quote:Pre-01 modular V8s use 5W-30, 01-up modular V8s use 5W-20. However, if 5W-20 was such a great oil that gives enough thermal stability and protection while giving good gas mileage, why aren't turbocharged cars using them? All I see for Euro and Japanese turbocharged 4-banger OHC engines is 5W-40, 0W-40, full synthetic, etc... not 5W-20.
Originally posted by mettech: The 4.6L Ford requires 5W-20 oil only..
quote:Dr. T, You are always bad mouthing Mobil 1 which is one of the best oils on the market. We have seen this problem in many engines using different weights and it does not fix the problem. It is NOT M1's fault it is a design problem with the engine. Oil of the proper weight does not cause knocking/ticking in an engine. In My LS1 which was rebuilt because of knocking problems made noise using every type of oil and nothing made a difference! It is a design problem and not an oil problem! Mobil 1 5w30 will protect this 4.6 just fine!
Originally posted by Dr. T: Can you explain...for a 4.6? Is this engine too large? Too small? OHC? I've used 50 weights in a 1.6 Suzuki engine and my 5.6 V-12...the engine size doesn't matter what oil you use. It's exclusively the ambient temperature. And yes, your comments re: a 5-30 being too thin for towing is probably correct...but the same holds true for the 4.6...especially if it's in a Mustang. However, I've found the same thing with Mobil 1. So yes, it is the oil (with the disclaimer that I've never tried the 0-20). My suggestion...try a different brand or synthetic and report back...