I run Penzoil 5w30 in all of my cars year round, with purolator filters. Never had any type of oil related problems, switching to synthetic on my old neon after I bought it stopped the valvetrain tick upon start up as well. It is a little more expensive, but it lasts longer.
I know I've said my montra about using 50\50 regular and synth oil and a half quart of 30 to protect the bearings. This came from the 98 FAA report on oil performance.
When I got my snow blower, it was a 2 stroke that was listed to run at 50 to 1. My local small engine shop told me, the engines are the same, but for emissions, they tell you to run less oil. If you buy a 1 gallon gas can, it has space for four extra ounces of oil, which is 37 to 1. For emissions, engine longevity is sacrificed.
I worry about Zero oils and longevity. All of my cars call for 5/30, but I run 10/40 and my own synthetic blend. I will trade off a few MPG's for a little more longevity. Years before the FAA report, Hot Rod magazine listed 20/50 as the best all around oil for efficiency and lubrication.
The viscosity of zero oils aren't much lower than a 5 under the cold temperature test protocol. It's known as the cold test because it's at a lower temperature than the engine operating temperature test, but that cold is at 40C, or 104F. The gap in viscosities grows as you get down to temperatures that the engine starts up in the real world. In winter, that difference can save you some gas until the oil and engine warm up, then there is no measurable difference between it and an equivalent 5w-x.
Even in mild temperatures, the zero oil will still be at least twice as thick as at operating temperature. Anyone referring to a zero weight oil as water is clueless.
a 0w30 and a 5w30 are exactly the same viscosity at operating temperature. The W in the weight literally stands for winter, because that is the viscosity the oil performs at when it is cold.
a 0w30 weight oil has a kinematic viscosity of roughly 57 cST, a 5w30 weight 59.5 cST and a 10w30 weight 66 cST at 40C. A cST is a centistroke, which is 0.000001 square meter per second. Water at that same temperature has a kinematic viscosity of 1 cST. In cold weather, you can't really go too low for the viscosity of your oil in the first number, since an engine made to run 5w30 is designed to operate most efficiently with the best lubrication while pumping an oil that is around 12.5 cST at operating temperature. That is why oil pressure climbs so high at start up. Don't get me wrong, you need oil pressure, but too much oil pressure means you have a blockage and you aren't circulating the volume of oil your engine needs. Either way, those numbers aren't really that far apart at what is just over 100 degrees Fahrenheit.
Even when cold, a 5 weight oil is not THAT much thinner than a 10 weight, and a 0 weight is not THAT much thinner than a 5 weight.
You should run the oil your manufacturer specs for your engine. To high a viscosity will not be able to flow properly between some parts, too low a viscosity will not build the pressure required to force it all the way to certain parts. Blending synthetic in your oil will not change anything about your oil, since it is just like mixing any other two oils, and adding 30 weight oil just raises the viscosity at cold temperatures, and will cause separation of the bonds of the additives.
The guys formulating the oil are a lot smarter than you or I (probably), or they at least have the benefit of TONS of research and computer simulations. You are not going to make better formulations just randomly mixing stuff up.
I do not believe there was EVER an FAA report to the effect of what you are saying. I know for certain Hot Rod magazine would not have listed 20w50 as the best all around oil for efficiency and lubrication, as clearances between parts on different engines vary, therefore they need a different viscosity of oil to provide proper lubrication.
A 20w50 oil has a kinematic viscosity of 22 cST at the boiling temperature of water, roughly operating temperatures. A 0w30, 5w30, 10w30 or a straight 30 weight on the other hand, 12.5 cST. The reason we don't use single viscosity oils is because that same 5 weight from before would have a viscosity of 3.8 cST at operating temps, whereas a straight 30 weight has a viscosity of something in the neighborhood of 80 or 90 cST at 40c. In cold temperatures, say 0c, that 5 weight has a viscosity of something around 500 cST (this might be inaccurate, I am trying to give this figure from memory since I can't find it at the moment, but it should be close), but it does warm up quickly due to friction.
I did have to look up these numbers, so I am certain they are very close to accurate by the way.
Also, Quaker State is just off-brand penzoil since the 90s.
Either way, multigrade oils are formulated to work very close to the same at a wide range of operating temperatures, and only change in viscosity slightly as parts expand and clearances become marginally tighter. There is a reason companies like ferrari use things like 5w40 or 10w60 (they can use such a wide range because that kind of oil is expensive, whereas honda for instance sells cars that they want to find an economical oil for to give the best available protection without costing an outrageous amount).
good post except for manufacturers recommendations. as previously noted, those recommendations are in fact influence by emissions. example: ford used to recommend(still does?) 5w20 in many of their vehicles. well, you won't catch me using that stuff in any base or brand(not even synthetic) in the heat and humidity of florida especially during summer.
i'll often go to a 0w40 during summer...usually as a top off or when replacing the oil filter only.
They have a million other ways to improve emissions, but they have only one way to protect the engine for the ever-increasing length of the factory warranty...and for the reputation of long-lasting engines that they need. Japanese brands could get away with compromising on that issue a little, they have reputation to spare, but brands of other origins do not and can not. I'm inclined to trust the engineers whose job depends on engines lasting a long time.
I'd be interested to hear what grade Ford Man uses with his 500,000 mile Ford (and other high-mileage Fords).
I'm inclined to trust the engineers whose job depends on engines lasting a long time.
even engineers make mistakes...GMs perennial intake manifold gasket, Ford's cruise control fires, Toyota's "stuck" throttle, etc.
in GM's case...http://www.dslreports.com/forum/r202...lawsuit-update...there were 2 mistakes made...recommending the patheticly poor dexcool for 100k miles and expecting plastic gaskets to withstand heat and pressures of an engine. nice engineering there!