Newly Modified LS1

[sgtgeek]

Long time lurker and first time poster...Old School gearhead.....
Have a 2004 GTO LS1. Modified as follows..
Patriot Stage II Heads
Comp Cam 581/588
LSX Intake
SW Long Tube Headers
R/T Cats
Borla Performance Exhaust
Making about 400 RWHP
Pre Mod I ran Mobil 1 10w30 with no problems for the first 3000 miles.....the mods just have taken place and the tuner/wrench both have advised a good 10-40 or 0-40 synthetic like 0-40 Mobil 1 or 10-40 Amsoil. I live 25 miles north of San Antonio so if we see 20-30 degrees it is rare.....This is not my daily driver...it is a toy....maybe driven 20-30 miles a week...and yes I do play hard with it on occasion. My question.....
As the original specs called for 5-30....and I have obviously voided most of the warranty anyway.....is the 0-40 or 10-40 for performance at the expense of longevity or is the higher viscosity oil a protection/performance factor combined with the modifications to the motor? I appreciate your thoughts and/or comments......I would like to turn this car over to my Grandson in a few years...

 

[KW]

The Mobil 1 10W30 might do, but if they increased spring pressures you may need the heavier oil. Both the Mobil 1 0W40 and Amsoil 10W40 are very good oils, but I think the Amsoil 5W40 is more comparable to the 0W40. Any of then will work for you, but I think I would use either the Amsoil 5W40 or the Mobil 1 0W40 myself in that motor.

 

[Ryan00TJ]

I also have a H/C LS1. Running the Patriot Stage 2 5.3L heads with a TR224 112 cam. I have had excellent results with a mix of 4 qts Schaeffer 10w30 Blend @ 2 1/4 qts 15w40 Blend. This mix creates a heavy 30W oil and has proven to be a great match for my LS1.

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=3;t=001747

I have an analysis coming back to me now with 3K miles on straight Schaeffer 15w40 Blend I ran this summer. I will be posting it in the used oil analysis forum here within a few days so check it out.

 

[sgtgeek]

Yes we replaced the valve springs.......
Great link.....I have the AMSOIL 10w40 in now...but like I said...I only drive it a few miles a week....I'll try your "soup" and am curious of your results.....