Any problems using 10W-40?

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joe603
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I've been using 10W-40 royal purple in my 97 firbird LT1 without any problems. Will this weight of oil cause any problems with the higher-reving VQ? Also, what oil filters do you guys recomend? Again, been using NAPA gold in my V-8 'bird. Thanks!


Q45tech
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BMW Z8 uses 10w-60 synthetic and it redlines higher..........I always use 10w-40 in spring and fall on my higher reving Q45 [moded 7300 redline].

maxnix
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I use half M1 10W-30 and half M1 15W-50 in Texas summer.

Joe has a great deal on M1 filters, which are probably better than any of the redesigned current Nissan oil filters.

Q45tech
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Made your own 12.5 w 40........

joe603
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Well, what is better for the engine? 10W-40, 20W-50 (30 spread), 5W-30 (25 spread), or 10W-30 (20 spread). -What would you recomend?

I live in Atlanta, so the coldest is around 20* and the warmest is 100* for only 2 months in the winter/summer respectively. Is there any danger in switching weights for different times of year?

Q45tech
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Since you are supposed to change oil every 90 days you can chose 3 annual grades based on average temperature in the period.

Normally one looks at oil pressure: cold start up vs hottest in period and bearing clearances to determine viscosity. Trading off mpg vs bearing /ring wear.

Oil coolers are there to keep the oil from oxidizing and beaking down leaving varnishes...................failing inside bearings as the temperature may be 50-hundreds of F higher than that measured in the sump [pan].

What Nissan recommends is what works well for the warranty period.

Do you care about 200-300K+ engine life? Then 100% PAO or better synthetic are a must.

BlkrwdT
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[QUOTE=maxnix]I use half M1 10W-30 and half M1 15W-50 in Texas summer.

QUOTE]

Wow , your mixing the weights? Goodluck to you.

Back to topic. Like one said, use what manufactors recommend. I used to have an Acura TL-S and those are some pretty high performance engines and they recommend 5-20w. I was skepticle too but these Honda engines are made to rev for vtec engagements , but why such a low viscosity wieght? Maybe for bearing clearance factor, oil pumps, who knows but thats what they suggested to work with that particular engine.

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szh
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I use Mobil 1 0W-40 ... year round. On a M45 though.

Z

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szh
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BlkrwdT wrote:Wow , your mixing the weights? Goodluck to you.
Should not be an issue ... particularly since the oils are identical (both M1). Even if one was very different, it would not be a problem. Heck you can even mix synthetic with dino and be fine.

Z

maxnix
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Q45tech wrote:Made your own 12.5 w 40........
Yeah, hopefully I have extended the viscosity on either end a little.

There is a page somewhere on Mobil1 site that if you just go by car, year and make, it will tell you to run 5W-30 or 10W-30 for a 1995 VH45DE. But if one drills down further to another chart, it seems Mobil is recommending a heavier weight for summer temperatures.

I am not even going to go into the high mileage blends. Don't need them yet, if I ever will.

maxnix
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BlkrwdT wrote:
maxnix wrote:I use half M1 10W-30 and half M1 15W-50 in Texas summer.
Quote »1.) Wow , your mixing the weights? Goodluck to you.

2.) Back to topic. Like one said, use what manufactors recommend. I used to have an Acura TL-S and those are some pretty high performance engines and they recommend 5-20w. I was skepticle too but these Honda engines are made to rev for vtec engagements , but why such a low viscosity wieght? Maybe for bearing clearance factor, oil pumps, who knows but thats what they suggested to work with that particular engine.
1.) Mixing weights, not brands, so compatible additive packages. Not different brands! Mind boggling, ain't it?

2.) "they" would be the OEM who is only interested in getting through the warranty period and meeting their EPA projections. Hence, they specify a light weight oil. Not meant to warm your car to operating temperatures eihter, don't you know? One "wastes" gasoline by waiting for operating temperatures to be reached, but not doing wastes your engine long term. Who cares when it's out of warranty? They don't. It's your dime, not theirs when excessive wear makes its presence known by consuming more oil.

Also have a 1990 Legend fed steady diet of conventional with frequent changes. Twice to three times the miles (have 3 different Q45), but not nearly as pretty in the oil galleys as the M1 fed VH engines.

Q45tech
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Again you must know the bearing clearances by measuring [graphing the oil pressure vs coolant temperature]. Otherwise you are just guessing what the correct hot viscosity should be. Simple you want to exceed the minimum extreme hot oil pressure in drive at idle [say 15 minutes in traffic] bu some safe amount.

If the FSM says 14 psi minimum you want ~~ 17 + psi.

My 305K Q motor still meets 15 psi with Mobil 1 synthetic 10w30 in 100F ambient idling AC on after 15 minutes of idling in gear after a 2 hour expressway drive.

The advantage of synthetic is that all the base oil molecules are the same size in Daltons, thus the friction is lower. Then your graphing measurements are accurate and won't change over the 3,000 miles.

Oil viscosity is measured brand new not after 1,000 miles.All oil evaporates the ligher [smaller Dalton] fractions and thus thickens with age. Synthetics do so at ~~ half the rate of conventionals thus the viscosity is stable LONGER.

A 50-60 weight in a synthetic is safer because it never gets to 75 weight before you drain it.


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