Camaropar

iTrader: (1)

What 10w-40 synthetic is everyone using? I'm an avid mobil 1 user but they don't make any regular 10w-40, only that high mileage crap with their 'seal' conditioners.

Reason for 10-40 is I'm using 10-30 currently and have alot of piston slap, hoping to quiet it down a little with the 10-40.

CoastieWS6

iTrader: (1)

Go with Pennzoil Platinum 10w-30.


BTW piston sap only happens when the LS1 is cold.

RPM WS6

iTrader: (3)

I use Mobil 1 0W40. Been using it for many years in all my LS1s.

NoTractionLS1

Get Valvoline VR1 10w30. Best stuff around!

NoTractionLS1

And the best place to get it is at NAPA.

RPM WS6

iTrader: (3)

Valvoline VR-1 10w30 (part #VV205) is what I use in my old Gen 1 SBC engine. It's got high zinc and phosphorus content, for flat tappet cams. You don't need this stuff in a roller cammed engine, though it wouldn't hurt either. I still prefer M1 0W40 for my modern LS1s though.

O2Form

Heavier oil is not going to help piston slap, It will help lifter noise. I went to hevier oil because of lifter noise and the piston slap noise at start up is much louder now.

mikedamageinc

iTrader: (49)

Mobil 1 makes a 0w-40 Euro formula that I just ran 5K and used oil analysis showed excellent wear characteristics in my 220K+ LS1 and supposedly had at least another 2K life. From what I've been reading tho, 40 is higher than necessary and 0w- is the best for start up and no more than 5w- should be used in most cases. I have noticed less knock on start up using the 0w-, right now I have the 0w-30 M1 and its running fine with good pressure, looking forward to comparing results with this one...

Nemesis350

iTrader: (11)

LOL well please don't put me on blast, but i'm still running royal purple... i went from 10-30 to 10-40, and lifter chatter so far seems a bit better. Piston slap? well i can't comment on that.

Not necessarily recommending RP; i'm sure several would recommend pretty much anything else. But i like it, just fwiw

RPM WS6

iTrader: (3)

In most cases, I would agree that w40 is higher than necessary, but when it comes to Mobil 1, I would stick with the 40. Mobil 1 tends to run on the thin side of their rated viscosity, and LS1s tend to show best wear with a thick w30 or a thin w40, which is why "thick" w30s like GC work well, and "thin" w40s like M1 also work well.

It will be interesting to see how the wear results compare between the M1 0w30 and M1 0w40 in your case. Please post back about that, if you remember.

Fbodyjunkie06

iTrader: (10)

Remember the first number with the W next to it is the viscosity when cold, the number after the - is the viscosity when hot. If your having piston slap when it's cold you'll want something lighter that will coat the ring lands sooner than later. You'll accomplish this with a lighter W weight not the hot viscosity weight. FWIW.

1998flamedCamaro

iTrader: (4)

I run 5w-40 castrol syntec. Couldn't be happier.

9WhiteCamaro9

I run Valvoline Full Synthetic mated to a K&N oil filter in mine and have never had a problem with it and has good oil pressure.

CamaroZ28_LS1

iTrader: (5)

Piston Slap is a normal operating condition on these engines after 98. Some have it and some don't. I have it pretty good on my SS as where my friends 02 Trans Am doesn't have piston slap. It goes away when the engine is warm. No big deal. I stick with 5w30 oil anyways.

Camaropar

iTrader: (1)

Well FYI my car has bad piston slap cold (sounds like a rod knock) which changes to minor slap when hot. I went with casterol syntec 10w-40 (one of the only full synthetics on the market with that viscosity). So far it seems about the same, maybe a tiny bit better when hot. But it also dropped a good 20 degrees outside lately too... so time will tell.