There is a very good oil analysis thread here: VQ Oil Analysis and Info - MY350Z.COM - Nissan 350Z and 370Z Forum Discussion and specific to the VQ engine. It's likely the most comprehensive and fact-based discussion of oil brands and types that has been posted. Based on the progress and data based there, I've elected to run Mobil I 0-40W FS for years. Castrol had a 0-30W synthetic that was good until it was discontinued. Castrol Edge 5W-30 will likely be fine, but I like the higher viscocity protection of the upper range of M1 0-40 a bit better. Read through at least part of the thread to gain a better understanding of the oil properties needed to keep the VQ in good shape.

 

Dump the low vis oil, Castrol is the one to use but in the 10W-30 to 10W-40 range. Low vis oil regardless of brand can't take the heat and break down. Mine has 118,000 never used a drop and been 10W40 from day one. Castrol of course.

 

With the refinements in multi-viscosity weight synthetic motor oils, this is not a concern any longer. As an example, M1 0-40W still pours like a 30 weight and can stand up to high heat. I use it in my street and race Zs during the heat of summer. UOAs on both show negligible wear on either the VQ35DE (street) or VQ35HR (race). Even after years of use, neither engine uses oil between oil changes.

BTW- Aiden350Z has never responded to this thread after posting a couple of days ago. Where are ya?

 

Natual gas pen soil 5 w 30 first I use Lucas oil stablizer both origal and new synthetic ,elimnates dry starts most important gets rid of high temp burn off good luck

 

Thanks guys appreciate the help, I’m going to go for the Castrol Edge 5w30 M, that’s what I’ve been recommended for a few places

 

Good to hear from ya- there are far too many 'one and done' posts around today. Congrats on your '05 Z33 purchase BTW- how many miles are on it? Which model?

 

Thanks man! I’ve got the manual Grand Touring Model and it’s on 80k, it took me quite a while to find one that’s still in decent condition but I’m really enjoying the car so far!

 

You're welcome and the Grand Touring models are quite rare. How many miles and what color?

 

It’s on 80,000 miles and it’s Sunset Orange (I’ll probably change the colour later down the line)

 

04 Manual Touring - Drive it in scorching US Southern temps - 5w40 full Syn Edge Euro. No blow-by issues , redline when froggy.

Good luck