10w-30 is for higher mileage engines. So it depends on your mileage. If it's "normal" for the year or your car, go with 5w-30. Only diff is 10-30 is slightly thicker. Doesn't really matter when it comes down to it. Just pick one and stay with it. 
Simon W. Las Vegas.
96 SE V6 MTX Tereador Red (1st Blown Engine, better be the last!)
1999 SVT Engine
SVT Exhaust w/custom DTM Tips and optimized Y-pipe and no Res (thanks to Po-Jay!). LSD Quaife(thanks to Terry!), SCA CAI w/KKM, Grizzly clutch, FMS 9mm wires, Airknights custom short shifter.
"You can only get more rice at one time by ordering Chinese" - Davo7SVT
"it's only nuts and bolts" - Terry Haines
"Drive it like you stole it" - Me!
| 
