I have a F150 with 5.4 Triton engine, 2008, 4WD super crew. about 210,000 miles. The manual says 5w 20 weight. At about75,000 I switched over to Amsoil 10w 30w, full synthetic. Motor runs great by the way. I live in the south where July and August it is 95 degrees and 95% humidity. At the boat ramp with a 3000 lb boat in tow, hood closed and 30 minutes, AT IDLE to get the boat launched. Everything, temp, etc is in max range I suspect. The engine has been using oil about one quart between 5000 TO 7500 mile changes. but exhaust pipes seem pretty normal, grey in color. AS it uses oil in the summer. can I add 10w 40w maybe 1/4 quart up to the full mark or 1/2 quart without any damage to the engine? I have read 100 articles saying use what the manf says. the owner should use. Personally my feeling is this light weight oil the motor will wear out sooner. They are in the business to sell vehicles, not help u get 300,000 plus out of them. I have used Marvel Mystery oil in the gas since 25,000 miles when I bought it, EVERY FILL UP! VERY GOOD STUFF! Over 200,000 miles the engine clearances are not like new, to say the least! Bye the way, I have taken your advice about automotive lacquer thinner to use in the tank to clean the cataytic converter. IT WORKS AND YOU ARE ON THE MONEY! STILL HAVE THE ORIGINAL ONE ON THE TRUCK. ALSO UR ADVICE ON CHANGING THE TRANSMISSION FLUID.
TKS,
BB
Never use lacquer thinner. That video was 11 years ago. Use a designated CAT cleaner. Use the weight oil recommended by the mfg for the temperature you're operating in.
The engine is probably using oil because you changed the oil weight and it took a 140k miles worth of driving to wear it out to the point where it starts using oil.
Switch back to the manufacturer specification, a high mileage formulation. It was chosen for a reason. That Triton V8 is a modern design. It's made for one oil weight. It's not like the old Pontiac V8 in my Catalina that can use anything from 5W-30 if it's absolutely freezing, to 20W-50 in the summer time. Those days are long, long gone.
Heavier weight oil is just going to make it use more oil over the long term, as will 7500 mile oil changes if you're not adding as it uses it. My 1999 Ranger has almost 281,000 miles on the odometer and it loses around a quart every 4-5k (my oil change interval). I check it once a week.
Oil is cheap. Engines are expensive.
