I bought my G in March of 2019 with 122k; 2005 Sedan 6MT (Rev-Up). I changed the oil right after purchase with Royal Purple 5w-30, and to be perfectly honest my G has been drinking it. It's hard to say how much its been drinking, because the dipstick is so hard to get a good read; I'm sure as a result I have over-filled on occasion. I'm used to just checking oil dead-cold in the morning, but the owner's manual for the G says to wait for 10-20 after driving. If the car is going to drink oil that is close to $40 a gallon, I would like to see if there are other alternatives.

This aside, I am getting close to an oil change and I was looking for a recommendation. I've done a fair amount of reading, and the German Castrol 0w-30 was the choice of many on here, but it's not available around me. Other options I've heard of are Mobil-1 0w-40, or a variety of other brands in 5w-30, which is all contested by oil sample testing. My issue is a lot of these posts are from the 2000s/mid 2010s, and a lot has changed since that time.

For my mileage, what is the best option aside from GC? It is my daily, and sees spirited driving only when fully-warmed up. Brand and weight would be appreciated.

As a side, I also could change my trans and diff fluid at any point when I have the time. What are the recommendations for transmission and diff oil, brand and weight?

 

Ignore anything the manual says about when to check the oil level. Always do it on a cold motor that has not been driven.

You're correct about MANY things changing in the last decade, the oil on shelf they are selling today is NOT the same oil that our engine was engineered to use. I'll dig up a thread from a few days ago where we were just discussing this.

 

Ok read this thread, it covers all the important points so you can make an educated decision about HOW to select oil for an engine.

https://g35driver.com/forums/engine-...-question.html

 

As in its better.... got it. It's way better now.

 

In your situation, I saw how much oil I used in a 3000 mile interval with a given oil by doing my own oil change and measuring it with the old oil bottle. After that I just added that much in between intervals, and every once in a while I check again to make sure the rate hasn't increased. If I know I'm going to be doing a lot of aggressive driving like an autocross event or cruise sometimes I'll add another 1/2 qt right before setting out

Also, get an oil catch can, it'll help slow the death of your motor however slightly, and even with the OC still last over 200k easily... unless you have a revup, which I think only came in the coupes

 

@cswlightning in your case I STRONGLY recommend adding an oil pan spacer, you can pick up the Z1 Motorsports one for like $75 and it adds an extra 3/4 qt volume to the crankcase and is SUPER easy to install.

 

From what I gathered in the posted subtopic above, it seems like oil with higher ZDDP content in the 1000-1200ppm range is ideal, 5W-30 is the weight I'm looking for, but is there a case to switching to conventional at this point? I do not mind changing my oil every 3000 miles. I've been doing it on my Nissan truck for the last few years.

I've read some used oil analysis charts as well, and it seems like the Castrol 5w-30 is a good bet as well. Same with the Amsoil 5W-30.

If you can't tell, it seems like I'm suffering from some information overload. My G has a Rev-Up, so it drinks the Royal Purple, which I've seen a few times on 350Z forums.

 

The VQ35DE was designed to run on API SJ/SL oil which was ILSAC GF-3.

Zinc and Phosphorus for that oil varied but was generally regulated to between 1000-1400 ppm. That's why I switched over to the Valvoline VR-1 conventional oil, the ZDDP levels are exactly what the engine was designed for.

I've wondered for a VERY long time if that's why the rings on the rev-up motors burned up so quickly, because ILSAC GF-4 became mandated in 2005 but the engine was never designed to run on that 850ppm ZDDP oil.

The newest ILSAC GF-6 mandate goes into effect May of 2020 and restricts ZDDP levels even further down to 650ppm max. I forsee this will cause the RAPID destruction of all engines built pre-2010.

The conspiracy theorist in me thinks that the hive minds behind this whole API/ILSAC bullshit is the same environmentalists that were chaining themselves to redwood trees during the 90's. It's pure genius though, if you can't outlaw the vehicles then just design motor oil that causes them to prematurely fail and force exorbitant manufacturing costs on the OEM because of machine tolerances and special equipment to inflate the prices so people can't buy as many cars.

 

The Valvoline VR1 Synthetic is an 1100/1100 oil which would be a great synthetic alternative.

Generally speaking, when you use synthetic you can get away with slightly lower ZDDP levels anyways because the oil doesn't shear as badly.

You will have to base that off of your oil consumption though, synthetic is a smaller molecule and thus is more likely to be sucked past the piston rings. If you were already have consumption issues I would stick to conventional.

Oil change interval on this motor is 3750 miles, not 3000.

 

I am a sucker for a good conspiracy. Thank you for the clear-cut answer.

 

The Gear Gods™ demand I spread the gospel, happy to oblige.

 

Are you using the 10w-30 VR1? I am not seeing any 5w-30.

 

Yep, the conventional VR1 10w-30.

If you want to use 5w-30 I'd look into that Amsoil diesel 3000 one that was in the other post I linked. There's nothing special about diesel oil btw, it's just marketed specifically for a couple diesels like the baby Duramax that comes in the new Chevy Colorado.

 

Oil threads are hilarious, but this is a truth. I've been using diesel oils in the race bikes for a while now.

 

Right! Sometimes I think that oil threads need their own subforum like the Politics one.