Okay really dumb question, the owners manual says 7 quart capacity for oil but does it take 7 or 5 quarts when you change it? Plan on going to synthetic so I thought I would do it myself and save some money. Never changed the oil in my 06 because I got a package for free oil changes when I bought it. But I plan on keeping my 09 for several years and thought I would try synthetic to see if it truly works better.

 

I was always told not to mix oils after an engine has been used with either non synthetic or synthetic. Perhaps someone can clear this up. Never thought about it until the OP asked about doing it himself. Or do they mean dont mix the oil?

 

Definitely don't mix the oil. What I have always been told as well is that it is ok to go from regular to synthetic, but NOT ok to go from a synthetic to a regular oil. I can't give a real good explanation, other than that is what I have been told. Also, if I am not mistaken all Motorcraft 5W-20 is synthetic.
FCSD Chemicals and Lubricants

Hence, they come from the factory with synthetic oil?

 

By all means don't mix or change the oil to another brand or viscosity, after break in also i'd recomend castrol oil after seeing some engines with castrol v other brands BIG difference plus longevity of the engine.

 

Holy cow...you have an '09 Ford pickup and are trying to save a couple bucks on oil changes? I would take it to the dealer to establish some face time with the service manager and lock in the fact that you're having the regular maintenance done. My dealer used to charge $25 and do the OC in under a half hour.

In any case, no problem switching from syn to conventional and back these days. Spend some time in the motor oil forum and you'll find that this is not a problem with modern oils.

Motorcraft 5W20 is semi-syn, which happens to be a blend of synthetic and non-synthetic, and it works great. No real reason to use anything else unless you want to extend OC intervals.

George

 

Holy cow is right! Talk about a thread full of misinformation!!

YoGeorge is right. You can run any synth after dino or vise versa. It doesn't matter.

Best (safest) oil to use, honestly, is the factory fill. Motorcraft 5W-20. And yes, it's a semi-synthetic.

 

I've never seen such a gaggle of opinions on one thread, and most wrong. Monsta's right, so listen to him.

I had the same problem with my first engine in my 08 though. Book says 7qts, but the thing only took like 6 max. Maybe even 5-3/4. I buy the gallon cans of 5w20 for mine and the wifes.

 

Thanks for the up to date info. What were the problems caused by switching back and forth in the past? I just know that in the past (been a few years) I had heard several mechanics say you shouldn't switch from conventional to synthetic, but I never was told exactly why.

 

Whoops. That was supposed to read:

I had heard several mechanics say you shouldn't switch from synthetic to conventional, but I never was told exactly why.

 

I mixed oils once in my RC car fuel and they wouldnt 100% mix with each other. Made the oil almost look like it had water in it. Not sure if this is the reason but i have never mixed types since then.

Good to hear you can mix the oils though.

 

Just found this. Makes it a bit easier to understand.


Synthetic and conventional will not "mix" and synthetic creates a barrier on moving parts, that conventional cannot pass. So, too much synthetic, as in a 50/50 blend, will be like running an 8 quart system on 4 quarts, without starving the oil pump. It will break the synthetic oil down quicker... in conclusion: The correct combination will give you no problems and will yield the benefits of both conventional and synthetic. With Engine/Motor Oil, the maximum amount of synthetic recommended is 25%. Foaming will develop if more is used, and the foam will counteract with lubrication. Higher-priced synthetic blends have more synthetic and/or more friction modifiers. Synthetic Blend as mentioned earlier is not as cost efficient as adding your own bottle of full synthetic for every 3 quarts of conventional. Just make sure the weight is the same.


Additional info or FYI:

Gear Oils can be combined, but with higher regards to percentage than as with oils. I wouldn't play chemist on my vehicle, but if need be to combine, my professional advice would be that the amount of synthetic combined with gear oil would be as little as 1%, so in other words, if you are not certain what gear oil is in... say, your differentials, drain and refill and do not worry about the remainder of gear oil that is in the differential... or leave the old gear oil (unless burnt) and simply top it off with something like Lucas Oil Conditioner that is recommended for gear boxes and will interact with either conventional or synthetic.

As a whole, greases will not blend/fold unless they are of the same "base" and this is more extreme when in regards to synthetic & conventional. Bearings need to fold the grease and exchange old grease with new grease as the bearings pull the new grease in and push the old grease out. The above mentioned barrier will contain one or the other and not allow the other to fold with it. This is where it is important to know what's what. I'll use u-joints as an example here:

When purchased, if the u-joint is packed with Lithium-based grease from the factory and John Doe's 15-minute Lube pumps the u-joints with moly-based conventional, or worse, silicon-based synthetic...

... even if they say "we flushed out the old grease with the new grease", they will not be able remove 100% of the old grease without actually removing/disassembling/cleaning/repacking/reinstalling the u-joint. So, the lithium-based grease will never be refreshed with new grease; It will eventually burn up around the bearings causing the bearing surface to disintegrate and mix in with the burnt grease, ultimately leading to a more speady premature failure due to metal mixed in with the grease. Anyone who has disassembled a bad u-joint may have seen what resembled the absence of bearings + grease and nothing but graphite powder inside. The graphite powder is* the bearings and the grease was either burnt up or thrown out when the tolerances (or slack/slop) became extreme between the yoke and cup after the bearings became worn.

Furthermore:

It could be damaging to an engine to use the wrong API specification oil:


1) Engines that were meticulously engineered/designed using API SH oil (Honda motorcycles for example, but automotive is included) can prevent a higher API rating from sticking to the moving parts in areas such as the main bearings-to-crank journals. If the oil is thrown off the bearing, it is almost as anti-beneficial as no oil at all.


2) When the vehicle has a "flat tappet" style valve train. Alkyl-zinc, now replaced with the anagram "ZDP" or "ZDDP", is needed as a cushion between the camshaft and lifter. SM rated oils are only compatible with API MIL-specs for SJ & SL. Additives such as STP Oil Treatment for 4-cylinders (more ZDP than for 8-cylinders) has a lower ZDP content than the pre-1996 formula. Special Racing Oils or Motorcycle Oils commonly contain more ZDP to protect main bearings and valve train, as well as additives for break-in periods, which commonly contain so much ZDP that they are recommended to be drained at the first scheduled oil change. The break-in additives can be used in part, to give the .1% (1000ppm)- .16% (1600ppm) content as specified in your owner's manual. Too much for too long can cause sludge, so the 41600ppm+ in say 1pt of the additive, even if reduced by means of diluting with 8 quarts of oil, resulting in a content of a 2600ppm. ZDP/ZDDP was lowered by the SAE/API to extend the life of catalytic converters. If your vehicle did not come equipped with one, the need for lowed ZDP/ZDDP does not apply to your vehicle and the need for more ZDP/ZDDP most likely does... but will not hurt anything otherwise.









Castrol Edge ® Motor Oil
Watch Castrol's Commercial from the Super Bowl.
CastrolEdgeUSA.com

 

I had the same problem with my first engine in my 08 though. Book says 7qts, but the thing only took like 6 max. Maybe even 5-3/4. I buy the gallon cans of 5w20 for mine and the wifes.[/QUOTE]

Thank you this is the info I needed and yes it does sound a little ridiculous to try and save a buck when I own a 40K$ truck, but thats how I can afford a 40K$ truck because I watched my pennies. Once again thanks for the info.

 

In the early days of synthetics, they had ingredients in them that would soften the seals and gaskets in an engine, and when replaced with conventional oil, the seals would harden and shrink and oil would leak out. Oil formulations have been changed so this no longer happens.

George

 

My 04 5.4L 3V takes 7 qts with a filter change brings it dead level up to the max. line which is where I keep it no issues

 

Check the owner's manual. It will probably say something like oil fill capacity: X quarts and then in the footnotes it might say X + 1 quart with filter change. Just read the manual very carefully.

A great site for oil information: Welcome

Tons and tons of information on oils, used oil analysis, transmission fluids, etc., etc. It will dispell the myth about going from syn to dino and vise versa.