08-28-2013, 05:12 PM
Dodge Ram Forum Senior Member
Join Date: Dec 2009
Location: San Diego East County, Ca
Vehicle: 2009 Dodge Ram 1500 2X4
Trim Level: quad cab SLT
Color: sunburst orange pearl
Rep Power: 21
My '09 5.7L Ram Owners Manual reads
3,000 miles, but they are referring to Conventional 5w 20 Motor Oil
i use Synthetic 5w 20 & i like to run it to 5,000 miles
If you look at the year or 2 newer Dodge 5.7L manual, (identical engine), it reads 5,000 or 6,000 miles between changes, again that is for Conventional Oil
Now the 2013s say to use the same oil & i believe it reads 8,000 miles between changes & it is still the same engine block
in reference to AIRCRAFT engines
they don't use Automotive Engine Oil, it has too many or the wrong additives
when a Aircraft Engine fails for any reason, they can't just pull over to the side of the road & call a tow service
our auto motor oil would make the Carbon Deposits GLOW & cause pre_ignition & premature wear
taken from an Aviation website
These additives are designed to help prevent carbon deposits in the combustion chambers that will glow under normal operation.
That's the ashless part.
The dispersant are the detergents, that help suspend contaminants in the oil, so they may be swept out at oil change time.
It is my understanding that extended use of automotive oils in A/C engines may cause a build up of carbon deposits in the combustion chambers that are prone to glowing under heat, like a glow plug.
These glowing embers will help pre-ignition of the intake charge, and detonation symptoms may set in because of it.
Av-oils will also leave carbon deposits, but they are less prone to glowing, and less likely to cause detonation.
Ram 1500 SLT Quad cab, 5.7 HEMI(R) MDS VCT, 5 speed auto 545RFE, 3.55 differential gears, 18" Magnaflow muffler, EGR bug deflector, Bushwacker fender flares, customized Nfab nerf bars, CB radio, Autonet wi-fi router, custom soft tonneau cover, Line_X bedliner, DEBO Step, build date 10/15/08 a Wednesday