Would there be any harm in using a 5W-40 Mobil synthetic (Delvac-1) in a 5.4 triton, when the manual specifies 5W-30? This is a heavy duty extended drain truck diesel/gas oil that is SAE rated for all current gasoline engines.

 

There have been posts about a lady who changed her oil every 3,000 w/10w-30 and her oil pump failed. Ford wouldn't warranty because the manual specifies 5w-30!!

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Red 99.5 Lightning,#0975,Born 5/6/99...Adopted 5/27/99 (UN) SuperChipped (Temporarily I hope)

 

check out the thread on Moter Oil Survey-Which oil do you use, or something to that effect. Because of that thread, I posted one called: Moter Oil Survey. I have now started having my oil tested and my first results are there. I use reg oil 10W30

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers & Clarion APA5240amp, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
Better Built Stainless nerf bars

 

Most common denominator seems to be 10-30 if that helps. Alot of lean towards synthetic, especially Mobil 1, it seems to me. Ford would have one hellacious time blowing me off for regularly changing (3000 mi.) with top shelf 10-30.

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Ben Mc.----'99 XLT 5.4 SC SB ORP Dk. Red/Dk. Grey----Fact. Cab Steps/Tonneau/Slider----Straight Duals, Superchip, Airaid/KN (non-sag), Ungo Autostart/Keyless Remote, Prime Designs Air/Bug Deflector, Weathertech Wind/Rain Deflecters----PPI 4240 Amp,McIntosh 6x9's w/crossovers front, Polk DB 5.25's rear---Tuessssdayyyy Affffternoooooon----gotta love it!