Using 5W-40 on Z's with no oil cooler

Zeto

I received advice from a tuning shop to run 5W-40 oil as opposed to the 5W-30 since I don't have an oil cooler. They said the heavier will absorb the heat better and the heat will break down the 5W-40 viscosity to a lower weight. Is there any truth in this?

gumpy

yes and no

Yes a w40 oil will be thicker at higher temperatures and protect better...

No 5w30 is fine for normal driving.

Zeto

Do you think it would be detrimental at all to run 5w-40 during the summer months?

Modshack

Could be...The VVEL system is pretty complex.....I'd stick with factory recommended viscosities.

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6spd

older cars or newer, more simple cars it won't matter what grade you run for most intents and purposes, but with such a complex motor as this one and many others these days, I'd stick to factory specs.

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Geoff-AU

Factory spec is safest. Nissan will have a bunch of lubrication engineers who have settled on the "most correct" viscosity for a wide range of reasons. But as Spooler said there are also regulatory hoops to jump through so "reasons" doesn't just mean driving conditions. If a 5W20 oil and a 5W40 oil both work fine but emissions is better with the former, then 5W20 or 5W30 will be specified and 5W40 will get dismissed.

Look at 2011Nismo's graph a couple of posts up. The VVEL system has to work with 5W30 oil that has a viscosity of 50 at 40 degrees C. At 0 degrees C the viscosity will be 100+ and the VVEL still has to function (at least under low engine stress, to idle the car and drive gently until oil temperature improves). I could fill my car with 5W30 and flog it as soon as the oil temp needle has started to come up, at 80C 5W30 oil has the same viscosity as 5W40 does at 100C.

There is some truth in "thicker oil provides more protection at high temperature" and "thinner oil flows better so it removes heat well" and so on. But unless you are building a 1000hp beast or spend most of your time above 5000RPM it matters a lot less than you think. I used to spend a good half hour staring at the oil aisle before making a decision but the fact my engine didn't blow up doesn't mean fussing over it that much was justified

Zeto

Gotcha thanks!

PapoZalsa

I'll stick with the recommended oil weight and the 3 yr Warranty can worry about the rest.

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sonic370

stick with 5w30 it should be ok. just watch the temp and check your oil every
fill up. here in texas the temp can go from 220 to 240 for no good reason.
it can be 85 or 100 outside. had my first oil change at 3000 am now at 5000
and have not used a drop of oil. i use mobil one.

brainrain

Hello,

Since 2010, does anyone use 5w40 oil ? Nissan in the south of France recommend 5w40 oil instead of 5w30 due to the heat.
What about in california, Florida or Texas ? it's very hot there

I do only 5000 km (3100 miles) per year. I only drive on weekends but I often accelerate hard.

Zyonara91

Just stick with a thicker 5w30 I would say. Motul EFE, Redline 5w30, M1 ESP 5w30 and PP Euro L 5w30 are available. They have a high HTHS rating (3.5, which is a good thing) and they run on the thicker side of a 30 grade oil.

I used Liquimoly 5w40 once, never had a issue, but I dumped out the next season without any ill effects.

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brainrain

thank you

In france, we don't have an extreme winter compared to USA or Canada. But I try 5w30 of mobil 1

Spooler

I ran 5w40 with no issues before. I now run 5w50. It will work just fine.

Rusty

Mobile 1 0w-40 Euro blend. Has everything you need.

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brainrain

I think 0w40 is for country where it's very cold, isn'it ?