Synthetic doesn't affect the seals but the molecules are smaller and it can potentially leak through old seals.

 

Wait...you guys use oil in your Z?

 

I use this in my Alfa's, but haven't tried it in the Z, yet:

 

I've always heard about the benefits of using olive oil in lieu of regular oil but haven't had the guts to try it.

 

Why don't you do a little research. We have an engine that beats up 30 weight oils. Add fuel dilution to the mix and you're below the buffer.

Do you stay at exactly 212*f/100c at the track? That is the viscosity the VQ was spec'd. I've seen temps around 260*f at the track. You would be way below the proper viscosity at that temp.

People can run anything they want, but I hear of more high performance engines running 20w50 or 10w60 than 5w30. Why would you run an oil with a lower HTHS, worse cold starting properties, and less robust overall? I'd like to see you run M1 5w30 on a FI engine. I've done it, and I will never do it again. M1 0W40 is also a Group IV PAO oil. It is also less than $25 for 5qts at walmart.

I've had my current 350z for two years, and my Z32TT for 5 years. My 300zxtt has 200k on it, and has only seen 5w30 once. Otherwise it runs T6 or M1 0W40. Its my DD which sticks with 0w40 through MN winters. Oil pressure is still 65psi @ 3000rpms, and 20psi at 700rpms. I have also ran it dry for a whole lap on the track.

We have an engine with a timing chain. Have you felt the resonance at 2300-3000rpms? You need an oil with the highest HTHS, yet stays with-in the OE oil PSI specifications. 0w40 provides that.

 

 

Sure. If you're in Watsonville, CA, there's no chance your oil will ever thin to 0w (even in Tahoe or anywhere up in the Sierra winters) nor get hot enough to raise visc to 40. Perfectly fine.

 

 

No- but depending on what brand and grade of oil you've been using, your VQ may thank you (by lasting a little longer).

 

 

We're fortunate to have an excellent thread with plenty of factual data on what works well in the VQ35HR:
https://my350z.com/forum/vq35hr/3003...-analysis.html

For my money, I use Mobil 1 0-40W FS in both my race (HR) and street (DE) Zs. It's available at WalMart for about $26 (in 2018) for a five quart jug, and is also on sale at most car parts chains if you'd prefer.

 

 

Highly oversimplified....

The numbers represent the relative viscosity (thickness, so to speak) of your oil, based on both ambient and engine internal operating temperatures. A multi-vis (multi-viscosity) oil "thins" to a lower rate for best flow when cold and "thickens" to the higher rate when hot - extremes in both ambient and op temp, say, a racing application).

First # is the thin weight (also called cold start weight) expressed as Xw (e.g. 5w or 5 Winter - the "w" does not stand for "weight" as is often confused). If it's cold out, oil will thin down to this minimum weight for cold start protection then...

Thicken up to as much as the second #, e.g. "40" for maximum protection at high running temperatures (obviously influenced by ambient temperature).

Nissan (and most mfgrs) recommend 5w-30 for most areas in North America (other areas, check your owner's manuals). Not much more protection is needed as even as there are extremes ranges of temps based on environmental factors (say negative degrees in Minnesota or Canada OR up to 110*F in Scottsdale, AZ as examples) do not require much more than this.

0w-40 then, by this logic, will thin down to 0 weight and thicken to 40 weight. But like I said, in most areas of the country, the additional swing range isn't necessary BUT it's not going to hurt.