Looking for viscosity recommendations

[virus]

1. 2009 Pontiac G8 - Heavily modified engine to include aftermarket cam, lifters, etc.
2. 5-30 is what GM recommends
3. Mid Atlantic Region
4. Normal rush hour traffic, spirited runs and occassional track use.
5. 27 miles each way in Washington DC rush hour traffic.

I've been using Amsoil since 1994 in all of my vehicles. I'm not opposed to trying another brand, but I am currently using the Amsoil HDD 5w30 and wondering if the Amsoil or another brand of 10w-40 might provide better protection and perhaps quiet the valvetrain some?

 

[Bandito440]

Which motor do you have in that?

 

[virus]

From my first post the Amsoil HDD 5w30 Diesel Oil.

 

[SLCraig]

Originally Posted By: virus
As stated in my first post the Amsoil HDD 5w30 Diesel Oil.


Motor, not motor oil.
V8, V6, etc.

 

[Bandito440]

Originally Posted By: Bandito440
Which motor do you have in that?

There were three options that year.

 

[dparm]

What makes you think the existing Amsoil you have is insufficient?

Does the car have an oil pressure gauge?

 

[donnyj08]

Originally Posted By: virus
1. 2009 Pontiac G8 - Heavily modified engine to include aftermarket cam, lifters, etc.
2. 5-30 is what GM recommends
3. Mid Atlantic Region
4. Normal rush hour traffic, spirited runs and occassional track use.
5. 27 miles each way in Washington DC rush hour traffic.

I've been using Amsoil since 1994 in all of my vehicles. I'm not opposed to trying another brand, but I am currently using the Amsoil HDD 5w30 and wondering if the Amsoil or another brand of 10w-40 might provide better protection and perhaps quiet the valvetrain some?


id stick with the 5w30. if its good enough for the factory high power vettes its probably pretty good!

 

[dave1251]

Unless there is a drop in oil pressure I would not change anything. With a HTHS of 3.5 it should be sufficient.

 

[ARCOgraphite]

PAO base = racket but if its got a good package (as amsoil does)it'll work well. You could step up to a real race oil. Zddp is king; it quiets engines surprisingly at the piston turnaround where hydrodynamic lubrication suspends and boundary takes over. POE and Di-ester base may well be quieter, as they have good lubricity, and some traction - if you want to stick with a low ash oil.

 

[dparm]

Adding to what I said above: the 5w30 is probably sufficient but you may need to run a shorter OCI if the motor is really beating up on the oil or contaminating it with fuel.

 

[CATERHAM]

HDD is not a bad choice but I'd prefer M1 0W-40.
It's both heavier at hot operating temp's and lighter on start-up due to it's high VI.

 

[virus]

Thanks for the info and keep it coming. Sorry I forgot to mention the engine info. I have the L76 which is a LS2 variant with a 6.0 liter V8. I also have high flow cats.

 

[Nickdfresh]

I'd use Mobil 1 0W-40 or Castrol Edge w/ SYNTEC 0W-30...

 

[mechtech2]

Is the engine modified yet?
Your post says "to" include - as in the future.

 

[virus]

Originally Posted By: mechtech2
Is the engine modified yet?
Your post says "to" include - as in the future.


Mods I currently have are as follows:
Cam 226/230 .598/.608 113+1 LSA
Lunati High RPM Roller Lifters
Lunati dual valve springs
Ported/Milled heads with valve job
Ported throttle body and intake manifold
CAI
Kooks 1 7/8" Long Tube Headers w/high flow cats and 2.5" exhaust

That covers the engine specs. It's a high 11 second car on 20" all season street tires.

I do get quite a bit of blow by with the catch can. I usually empty it every 3-4 weeks.

 

[Highline9]

Do you have cast or forged pistons? Thats a healthy cam bet it sound good.

 

[virus]

Originally Posted By: Highline9
Do you have cast or forged pistons? Thats a healthy cam bet it sound good.


They are the stock cast pistons. I had a slightly higher lift cam in there before at 223/231 .610/.617 116+4 LSA. Unfortunately the shop that did my original install with the DoD delete didn't torque the heads or rockers to spec and caused damage to the lifters and the cam. I was weeks away from catastrophe before luck stepped in. After a long day at the track I smelled coolant, but saw no leak. I let the car sit for 3 days and noticed a small coolant leak in the back of the engine. I feared it was the head gasket. Turned out to be a another small gasket the shop forgot to install. I took the heads out at that time and installed the worked heads and that's when we noticed all the bolts were loose. Lesson learned, do it yourself if you want it done right!

 

[mechtech2]

The high performance engine rebuilders left off parts, the engine leaks, and it ticks?

Another oil is not the problem.

 

[virus]

Originally Posted By: mechtech2
The high performance engine rebuilders left off parts, the engine leaks, and it ticks?

Another oil is not the problem.


The engine doesn't leak

Some ticking is normal for LSx engines. Mine could possibly be wrong length push rods. I'm just trying to find the best/appropriate oil for my particular car.

 

[bourne]

My vote is for an 0w40/5w40 weight. Great cold flow properties with some added protection at the top end. Top of the line oils in those weights have been M1 , PU and surprisingly by popularity the ever economical oil that is the Rotella T6. But realistically , Amsoil is probably getting the job done for you just fine. Get a UOA before switching if you can. That way , we can tell if there actually is a problem that needs to be addressed here or not.