American owners manual tend to recommend thinner oils because of stricter emissions and fuel economy standards, also while Xw20 is very common in the US & Canada I'm sure most of what you'll find in Sahara is more along the lines of 15w40, 20w50, and 25w60, so recommendations for oil are based on what's available in that region. Typically a heavier grade of oil that what the manufacturer specs is safer but not the other way around, a low HTHS 20 grade oil in a high revving high specific output super car engine like the OP is suggesting sound like a potential recipe for disaster.
How to Determine the Correct Oil Grade for your Car
- Thread starter AEHaas
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Except when it comes to computer controlled variable output oil pumps.
Correct, oil pressure really doesn't keep the moving parts separated ... viscosity along with parts motion does. Oil pressure is just the product of the PD forcing a volume of oil through a restrictive flow path. Pressure means there is some volume of oil flow through a restrictive flow path ... that's about it. The higher the flow and thicker the oil, the higher the pressure.
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It's also because the pump doesn't hit pressure relief sooner at high RPM from thick cold oil, which would cut the pump's flow output to the engine.
I would also think thats because they want all the moving parts to be thermally stabilized. There is some expansion of parts from cold to hot, hence clearances. More clearance at colder temps, dont want that at 9500 rpm lest you spin a bearing.
OVERKILL
$100 Site Donor 2021
This is also correct. On top of that, many additives in the oil are heat activated.
That said, standby diesel gensets go from off to full load and max RPM pretty much instantly and they most often have 15w-40 in them and still last a stupid amount of hours. The same goes for OPE, boats...etc.
An engine that spins to the moon may be more sensitive to clearances that will change during warm-up and the dimensions and straightness of parts. My E39 M5 (and I think this is the case with all M cars) had a variable redline that increased as the engine warmed, as BMW clearly didn't want you exploring the far side of 7K with a stone cold engine.
Is it someone who caters ham?
wemay
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4WD
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Yeah, as I pointed out before … when mine shifts axis of symmetry … the pressure jumps north of 70 psi based on “demand” (position of electronic throttle) and stays there as the RPM’s increase.Except when it comes to computer controlled variable output oil pumps.
For most folks … the oil selection these days is 0w20 or 5w30. No chance I’m going to see a difference in pressure with 5w30 - and I don’t think that engine is potent enough to need a 40.
I see. I need to check it out.
Thanks.
4WD
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Yeah aside from some sports cars - mostly trucks or truck based SUV’s …
Some of the best entertainment on Bitog ever. Running a car on the track using xw20 with oil all over the goggles from the car in front was hilarious.
"Caterham was was/is a strong proponent of thinner oils. "Thin as possible, thick as necessary""
I really like that one! I'm going to ask him if I can use that.
I really like that one! I'm going to ask him if I can use that.
OVERKILL
$100 Site Donor 2021
I don't think he was the first to use it, I believe that was @Jim Allen and CATERHAM quite liked it and used it frequently.
Not me."Thin as possible" = running on the ragged edge.
Pressure of fluid the resistance of flow. Running a hydraulic pump [the oil pump on an engine is indeed a hydraulic pump] that is in a closed circuit that shows 4,000 psi on the gauge , will show closer to zero psi if the hoses were disconnected from the resistance. It is the function of the oil pump to move the oil. Slower flow will give the fluid more time to pick up the hear if that is where we are going .
I agree. I think if my 3.6L Pentastar followed the 10 pound/1,000 rpm rule/guide I'd have problems.
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