Half full synth, half full synth HM new truck

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Jan 11, 2018
Hello All, Long time lurker here, and couldn't find any related posts, so I figured it was time to sign up and join the community. I hope I'm posting this in the right place! Here is the run down: I just pulled the trigger on a new 2017 f150 XLT FX4 5.0L. I broke the truck in as recommended, took it on a 1200 mile road trip, have been commuting in it daily. (~45 mile round trip) I have about 3500 miles on it, it has been running great. I was told by a friend that I should go ahead and get factory oil out of the truck and change filter. I figured it couldn't hurt so I bought a new OEM motorcraft filter and decided on Penzoil Platinum Full Synthetic 5w20 as recommended by Ford/ the community. I went to buy some oil at w-mart but all they had left was one 5Qt of the regular full synth. I looked up and they had plenty of the PP High Mileage 5Qt. From what I have read on this forum this just means it has a better "detergent package." So I went ahead and pulled the trigger on buying one of each, 5Qt PP full synth, 5Qt PP full synth HM. I wouldnt think there would be a problem mixing the two, so I did.. the truck has been running great. It seems like every fill up I am getting 0.1MPG better mileage. I attribute this to further engine break in, not the oil...and I really could care less about mileage anyway.. just and observation. Are there any negative effect by mixing the two? the truck holds ~8L of oil, I use the full 5Qt of the PP Full Synth, and about 3Qt of the PP FS HM. Maybe I am just driving myself crazy? I'd love to hear what the community has to say. Thanks, Taylor p.s. Please forgive any spelling and grammar mistakes... I typed this rather quickly.
Hi Taylor, I think the "magic" to HM formulations is seal conditioners, but I'm sure you're absolutely fine with your mix no matter what. Congrats on the new truck and enjoy!
I wouldn’t do it. Take the HM oil back and exchange it for another brand 5W20 synthetic or even Motorcraft syn blend.
Well, first off welcome to the asylum! Soon we’ll have you doing 15000 mile trans oil changes! laugh I wouldn’t worry about your choice, it’s temporary as you’ll probably change it early as well. Nice truck! Easy to love F150s!
You will be more than fine. There is no harm what so ever. Congrats on the new truck and enjoy the site.
I’m generally not a fan of mixing but in your case using the same brand it should be fine. Welcome and congrats on your new Ford.
Originally Posted By: MParr
I wouldn’t do it. Take the HM oil back and exchange it for another brand 5W20 synthetic or even Motorcraft syn blend.
That truck will likely explode any second now!
Congrats on new truck! Personally, I would have put in non HM oil in a brand new truck, but I highly doubt it will affect your truck negatively. No worries
+1 to what redhat stated. I think blending within one brand is certainly just fine. Pennzoil with Pennzoil or Mobil with Mobil etc etc... Additive package very likely the exact same for the two oils being put together. Sometimes there are differences but not often. Now if one were to mix say Mobil Super and Mobil Special... There would be a difference.. Mobil super uses a bit of titanium and sodium and calcium. Whereas Mobil Special uses high calcium and a decent bit of molybdenum and no sodium and no titanium. But would that truly matter if mixing them together?? Not really at the end of the day. One thing of note about mixing... If one is in an area where the low temps are going to be pushing the W (winter rating) rating very hard.... Mixing different W's like say a 10w and 0w may not be the greatest idea in the world. If one is truly pushing the cold performance due to very, very low temps. One thing to keep in mind is that one can "inadvertantly" mix oils when changing their oil from say Pennzoil Platinum to say Mobil 1. There will be some of the Pennzoil Platinum left behind no matter what you do... Even if left to drip down over night. There are place where the left over oil just can't evacuate from. So, in all reality almost everyone has mixed oils at some point.
No harm done at all. I suspect that in the case of any 5W-20 grade oil, the primary difference between the two is probably in the labeling. It's not as though you've mixed two really incompatible oils. Nice choice with the 5.0, incidentally. No turbo or DI nonsense.
Great info all, now I can go to sleep tonight and not have it in the back of my mind! I'm not a fan of the eco engines either, my two requirements for the truck are 5.0 coyote and 36 gallln tank. Great feeling when you fill up and it says "682 miles until empty" Love the truck, basically a lariat with "cloth" seats.. although they feel more like high gauge braided wire. Much better than the old style cloth. Anyway, thank y'all again for chiming in. Needless to say, next oil change I will not be mixing the oils. Regards, Taylor
Nothing to worry about. After each change you will have about a quart of "old" oil and I suspect the majority of vehicle owners change brands every couple of OCI's. With immeasurable ill effects.
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