Changing from semi-synth to full-synth--anything to look out for?

[mikes2017gt]

After my car nearly fell off the 4-post lift and got greasy-handprints all over it too, I've decided the dealer will no longer perform regular maintenance on my ride. I bought a service plan for it, so that's why they were doing it.

For my first DIY oil change on this car (not my first EVER, LOL!) I'm moving to Mobil1 full-synth (stock 5W-20 weight) and will be using the standard Motorcraft 500S oil filter.

Is there anything I need to look out for such as changing the oil AGAIN, sooner, due to the engine needing to be fully flushed of any residual semi-synth that will inevitably left in there after the first fill w/full-synth? My car has 29K miles on it, if that helps.

Thanks!

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[Grimace427]

...due to the engine needing to be fully flushed of any residual semi-synth that will inevitably left in there after the first fill w/full-synth?

There is no reason to think this. Just change the oil to whatever you wish when the regular time comes to change the oil.

 

[Deleted member 35786]

There is no reason to think this. Just change the oil to whatever you wish when the regular time comes to change the oil.

^^ Yep, most modern oils are compatible so change the oil and press on.

 

[offroadkarter]

My only suggestion would be to use 5W30 instead of 5W20, Ford only moved to 5W20 in the late 90's to meet CAFE Fleet MPG averages. Ford Racing still suggests 5W30

 

[mikes2017gt]

Thanks guys. I am the classic over-thinker...I worry about all the angles...even the imaginary ones. LOL! BTW, nice sig pic, offroadkarter!

 

[alanpv]

FWIW, a number of people who had BBQ tick on M1 EP cured it by switching to Pennzoil Ultra Platinum 5w20.

On a semi-related note, my car is currently at a dealer getting the heated/cooled seats fixed under warranty and I’ve been worried everyday since I dropped it off..

 

[Kinjirra]

funny this old tale about switching to synthetic is still floating around... You could switch back and forth between that and dino oil every change and it wouldn't cause any issues. x2 on the suggestion to switch to a 5w-30 though.

 

[mikes2017gt]

Thank you for the suggestions to switch to 5w-30. I'm sure it's working great for a lot of folks, but I'm sticking with what's stamped on the oil fill cap and in the manual, just in case. I scanned my receipts from buying the Mobil1 and the Motorcraft filters so I have a record that I'm using what the manufacturer recommends.

 

[kluke15]

in the manual it says 5-30 is an additional optional oil weight

 

[Deleted member 35786]

in the manual it says 5-30 is an additional optional oil weight

See Pg 288
Show me where it says 5W-30 in the manual for the 5.0?
http://cdn.dealereprocess.com/cdn/servicemanuals/ford/2017-mustang.pdf
http://www.fordservicecontent.com/F...g-Owner-Manual-version-1_om_EN-US_04_2016.pdf



Specifications

Materials
Name Specification
Recommended motor oil (U.S.): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

XO-5W20-QSP
Recommended motor oil (Canada): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

CXO-5W20-LSP12
Recommended motor oil (Mexico): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

MXO-5W20-QSP
Optional motor oil (U.S. and Mexico): WSS-M2C945-A

Motorcraft® SAE 5W-20 Full Synthetic Motor Oil

XO-5W20-QFS
Optional motor oil (Canada): WSS-M2C945-A

 

[alanpv]

See Pg 288
Show me where it says 5W-30 in the manual for the 5.0?
http://cdn.dealereprocess.com/cdn/servicemanuals/ford/2017-mustang.pdf
http://www.fordservicecontent.com/F...g-Owner-Manual-version-1_om_EN-US_04_2016.pdf



Specifications

Materials
Name Specification
Recommended motor oil (U.S.): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

XO-5W20-QSP
Recommended motor oil (Canada): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

CXO-5W20-LSP12
Recommended motor oil (Mexico): WSS-M2C945-A
Motorcraft® SAE 5W-20 Premium Synthetic Blend Motor
Oil

MXO-5W20-QSP
Optional motor oil (U.S. and Mexico): WSS-M2C945-A

Motorcraft® SAE 5W-20 Full Synthetic Motor Oil

XO-5W20-QFS
Optional motor oil (Canada): WSS-M2C945-A

The 18+ manual states that 5W-30 can be used on the track and refilled with 5W-20 after the session lol.

Also, 5W-30 is spec’d for the Aussie S550s.

 

[Kinjirra]

Also, 5W-30 is spec’d for the Aussie S550s.

Everyone knows you cant compare Aussie oil to everyone else...its spin of the earth in relations to the distance to the magnetic southern pole offsets the 5w-30 into really a 5w-20...also you cant use castrol magnatec anywhere since it will gum up your exhaust ports due to the extra magnetism.

 

[kluke15]

The 18+ manual states that 5W-30 can be used on the track and refilled with 5W-20 after the session lol.

Also, 5W-30 is spec’d for the Aussie S550s.

in my owners manual it said 5-30 was an additional option under the 5.0 oil section. i can check tomorrow for a picture if you want

 

[Deleted member 35786]

in my owners manual it said 5-30 was an additional option under the 5.0 oil section. i can check tomorrow for a picture if you want

Keep in mind the OP is driving 17 GT, not an 18 nor has PP according to his signature. I also drive a 17 GT and nowhere in the manual it says to use 5w-30 as an alternate... Get your facts straight.
As for the Aussies... well everything is backwards down under.. hehe

 

[kluke15]

Keep in mind the OP is driving 17 GT, not an 18 nor has PP according to his signature. I also drive a 17 GT and nowhere in the manual it says to use 5w-30 as an alternate... Get your facts straight.
As for the Aussies... well everything is backwards down under.. hehe

My bad, you are correct. I misread it under the ecoboost section. Been awhile since ive read that section specifically.

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