Guys has anybody used amsoil 5-20wXL and if so how good is it? Have been using 5-20 FULL SYNTHETIC motorcraft. It seems like the engine is a little loud and it only has 5000miles on the truck, I have always used motorcraft filters. These 5.4 or louder then the engines I have ran in the past?? Mine sounds like a lite knock at idle when the engine is hot?? I know about the cam phaser noise but this is a lite knock sound at idle, The dealer said it was normal, I have lesson to 4-5 truck and they are not as load as mine, but mine has only 5k on it and the other trucks had more miles. Maybe it is normal???

 

The XL is no better than the Motorcraft. If you are going to use Amsoil, use Signature.

 

I have recently switched to full synthetic Amsoil in my truck. I've been using Amsoil in my Harley-Davidson for some time now. With an air cooled engine the full synthetic runs about 10 to 15* cooler but I don't really know yet if there is any real benefit to using full synthetic in our trucks. I sell Amsoil so there's no reason I shouldn't at least try it.

I did notice while at the Ford dealer yesterday that the new 5.0 Mustang on the showroom floor has a "Full Synthetic Recommended" sticker on the engine.

 

I've been using the Full Syn Motorcraft also and have the same noisy idle. I ran Valvoline Ful Syn last winter and the engine didn't seem to be quite as noisy. Just bought 7 quarts of Royal Purple for the winter and am anxious to see if things quiet down a little. Nothing wrong with the Motorcraft, but even though they call it full synthetic it really isn't.
You can't go wrong with Amsoil. I've used their engine oil and gear lube for years. You should get at least 10k miles on one oil change.
Also, no need to use any other filter then a Motorcraft. They are a quality filter made by Wix, and you can't beat the price.

 

I used 0-30 in my 2004 5.4 and now use 0-20 in my 2011 5.0 signature series, good stuff

 

Nope, it's made by Purolator. Still a good filter.

If you are going to go to the trouble of using a full synthetic AND going to extended drain intervals, you might as well use a premium filter made for synthetics such as an Amsoil, Mobil 1, or K&N.

 

I would have to agree with glc. I only put about 5-8K miles on my 5.4 per year and I have run Amsoil full synthetic oil with an Amsoil filter since the original break in period, now I only change oil one time a year and have had great luck with it.

 

Is signature series amsoil API approved, It looks like the only oil that is approved is XL??

 

No. Signature oils are not API certified. If this is important to you because you don't know/understand the difference, then stick with the XL. The OE is also certified. Also like glc said, the XL is every bit as good as MC and if I wanted a certified oil for reason X, then I personally would run XL over MC.

While I'm certain many may chime in and label it as Amsoil propaganda, here's some reading for you if you'd like to educate yourself on the signature oils and API licensing. Do your own additional homework also and make an educated choice.

https://myaccount.amsoil.com/dealer/...Factor/API.pdf

Additionally, if you happen to decide to follow and not exceed the recommended change interval for whatever reason, I personally wouldn't use the signature even if the lack of a stamp doesn't scare you away. Might as well save the money and use the XL or OE.

 

Guys thanks for the input, I did go with Signature 5w-20 and a motorcraft performace filter what I have read it should be a good match (BITOG). I did contact amsoil and they told me it was the best amsoil I could use in my truck. I hope I did the right thing?

 

Why not use an Amsoil filter?? More expensive; but you're using the best, expensive oil, why go cheap on the filter? Pick one up...the difference in quality and construction is very apparent. You only did the right thing if you're going to stretch out the change intervals. If you're not, then you wasted money for no mechanical benefit. But that's all you did. Obviously the oil isn't gonna hurt anything; it's the best you could have gotten.

 

Since new,amsoil filters and 0w30 then switched to 0w20 when available,once a yr changes,ready to crack 350 k trouble free miles

 

http://www.bobistheoilguy.com/forums...Number=2222345

This is the filter I am using it seems to be a great filter.

 

I run Amsoil in my car but than again it makes 530 rwhp even though I run Amsoil in nearly everything I own. API Certified means little when talking about Amsoil or any boutique oils as it just shows that said oil company has paid API in all reality.

Glad it sounds like someone else is also knowledgeable about oils.