the viscosity us not that much lower or doomsday pending as some would suggest. Maths say i'm running 8\25 weight.

Anyhoo I am still under a full year of owning the rig and I am ''one of those guys'' who will NEVER EVER SEAFOAM or use ENGINE RESTORE after visiting the Maxima forums. so I reduce the weight slightly and add in the higher detergent oil to accelerate the cleaning of the block..

It is simply a way to clean the engine over time and more importantly not F^&k up the top end which is what a bottle of oil conditioner might do to the tiny oil channeled OEM blocks for second gen units get a ggopy hunk of sludge or hard carbon. I play very conservative to oil cleaning a block. hearkens back to owning a rat-tat-tat-clicky izusu block.

As a previous Izuzu Rodeo owner with the 3.2 block that had serious lash issues (ever hear the loud ticking in a izusu?) without fastidious oil regiments I feel comfortable running a reduced weight. I feel further comfortable since I dont race all that much with a reduced weight.

now if I spent 50% of my time running more than 3k rpm ... i might run thicker. but I don't and spend most my time in commute.

as stated before. grain of salt and all that.

 

No contest .. it is a NICE car to pilot and it feels like they built it around you once you get it all adjusted (seats mirrors wheel).

 

What math are you using to calculate oil viscosity from blending two different types of oils?

 

just basic internet math ..

normally i like to run (1) qt 5/20 of the high mileage stuff for the better detergent to (4)qts of the manual recommend 10-30w.

after 2 weeks the oil monster rings will make me add another 1/2 qt of 5/20
then 2 weeks after that another 1/2 qt or so.

in the end I have 1.75 to 2.0 qts of 5\20 high detergent high mileage oil to 3 or 3.25 qts of 10-30

It is by no means science since my engine temp can differ from someone elses, ambient temp plays in as well as age of the oil. but at the high end ((5+5+10+10+10)/5) runs about 8w-ish in a static 'perfect world' value.. +/- human error in pouring

on the low end if could be ((5+10+10+10+10)/40) for 9w in a perfect world..

but im less worried about the bottom weight as the certified weight. i want thinner oil .. even if it is considered ''heavy oil'' .. so ((20+20+30+30+30)/5) yields a perfect static internet maths world value of 26w at the highest ratio I will tolerate.. no more than 2-Qts of 5/20 ...

mostly I end up with 1.75 Qts of 5\20 to 3.25Qts of 10\30... so roughly ((1.75*20)+(3.25*30))/5

not for performance reasons .. just for a thinner blend of high detergent stuff to very slowly over time keep cleaning away. back story is i just got the car less than a year ago.. and I am a AVID SEAFOAM hater... so this is my personal choice of how to do a little extra cleaning.

since I do not race (more than once a year and with straight 30w), and spend most my time under 3000rpm ... I feel for *me* this is a soulution I like,

again ... grain of salt, it's the interwebies and Ymmv ...


post edit .. erm edit. my VQ35 loves eating penszoil syhthetic... and I do change it every 3k regardless.

 

Whatever lubes your crank.

 

There's nothing wrong with mixing weights. I have an older friend who has been in the car game for 40+ years (owns multiple very high performance mopars), and he mixes his own blend of 15w/40 diesel oil with 0w/20 synthetic for his srt8 challenger. Not sure the ratio.

He has a small fleet of work trucks (3), a G37 sedan (his wife's), an srt-8 challenger and a sub 10 second 67 Dodge Dart Swinger and does all his own work/maintenance. Just to give you a light background on his expertise.

 

I'm not trying to say your friends are wrong.... I'm just saying there are engineers who go to school and have larger sample sizes that do stuff like this.

W/E 15w40 and 0w20 make to be, if it was good enough to be used on cars or even high end stuff, it would of been made by now. Even if the mass market guys like BP and castrol wasn't interested, amsoil, redline, royal purple would of.

But whatever... An 05 with full bolt-ons should be able to run with a 07+ stock. I might give the edge to the 07, so if you want more speed and power, get an upgrade. You want more power, upgrade to a different car. These cars aren't powerhouses, they make good power but not close to these turbo cars.

 

I don't really like seafoam either, but check out chris fix's video on YouTube about it. He takes a camera inside the cylinder for you to see cleanup on top of the cylinder. It does something to clean out varnish!