After I rebuilt the 350 in my '62 one ton,I ran it for abouty a thousand miles on regular oil,then changed over to synthetic. I drove on that for about 4 months and it didn't use even a half quart. then I drove to Reno (about 300 miles) and in that distance it used 4-1/2 quarts! Any ideas why if didn't use oil for local driving and driving less than 50 miles each way on the freeway,but when I drove a little more distance my truck started gulping the expensive oil?
Speed
