Wheelman916

So after some time checking out various threads, on this forum and others... Seems like there is no agreement on motor oil viscosity when it comes to these motors!

Some recommend sticking to OEM 5w30. Some say stepping up to 10w30 is best. Others say a 5w40 is better for the LT1. Some say 0w40. Yet others go for 15w50...

Currently have Rotella T6 5w40 and ACDelco filter in my Z. It's what the previous owner ran. But I'm thinking of stepping back down to something slightly thinner. (T6 5w40 runs fairly high viscosity... over 14cSt @ 100°C)

Oil filters is another argument altogether. Some claim filters like Mobil 1 are no good on the LT1. Some stick with OEM ACDelco. Most advise to stay away from fram. ACDelco lists like 5 or more different filters, all supposedly being correct for the LT1. Others run the longer filter meant for trucks in place of the stubby filter.m

So what oil and filter are you guys running? Back when I had my last Camaro, in my youth many moons ago, I just ran Castrol GTX conventional and an orange Fram... But more recently, I was a huge fan of Amsoil and Pennzoil with my Mustangs. Running 0w30 or 5w30. But those modular motors seemed to like thin oils... With Ford actually recommending, and many people running, 5w20 with no ill effects.

SuperSport01

There's nothing wrong with the oil and filter what your using. I however prefer WIX filters to almost anything else due to their high quality, inexpensive cost, and they're available at many parts stores. Any name brand oil that is on sale can be found in my street cars. Now a race motor will only see either Mobil1, Amsoil, Valvoline VR1, or Brad Penn.

lt1-xjs

I run Mobil 1 5w30 and the long M1-302 filter on my LT1. I've used Fram for the last 45 years on everything else, without issue.

bufmatmuslepants

iTrader: (3)

I just use whatever name brand 10w-30 synthetic is on sale and a purolator or k&n or Mobil 1 filter, I just stay away from Fram, that's my own choice, everyone has their reasons. I also stay away from regular penzoil, in my work van that was a 4.3 astro I used to get the oil changed at a shop and didnt pay attention to what oil they used, but always noticed around 5000 miles at oil change time it felt sluggish, I asked what oil they were using and it was penzoil and that was it for me, started using a different shop that used motorcraft or something else and never had that sluggish feeling again. No explanation as to why it felt sluggish, but after all the penzoil sludge research I stay away now. Penzoil platinum I have no qualms with tho.

Shownomercy

iTrader: (1)

Rotella T3 and a Wix.

Same as the truck

draggin97s10

iTrader: (2)

I've run rotella before...I believe its high in zinc content or it used to be

216StealthSS

i roll with OEM Acdelco filter with royal purple in my SS, in my tahoe i run the mobil1 high mileage with a delco filter. i always noticed mobil1 on the filler caps of the LS series, but i was told its who made the deal with car manufactures at that time. currently im seeing "dexos" on the oil caps these days, i was told oil is oil from napa brand to the top advertised engine oil. i like sticking with one oil without switching everytime, just the way i feel.

Jr.Samples

Use Royal Purple 10W30 with an AC filter. I tried the High Mileage Valvoline 5W30 in my 5.3 Yukon and now it has a tic on start up like a lifter struggles to pump up when cold. Not too happy with that.

216StealthSS

i also use 10w30 in all my cars, winter beaters and my camaro. no issue with tick with my 5.3L in the hoe, as i have heard those engines to have a lifter tick. 185,000mi and seems to be fine.. along with over 5,000 idle hours.

Purple Poncho

iTrader: (1)

German Castrol here and a K&N filter. I won't use the k&N anymore as, IIRC, they are now made at the Fram factory or some ****. I'll use Wix frm now on.

BALLSS

OP

use 5-30 as that is the "weight" GM specs. Any quality brand be it dino or syn. WIX is what I and many others regard as the better off the shelf filter

If your motor is rebuilt and has wider bearing clearances, a thicker oil (10-40 or 20-50) is often used BUT confirm with builder.

Wheelman916

Okay. Seems like many are running 30 grade.

Car has almost 80k miles. I don't think the motor has been rebuilt or replaced.

I have half a case of Pennzoil Ultra 5w30, API SN, sitting in the garage. So I'm thinking I might put some of that in the Z.

My only concern: Ultra 5w30 has a virgin viscosity of around 10cSt@100°C... Where as the current fill of Rotella 5w40 has a visc of over 14cSt@100°C. So I'm looking at roughly a 40% drop in viscosity from one to the next. Will this impact oil pressure dramatically? I've read a lot of threads lately about monitoring oil pressure with these motors... though I'm still trying to understand why and what to look out for.

216StealthSS

i have ran into this with OEM filters and "aftermarket" filters, fram,wix,etc.
a friends 08 crown vic PI, i do his oil changes. i read in the owners manual to use OEM motorcraft filters only or you may get a knock at engine start-up. he didnt want to wait for me so he changed it and put a fram filter on it and he calls me says, my engine knocks at start-up. told him to swap the filter back to OEM and no knocks again, i have found this in heavy-duty truck apps also, used a baldwin on a cummins engine (which requires fleetguard filters) truck was throwing a low oil and check engine light, culprit was a drainback valve that lacked in the baldwin filter. i cut open multiple filters and mostly i would stick with OEM, unless specified by builder which to use...

Wheelman916

After reading about oil pressure, I decided to go for a drive and check mine. I don't know how accurate the in-dash oil pressure gauge is, but here's what it looked like it was indicating:

Cold start idle: 40-50
Warming up driving: 40-50
Warm idle: 20
Warm driving: 38-40

I haven't taken it WOT yet, but when warm, under load but not flat out, up to about 4k rpm, the needle stays right around 39-40.

This is with the current fill of oil, which I was told is Rotella T6 5w40.

What can I learn from this?

jewbacca

iTrader: (5)

IIRC the service manual states that 6 psi per 1k RPM when warm is within spec on the LT1. Don't get hung up on hot idle oil pressure.

96capricemgr

iTrader: (1)

How many of you have validated your oil opinions with Used Oil Analysis?

Far as pressure, pressure is NOT actually what keeps the bearings from hitting the crank, it is more like hydroplaning. We keep an eye on pressure because it is easy to measure and a deviation from norm can tip us off to a problem. If pressure gets too high the pump goes into bypass and all that extra oil isn't even making it to the bearings.

Far as the "use what GM recommended" argument, if one actually reads the owner's manual GM allows for 10w-30. The 5w-30 was a CAFE thing and has more to do with CAFE than it does what is best for the engine. If an OEM can spec a thinner cold viscosity oil and improve cold start mileage .01mpg and maybe shorten engine life from 250K to 200K then it is a no-brainer for them and they would do that

moehorsepower

iTrader: (3)

Exactly

Shownomercy

iTrader: (1)

Rotella T3 is a pretty common oil in the diesel land and based off of many of their UOA, I can feel very confident that it is doing just fine in my puny SBC. Is that scientific? Absolutely not, but it makes me warm and fuzzy to have an overkill oil in it.

350 groundpounder

iTrader: (5)

I'm running Valvoline 5w-30 Full Synthetic High Mileage with the long version K & N oil filter which has that lovely 1 inch nut on it to make it easy to take off and on. I have always liked Valvoline.

Opinions vary about oil and filters more than anything I have ever read about lol.

Seems like people tend to like Mobil 1, Royal Purple, and Amsoil. Wix filters seem to be really popular.

If all the oils were studied, My guess is that Amsoil would come out on top. I don't run it currently because it is slightly expensive and in the end I bet my engine will still run for years with good old Valvoline.

Wheelman916

Isn't that the truth. Lol

I like the look, and price, of the K&N PS-3002. It's the longer truck filter version of the Ps-2002. Not as good of a filter as the HP filters but for 3000k mile oil changes I'm sure it will hold up at least as well as the ACDelco filter. But WIX seems to be so highly recommended. Anyone have the part number for the longer WIX filter? The stock length one is 51069.

I'm thinking I'll either go with Pennzoil Ultra 10w30. With its solid viscosity starting at 10.5cSt@100°C, super low NOACK of 4.8, HTHS of 3.3... and most of the UOAs I've checked out online show good wear numbers and low shearing... It sounds like a really robust 30-grade.

Or, Pennzoil Ultra Euro 5w40. Virgin viscosity of 13.2cSt@100°C, while still rather thick, is a good full centistoke lower the Rotella's 14.2cSt@100°C. Also, pretty low NOACK volatility at 6.8% and HTHS of 3.88.