I was thinking of runing the Shell Helix Ultra Extra 5W-30 spec's are below. Currently running Mobil 1 5w30, best oil I have had in Commodore V6 3800 (1996 engine), very quite, smooth and free revving. Except its drinking it a little too much.
It seems to be best oil I've had in there except for the increase in consumption. I think its primarily due to the low tension piston rings used in the 1st series of ecotec V6 motors.
I figured a XHVI group 3 oil may slow it down. Moribundman in another thread spoke about Group 4 oils were consumed at a high rate than Group 3's in some engines. I'll try the Shell Helix 5w30 first before switching to the Shell Helix 5w40.
Shell Helix Ultra Extra 5W-30
ACEA: C2/C3 (A3/B4)
BMW Long Life-04
Mercedes Benz 229.51
VW 504/507
Chrysler MS-11106
Fiat 9.5535 S1 meets requirements
Porsche C30
PSA B71 2290 approved
Typical Physical Characteristics
SAE Viscosity grade 5W-30
Kinematic Viscosity ASTM D 445
at 40°C mm2/s 67.9
at 100°C mm2/s 11.8
Viscosity Index ISO 2909 170
Density at 15°C kg/m3 ASTM D 4052 0.848
Pour Point °C ISO 3016 -39.0