Extra oil does nothing to increase your oil pressure. Having too little oil is about the only way oil level can affect oil pressure. But if you sleep better at night then go for it!Also have always run 11qts to increase oil psi 1-2 to help prevent the delicate bearings from deciding they are tired of functioning...
..that was tongue-n-cheek....sorry for the confusion...truthfully.... Mobil-1 has demonstrated studies that 0w30 is more fuel efficient over the life of an oil change versus 5w30...0w was once more expensive but that is no longer the case either...Extra oil does nothing to increase your oil pressure. Having too little oil is about the only way oil level can affect oil pressure. But if you sleep better at night then go for it!
I think there are no negatives if the engine is designed for it. Improved manufacturing standards and improved lubricating oil additives and additive blending have made these lower viscosity oils perform well when both are designed properly. My Pacifica minivan with the PEntastar V6 uses 0w20 oil. I the same oil is specified when the engine is installed in a 1500 also.That article from Amsoil talks of the benefits of going "thin".
What about the negatives?
Actually, Mobil 1 0W-40 does meet diesel specs for many european manufacturers. It is an excellent product for VW TDI engines and can also handle extended drain intervals due to a TBN of around 11.Mobil 1 has a 0w40 I use in my daughter's Audi, spec'd more for European cars. Not a diesel spec oil.
I think ustuplay is volunteering to do a long-term test using 0w16 in his Eco and reporting back.
Brian,I agree, there is nothing wrong about "thin" oils, as long as the engine is designed for it. We see huge shifts over the last 10 -15 years with 20 weight oils. Ford, Toyota for example, they back specced engines for the lighter oil. And even that is a bit of a sham. Viscosity is bracketed. Fort instance SAE shows a 30 weight as approx. 9 to 12 cSt at 100 C. You could have a thick 20 weight and a thin 30 weight with essentially the same viscosity. I run 30 weight in my CTD. Not because Ram says I can but Cummins says I can. I researched it a lot and found that my 10w30 semi synthetic has very similar cold flow properties as a thicker 5w40 group 3 synthetic. This at a substantial cost savings of around 2-3 $ a liter. Yes it is still a 10w but the real world potential for additional cold start up wear is negligible. My truck will long rot away before I run into oil related wear problems.
As for the 0, 5 and 10w. They are set out by tests done at varying temperatures. 0w is tested at -35 C for CCV (ASTM D5293) and Borderline pumping viscosity at-40 C (ASTM D4684). It has to fit into a bracket they have.
Can running a thinner oil give you fuel economy savings? It can but you have to do the math to see if that savings is worth the added oil cost.
shawclan5, You are correct, I shouldn't used the word lie. I should have just stated that the USA oil companies poured millions of dollars into a campaign to legally allow themselves to misrepresent a product and to deceive the American public. Before the ink got dry on the 2007 Supreme Court decision, Mobil reformulated their Base IV synthetics to Base III, it's all about the money...that was tongue-n-cheek....sorry for the confusion...truthfully.... Mobil-1 has demonstrated studies that 0w30 is more fuel efficient over the life of an oil change versus 5w30...0w was once more expensive but that is no longer the case either...
What RansomT is trying to articulating is the Castrol VS Mobil-1 Lawsuit Settled in 2007 being.... a manufacturer can label dino oils as "fully synthetic". It is NOT a lie...it was a legal decision in Ths US Supreme Court setting Federal president/law define as newly engineered oil using modern technology could be labeled synthetic here in the USA.
I don't have any material arguments with your statements. Additive technology has changed significantly since the days of the first multi viscosity engine oils.Howie, that is the idea, full group 3, 4 and 5 oils usually require less additives or viscosity improvers/modifiers to bridge the gap between having a lower "w" value and a higher operating viscosity (ex 0w40). If I could put it so bluntly. The oil should theoretically be more resistant to break down or shear as compared to a conventional/group 2 based oil. For example, Amsoil has a straight 30 weight group 4 oil that without any improvers/modifiers can meet SAE 10w30. That's just how good that base stock is.
But here is my observation splashed with some opinion: Oils have come such a long way that base stock group is really a non issue if you are using a properly specced and quality oil. Some engines shear oil, regardless of quality. 6.0 Powerstrokes are notorious for shearing 40 weights down to a 30 weight in short order. Does not matter if it is conventional 15w40 or synthetic 5w40. Wear is usually not affected but to sidestep this, people run 30 weights, with hold up better in those applications.
The oil change indexes we use for these trucks (mine included) are far short of what the oil can usually handle, unless there is something not operating as designed in the engine. Used oil analysis can show wear data, TBN/TAN, additive levels, etc.
For example, I started using UOA on my 3500. While the engine is still breaking in, the wear metals are still high but the viscosity, fuel, soot and additives should remain consistent for my index (my use is very consistent). The 11 liters of 10w30 oil were changed at 24,000km, the starting viscosity was 12cSt at 100 C. With some heavy use, lots of cold starts, I was at 2.87% fuel (less than Cummins 5% condemnation limit), my end viscosity was 11.47cSt at 100 C and my additives were barely used. Cummins gives the usual bracket for viscosity condemnation, a 30 weight must remain within the 9-13 cSt range (give or take). Other than high wear metals from a still fresh engine, the oil was completely serviceable. Heck, my soot was less than 1%. This is with an inexpensive semi synthetic, PetroCanada Duron SHP. This is a CES 20086 approved oil.
Can we get VM or FCA to give us the condemnation limits for the 3 liter? This will help you compare the numbers on a UOA to that of when VM/FCA thinks your oil is done. Sorry, this post is poorly written at this time of day...