Hi everyone. I've been on and off these boards for years. First with a 2003 350Z , and I'm just about to get a 2005 G35 MT Coupe with 88K miles, meticulously maintained. All good.

I know there's 100's, if not thousands of oil threads. But this guy's dealer, Sewell up in Dallas ( they're big and well known ) recommends and uses conventional oil on their G35 oil changes. I myself am not particularly brand loyal. I've gone back and forth, conventional, synthetic, and blended on all 3 of my cars with no worry. They all do fine.

Just interesting abiout the dealer, you'd think they would want to wring every last penny out of their customers by using synthetic.

Any ideas ? Please remember , I'm not asking you what oil you use. I'm happy for you, truly I am. But that's not my question :-)

Thank you all...

 

Some people feel "older" engines that started on traditional oil should stay on them. Everything from Synthetic oil can damage seals to it is to thin are things I have heard. I can say I have been using Synthetic oil in my car since 2012/ 2013. I only do an oil change once a year since I only put about 6k miles a year on the car. Brands.. everything from the purple stuff but more commonly Mobil extended. $25 for a five gallon jug and a good filter. I changed the valve covers two years ago since I had the traditional leak we all get but oil is great. No leaks, engine runs fine.

 

Interesting recommendation. From my experience dealers here in NC use bulk Nissan blend for standard oil change. Synthetic is extra.

 

The only noticeable difference between a conventional and synthetic is the actual physical size of the molecule. The synthetic is significantly smaller, the VQ35DE is notorious for sucking oil past the rings, a smaller molecule is easier to make past the loose ring tolerances, therefor synthetic is more likely to be consumed by the engine. However synthetic allows for higher miles on the oil so you can have fewer oil changes over the life of the vehicles. It basically ends up costing the same amount across the life of the vehicle, you just have to do fewer oil changes with synthetic but if you're consuming much oil it's much more expensive.

That's why they're not recommending synthetic for you.

I recommend using conventional for the first oil change just to see how much oil the engine is actually drinking, check your oil level on a cold engine ONCE PER WEEK until you know exactly how much oil it's using, expect to be topping off a little bit every week because it's incredibly rare to find a VQ35DE that doesn't drink oil.

If you don't have an oil consumption issue (only using 1 qt per 3k miles) then feel free to switch to synthetic but be aware the consumption will be worse on synthetic. If you're drinking a quart every 1k miles I would not recommend synthetic.

If you want to use an oil that provides superior protection to the engine then switch to something with higher ZDDP levels than modern highway use oil. Our VQ was engineered to use ILSAC 3 oil which had ZDDP content of roughly 1200ppm. All the highway use oil you will find now in 2012 is ILSAC 5-6 oil which has ZDDP levels of only 350ppm.

I recommend Valvoline VR-1 oil, it's sold as a racing-only oil since they can't legally market it for highway use due to the EPA mandating oil companies only sell ILSAC 5-6 stuff for highway use, however you can buy racing oil which is typically just the older ILSAC blends with the higher ZDDP and the VR-1 is basically just ILSAC 3 oil.

Conventional or synthetic is your choice, just depends on how much oil your engine drinks, personally I have to use conventional in my '06 rev-up.

 

this is excellent, thank you very much. I passed on a 2007 AT to get this 2005 manual, even with the oil issues. I just couldn't do an auto in this. And I'll likely stick with conventional.

Please see my new italian tune up thread. Your knowledge here is EXTREMELY helpful. Thank you again

 

My car burns a quart of oil every 1500 miles.

So I do a full oil change using Mobil1 full synthetic. Then I keep track of my mileage and every 1500 miles add another quart of the cheapest full synthetic oil I can find. Since I keep replenishing my oil with new stuff, I do my oil changes every 12,000 miles.

 

Best thing you can do with a VQ that's burning oil is add an oil pan spacer, they're like $80 and gives you another 3/4 of a quart of oil in the crankcase. Super easy to install, that way you never are running LOW on oil technically since you have extra volume.

Actually that's one of the best things you can do to a VQ regardless of oil burning status

 

The old engine creates huge friction and here zinc reduces the friction. That's the reason the old engine should use conventional oil that comes with high zinc to reduce friction.