I don't think so, at least not in my case. I used 15w/40, 0w40, a mixture of 0w30-15w40, same results.
The anser is NO. Fuel dilution will occur regardless of oil viscosity.quote:
Will a 15W-40 oil vs a 5W-40, help reduce the amount of fuel in the oil? I assume that most of the fuel entering the oil would be during the start/warm up period. As such, it would appear that a thicker oil would help to reduce blow-by.
Does anyone know for sure?
The 6.0 definitely prefers a lighter weight oil versus a heavy one. The HEUI setup pumps the 30W easier than a 40W.quote:
Originally posted by wtd:
My girlfriend drives a 2003 Superduty with the 6.0 and when the dealer was changing the oil under the maintenance plan, they used 10W-30 Motorcraft diesel oil. Thats all they recommend for this engine. When I started changing the oil for her, I called up a few other ford dealerships and it was basically a split between them recommending the MC 10W-30 and the MC 15W-40. She decided to just keep using the 10W-30 since it seems to work well and she has not had any problems yet. Her truck has almost 55,000 miles on it and she changes oil every 5,000 miles.
Wayne
I use Amsoil 5w-30 with excellent results. I do have a 7.3 while is not a 6.0 Amsoil is a top notch oil with extendable oil change abilities 25,000 to be exact on a stock engine.quote:
Originally posted by wtd:
My girlfriend drives a 2003 Superduty with the 6.0 and when the dealer was changing the oil under the maintenance plan, they used 10W-30 Motorcraft diesel oil. Thats all they recommend for this engine. When I started changing the oil for her, I called up a few other ford dealerships and it was basically a split between them recommending the MC 10W-30 and the MC 15W-40. She decided to just keep using the 10W-30 since it seems to work well and she has not had any problems yet. Her truck has almost 55,000 miles on it and she changes oil every 5,000 miles.
Wayne