Originally Posted By: crazyoildude
They tried syn and all of them leaked so the owner is against synthetic and so am i for this application. These trucks will be in Canada where it gets really cold according to them so its important that they have good lubrication. all the trucks have well over 100,000 miles on them.
Modulars generally don't leak oil and it being conventional or synthetic would be inconsequential. Both of our Expeditions were originally run on conventional (ours for 150,000Km, or roughly 93,000 miles) then switched to synthetic. No magic leaks happened nor did magic consumption. I have had consumption over the years on certain oils, none on others, so I stick with the oil that doesn't consume (AFE 0w-30) now. Filters have predominately been Motorcraft.
Both trucks currently have north of 180,000 miles on them.
Oh, and I'm in Canada.