5w-30 vs 10w-40
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Is this fluctuation observed through a stock gauge or a reliable aftermarket mechanical one?
Possibly yes.
OP does of course rise with engine rpm bur at a steady rpm it should be stable.
Under what conditions does it fluctuate?
OP does of course rise with engine rpm bur at a steady rpm it should be stable.
Under what conditions does it fluctuate?
That just normal oil pressure behaviour.
Stick with the 5w30 grade oil.
Stick with the 5w30 grade oil.
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10W40 won`t hurt a thing. Is this a VQ? I know the VQ Maxima`s FSM lists anything from 5W30-20W50.
Originally Posted By: aquariuscsm
10W40 won`t hurt a thing.
What about startup wear? That 10W-40 takes a full 5 minutes to reach all
the bearings on startup, but 5w30 only takes 2/100ths of a second.
10W40 won`t hurt a thing.
What about startup wear? That 10W-40 takes a full 5 minutes to reach all
the bearings on startup, but 5w30 only takes 2/100ths of a second.
Originally Posted By: Merkava_4
What about startup wear? That 10W-40 takes a full 5 minutes to reach all the bearings on startup, but 5w30 only takes 2/100ths of a second.
Of course, there's always that issue of immediate, catastrophic wear.
Aside from that, while CATERHAM has eloquently stated his case for 10w30 being an obsolete synthetic grade, I'd argue that 10w-40 is about as obsolete a grade as one could possibly imagine, particularly in conventional. It was terrible oil years ago, and while oil certainly has improved, specifications have changed.
Any vehicles that currently specify a 40 weight oil are either diesels which spec HDEO (10w-40s tend to meet older diesel specs, not modern ones) or European cars, which have their own specifications, which the run of the mill 10w-40 certainly cannot meet. I can't think of any mainstream vehicle currently being sold in North America that would call for 10w-40 as the preferred grade in the manual.
For something well out of warranty that is speced for a 40 weight oil, 10w-40 would be at the bottom of my list of choices, unless it was dirt cheap. Up here at least, 5w-20, 5w30, and 10w30 are the grades that go on sale. So, my old truck and the Audi got 15w40 at a much more attractive price than what 10w-40 goes for.
I know it takes 5 minutes for 10w-40 to reach all the bearings on start up, and probably double that for 15w40, and maybe triple that north of the border.
The 15w40 was cheaper though.
What about startup wear? That 10W-40 takes a full 5 minutes to reach all the bearings on startup, but 5w30 only takes 2/100ths of a second.
Of course, there's always that issue of immediate, catastrophic wear.
Aside from that, while CATERHAM has eloquently stated his case for 10w30 being an obsolete synthetic grade, I'd argue that 10w-40 is about as obsolete a grade as one could possibly imagine, particularly in conventional. It was terrible oil years ago, and while oil certainly has improved, specifications have changed.
Any vehicles that currently specify a 40 weight oil are either diesels which spec HDEO (10w-40s tend to meet older diesel specs, not modern ones) or European cars, which have their own specifications, which the run of the mill 10w-40 certainly cannot meet. I can't think of any mainstream vehicle currently being sold in North America that would call for 10w-40 as the preferred grade in the manual.
For something well out of warranty that is speced for a 40 weight oil, 10w-40 would be at the bottom of my list of choices, unless it was dirt cheap. Up here at least, 5w-20, 5w30, and 10w30 are the grades that go on sale. So, my old truck and the Audi got 15w40 at a much more attractive price than what 10w-40 goes for.
I know it takes 5 minutes for 10w-40 to reach all the bearings on start up, and probably double that for 15w40, and maybe triple that north of the border.
It will still fluctuate, but in a different range.
Oils viscosity changes when hot/cold, and different RPM affect the pressure also.
Oils viscosity changes when hot/cold, and different RPM affect the pressure also.
Originally Posted By: awoess
stock gauge... when i stop at a red light it goes just above the L and goes just above middle when driving? never reaches H level
Does your check engine light come on? If not I suspect you do not have a low oil pressure.
stock gauge... when i stop at a red light it goes just above the L and goes just above middle when driving? never reaches H level
Does your check engine light come on? If not I suspect you do not have a low oil pressure.
Originally Posted By: dave1251
Originally Posted By: awoess
stock gauge... when i stop at a red light it goes just above the L and goes just above middle when driving? never reaches H level
Does your check engine light come on? If not I suspect you do not have a low oil pressure.
I'm yet to see a "check engine light"(the amber one operated by the PCM), that was triggered by low oil pressure... A low oil pressure light will be red and operated by a sender that connects directly to the light circuit...
Originally Posted By: awoess
stock gauge... when i stop at a red light it goes just above the L and goes just above middle when driving? never reaches H level
Does your check engine light come on? If not I suspect you do not have a low oil pressure.
I'm yet to see a "check engine light"(the amber one operated by the PCM), that was triggered by low oil pressure... A low oil pressure light will be red and operated by a sender that connects directly to the light circuit...
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