommend using Walmart's brand at $13.96 per 5 qt. container.

3. If your goal is to lengthen the time between OCIs using a more expensive synthetic, then you will actually save more money per year than those who use oil that costs $2.34/quart and change their oil every 3K-in general. (So long as you've shown via oil analysis that YOUR truck can handle extended oil drains on the oil you choose).

I thought about scanning my last 4 Blackstone reports and posting them just to share. 2 reports showed after 3000, and then 6000 miles using Royal Purple 5w20 in my 2005 S.crew, the TBN was 9.6 and 8.9. That is with towing 1x/week with trailer(750#) and mower(400#) about 25 miles. If the usage trend is linear, and I do not deplete the TBN by more than 1 point every 3K miles, and analysis recommends a change when TBN is about 1.5 to 2.0, then I can go quite a lot of miles on one oil. Even at 6008 miles, the report stated that "filtration is excellent." At that time I had a Mobil 1 oil filter and an Amsoil air filter. I paid $6.50/quart (cash, no tax) for the RP and $9.99 for the mobil 1 filter.

But, and this is hearsay, I've heard that TBN depletion is not linear in all vehicles. It has a steady depletion until it reaches about 4 or 5, then drops off faster, much like a gas gauge when it reaches the "half tank" mark. Regardless, even a 12K mile OCI can be achieved easily.

I think many folks get into the mindset that they just gotta change that oil because it's black. And it MUST be changed at 3K miles or the engine will break.

I'll step up and be the guinea pig. If something bad happens to my motor, I'll let you all know. If nothing happens, well, I'll keep you posted. I don't mind putting these 'snake oil' claims to the test. (Actually my brother will be the real guinea pig, he's as lazy as they get when it comes to vehicle maintenance....He put Amsoil 0w30 in his wife's van (2003 Windstar I think), and she's already gone at LEAST 23K miles on it. He hasn't even bothered to do ONE analysis. But the good news is it hasn't used any oil).

 

Engines and formulations may be different these days, but when I was selling Amsoil, we had data that showed if you could keep the oil from getting too contaminated, you could safely run synthetic to over 100k miles. This is why they came up with the bypass filtration kit. If you are using just a conventional spin-on filter, you will have to change synthetic oil due to contamination long before it breaks down.

I'm running Mobil 1 with a Wix filter right now and I plan on running it to about 10k.

 

I have always grown up around the farm using dino oils and i always have used GTX in my truck since i have owned it. But i am moving now to the city( in hte military) and i wont have access to the garage as much so im trying to see if its worth it to change to synthetic's. I know it cost more and i would use probally ams oil. I run it in my tranny and love the stuff. I dont wnat to run it though if i cant at least double the time between oil changes.

 

You should be able to safely run Amsoil with extended drain intervals with an Amsoil Ea filter. There are 3 recommended products for your engine - the 5W20XL (XLM) is good for 6 months/7500 miles, the 100% synthetic 0W20 (ASM) is good for 1 year/15000 miles, and the Series 2000 0W30 (TSO) is good for 1 year/17500 miles. These are the stated severe service intervals, I personally would not exceed these even with normal service.

 

Also keep in mind even FORD recommends a 7,500 mile interval with normal dealership oil and filter now.

 

I was thinking of switching to the 100% synthetic in my 150. Anyone blindly trusting the 15k interval? For me that is one change per year.

I am definitely thinking of changing the trans fluid to Amsoil at 30k.

 

You can trust 15k miles with premium filtration. The Amsoil Ea filter is premium with a corresponding price tag.

15K is twice what's recommended for dino - there you go. The 7500 recommendation from Ford is for normal service, not severe service. You can push the proper synthetic farther than 15k for normal service but I don't recommend it, they still put a 1 year cap on that.

I don't think Mobil 1 is as good as Amsoil, and even though the Wix is a premium filter, I don't think it's as good as an Ea. That's why I only plan on pushing the Mobil 1 to 10k. With all the driving I'm going to be doing this summer, it won't take very long to rack that up.

If your truck is still on warranty, I would not exceed Ford's recommendations with *any* oil. This only gives them an excuse to deny a warranty claim.

 

I just ordered 4 more oil filters Amsoil and the preferred customer price was $12.15. (Actually only 1 of those is for me personally).

As far as transmission fluid goes, I agree with many of the above posts regarding Amsoil. The fact is, they've been doing this a long time and they make an excellent transmission fluid.

I didn't blindly trust the 15K interval, I used a lab. I can tell you with confidence, that most any premium synthetic oil will outlast the best spin-on oil filter. It's all about good filtration. You can easily go 15K miles on the oil.

The interesting thing about my neighborhood is the large number of F150s and F250s. There's a bunch of us in the tribe so to speak. And many of us have gotten together to place orders on stuff. One other fellow up the road has a 2003 F150 and he goes 15K miles per oil change using Amsoil 0w30 and the Amsoil EA oil filter and air filter. He's never once bothered to send any out for analysis and he drives a lot. He now puts 30+K miles per year on his truck and has yet to have a problem. He's used Amsoil since he bought the truck and dumped it in during the first oil change. Last I heard, he has 135K on it or close. No problems yet. He went Amsoil all the way, front/rear lubes and transfer case, and drained his power steering fluid and refilled with the Amsoil ATF also.

Another neighbor uses the motorcraft filters and changes them every 5K religiously and tops off the oil. He uses the Penzoil synthetic stuff or Royal Purple and he changes his oil every 12K.