codek

Will going from 5W-30 to 5W-40 will cause higher oil pressure?

I have a stock 2007 350z about 50k miles. The car is stock.

I'm looking at the Eneos 5w-40 but was wondering if it would be a good choice considering my car is stock

davidv

iTrader: (2)

Why would motor oil alter oil pressure? You could fill the motor with olive oil and pressure would remain the same.

Blu_Blur

iTrader: (1)

I notice difference in oil pressure between my old 5w-30 and my current 0w-40 when the oil is around 3k miles, at operating temperature and under load.

plumpzz

iTrader: (10)

hydraulic pressure depends on pipe geometry and fluid parameters. ofcourse viscocity will affect pressure.

Nexx

iTrader: (41)

+1, along with the lubablity, and proscrastinistic variables of the flux capacitors.

midz350

iTrader: (4)

nathanwl2004

iTrader: (2)

I believe there is a word for just this sort of ocassion.... oh yes..............OWNED..

NismoZ_840

iTrader: (3)

Yes, but only at higher temperatures. Both act the same (5w) when at ambient temperatures and as they heat up the oil starts to thin. The 40W thins slower than the 30w. Since the oil system volume is fixed, it takes more pressure to pump a more viscous (thicker) fluid thus your oil pressure should be a little higher for the 40w.

Here's a diagram that may help...


This is from the best post ever on oil and well worth a read by any car owner...
https://my350z.com/forum/engine-and-...-and-info.html

If that still doesn't answer your oil question, try here:
http://www.bobistheoilguy.com/

A good general rule about oil pressure is NO or very low pressure is VERY bad and of most concern. You have either a leak or the oil is so thin it's losing effectiveness. This will kill the motor. Too high a pressure is a concern too because your stressing the oil system and seals, thus the reason you don't go redlining the car right after startup, you need to let the oil and engine warm up to keep the pressure at a reasonable level and things to expand/contract as the Nissan engineers intended. You're not likely to kill the motor right away with too high pressure (except if you had a massive system/seal blow out right away), but you increase the risk of leaks and failures leading to no oil pressure and killing the engine down the road.

LMAO on the Lube poster

winchman

It depends on the temperature you're talking about. For a cold start at 0 degrees F, both would yield about the same pressure. For a cold start at moderate temperatures and at normal operating temperature, the 5W40 would be higher.

For a cold start using 5W30, I see 120 psi on the coldest days, and over 100psi on the hottest (100 degrees F)days. I doubt that cold start pressure with 5W40 on a hot day would be higher than with 5W30 on a cold day.