Nissan's and Heavier Weight Oil !

[CharBaby]

What do Nissan owners and others mean when they say that Nissan/Infinity engines like heavier weight oil? Do heavier oils like X-W-40,(compared to X-W-30) help to quiet the engines or make them seem more smooth, or is it that the UOA's show less ware? I've done a search and can't seem to come up with and answer, only the coments. Just what is the real deal here?

 

[mikemc]

Have you checked the used oil engine analysis forum? I'm not sure that comparing different oils in different engines will provide a definite answer, but it should be interesting reading.

 

[speedtc]

I have learned here that worrying about noise is a useless worry. Use what's recommended for your climate. I have tried GC and it hurt my MPG. I went to 5w30 and MPG issue seems to have gone bye bye. Noise is not a big deal.

 

[Al]

I think the VQ 3.5 likes a heavier oil. But other Nissans are fine on a 30 wt. The Sr20DE is fine with 30 wt. And really the VQ 3.5 doesn't really "need" it. It just seems to lower the lead numbers a bit.

 

[Cyprs]

Nissans have the steel time chain good for 200K miles, I will not use a 40 weight on a newer Nissan but I use a HDEO 0-30 CI-4/SL syn, it is a very heavy 30. There are many concerned on timing chain lubrication, the Japanese have been concerned with the thinner new oils now and chain lube. Also, a Nissan does not make as tight clearances as say a Honda requiring 20 weight oils. I have driven Nissan/Datsun for 28 years now, they do great on heavier oil, as they age to 300K I use 40 weight in them. For example, in my manual for my 05 QR25DE 4 cylinder, Nissan will allow me to use a 10-40 oil in temp range from 0F and up, that is a thick oil for winter in a four banger, and Nissan usually shows preference to dino oils too, I always use syn oil in them, no problem. 5-30 is generally the perfered all temp oil for Nissan. Cyprs

 

[CharBaby]

Thanks for the replies!

 

[nj300se]

I have a '92 Nissan with the Sr20DE motor, and as you might have guessed, I'm in NJ where the temps can go down to 0, and like last summer be 90+ many days. Well, not knowing anything about oil when I got the car, someone suggested "a good thick synthetic" for it when it was new. OK...so I pick the Syntec 5W-50 which has been used in this 4 banger since the factory fill was drained! It now has about 185,000 on it and has only been off of the 5-50 for about a year now. (I know slightly more) Never did a UOA on this motor, but it still hauls *** and does not burn any oil.