which oil weight do you use

[Sarge]

pennsoil sucks... gunks ur engine up. go valvoline

No brand of oil causes sludge/gunk. That is a myth. Improper OCI's/non functional PCV/Lack of proper op temps to burn off acids,condensation cause sludge/gunk. Pennzoil is the finest OTC oil on the market.

[ricefordiner]

Sargento theirs these doochdumpsters that keep telling me that if the switch from conventional oil to synthetic is made there is no going back. So by just flushing the motor between changes might make it possible to go back or am i wrong. By the way you fucking blow eveyone out of the water and into outer space when it comes to the oil shit! lol o nad when does the switch from 10-30 to 10-40 happen, or do you ever make the change and just stay at 10-30! thanks for all the info and evidence dude i knew old people were wise lol jk

[Sarge]

You can swap from conventionals to synthetics and back anytime you wish and as often as you like. This "myth" will not die and is a leftover from the API SH, SG, SF days. The SM rated conventionals are closer to synthetics than synthetics were 20 years ago In a fairly stock LSX motor 10-30 is what you want year round unless you live on the North Pole then go 0-30.

[Fast_Z28]

What motor oil should I use for a 1994 z28? The car did not come with a manual.

[Sarge]

What? Use what? Engine oil? 10-30 api SM rated oil. Get UOA's to determine proper OCI's.

[ScottH]

Sarge,

I see lots of discussion for 'normal' range LSx cars. What would you run in a forged 360" twin turbo putting down 625 at the rear tires?

Summer only car, spirited street driving, not worried about cost of oil/filter, less than 3000 miles per year driving.

[INMY01TA]

Sarge,

I see lots of discussion for 'normal' range LSx cars. What would you run in a forged 360" twin turbo putting down 625 at the rear tires?

Summer only car, spirited street driving, not worried about cost of oil/filter, less than 3000 miles per year driving.

Try some Mobil 1 TDT 5w40

[Sarge]

Sarge,

I see lots of discussion for 'normal' range LSx cars. What would you run in a forged 360" twin turbo putting down 625 at the rear tires?

Summer only car, spirited street driving, not worried about cost of oil/filter, less than 3000 miles per year driving.

Gotta love it
I would run Redline 10-30 in that car. Has the HTHS of a 40 weight in a 30 viscosity. My 2nd choice would be Amsoil 0-30.

[CompSyn]

Sarge,

I see lots of discussion for 'normal' range LSx cars. What would you run in a forged 360" twin turbo putting down 625 at the rear tires?

Summer only car, spirited street driving, not worried about cost of oil/filter, less than 3000 miles per year driving.

In contrast, the Supercharged 638 horsepower 2009 Corvette ZR-1 comes with Mobil-1 5W-30 as factory fill. The HT/HS of that lubricant, 3.09.

Of course one wonders if GM didn’t have their buddy-buddy relationship with Exxon/Mobil, maybe they would have utilized a more stout lubricant as Sarge listed with higher HT/HS numbers. Then again, the claim has been made that the GM engineers tested and track proved this car logging over 100,000-miles on this engine. I would hope if there was an issue with the lubricant used they would have yanked it.

Check out this GM testing session and be the judge:





Don’t get me wrong, I’m not exactly advocating Exxon/Mobil products. That would obviously be a conflict of interest for me. I am however rising the question of is a few tenths of a HT/HS point detrimental after a certain number? It of course probably varies from engine to engine and can only be proven through the wear numbers taken from Used Oil Analysis results.

One other option you may consider for your application, as though you didn’t already have enough good options, is Amsoil’s new 10W-30 Dominator Racing Oil.




Amsoil 10W-30 Dominator Racing Oil link

CompSyn

[Z28_06374]

I run Castrol Syntec 5W 50, you get the best of both worlds.

[Sarge]

50 weight? Why?

[Z28_06374]

50 weight? Why?

Motor has 110k on it, anything less and the oil pressure drops below 30 hot at idle which makes me nervous.

[Mr. Luos]

My favorite oil has been discountinued.

VP 5w-30 worked GREAT for me.
They told me to run Mobil 1. I refuse.
My car currently runs Pennzoil Platinum 10w-30. Planning on running Amsoil 0w-30 in it soon.

[kensz28]

My car shows 130k on it. Not sure if that is correct since it has 01-02 heads on it. I run (accidentally) rotella (yes it's for diesels) it has all the service requirements and then some on the bottle. It is 15w-40 and I have a qt of lucas in it. Oil psi is 70 at full throttle and 50 warm and idling. Hope the slight lifter tick stays away.

[wickedbeast]

everyone just stay with a full synthetic

[Z28_06374]

I was running mobil 1, but my car eats it up for some reason?

[4.8t]

i've read most of this thread and i got to say its pretty informative. i'm in the middle of trying to figure out which oil to run myself. my tahoe has ran 5w30 RP since i owned it. but it seems like everytime i drain the oil it looks like water and smells like crap. i'm not sure if i'm just beating the snot out of the oil or what.

my tahoe is turbo charged and i wonder if the heat from the turbo is hurting the oil even more. i run 10-13psi on the streets with my tc78 on the 5.3l and i run water/meth. i drive the shit out of it. i didn't build it to baby it if i wanted that i would left it stock. i also tow with it. i've been looking into amsoil cause my buddy gets the dealer price. is there a certain one i should run that won't break down so fast? i tried castrol syntec for shit and giggles and it didn't look any better. i read alot of turbo guys running rotella T also.

can you help me sarge

[DIRTY JERZY]

Stay away from RP sarge will tell you the same

[4.8t]

i understand that but where do i go from here? what oil do i go to. i don't always have the money to go amsoil (broke navy guy here) it seems rotella t 5w40 is good but where can i get it?