5w-30 vs 10w-40

[awoess]

with my oil pressure fluctuating someone suggested using 10w-40 instaed of 5w-30? is this bad advice? 2005 nissan frontier nismo 6 cylinder

 

[OVERKILL]

Is this fluctuation observed through a stock gauge or a reliable aftermarket mechanical one?

 

[oggb]

Considering that you live in Louisiana it won't make much of a difference. Go for it, I guess.

 

[CATERHAM]

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?

 

[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

 

[CATERHAM]

That just normal oil pressure behaviour. Stick with the 5W-30 grade oil.

 

[aquariuscsm]

10W40 won`t hurt a thing. Is this a VQ? I know the VQ Maxima`s FSM lists anything from 5W30-20W50.

 

[Merkava_4]

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 5W-30 only takes 2/100ths of a second.

 

[Garak]

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 5W-30 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 10w-30 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, 5w-30, and 10w-30 are the grades that go on sale. So, my old truck and the Audi got 15w-40 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 15w-40, and maybe triple that north of the border. The 15w-40 was cheaper though.

 

[mechtech2]

It will still fluctuate, but in a different range. Oils viscosity changes when hot/cold, and different RPM affect the pressure also.

 

[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.

 

[TFB1]

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...

 

[awoess]

my check engine light does NOT come on.... i think i'm over reacting a little bit? thanks for the advice.. i'll stick with 5w-30 Royal Purple