I'm aiming to get an oil change sometime this month, and I've got ready access to a dealer that can get me AMSOIL products. I'm debating as to what grade of oil I should use.

I want the car to be balanced and ready to endure any situation my environment can throw at it at the drop of a hat, whether it be stop and go, trademark Seattle traffic, the occasional stop light race, whatever. Will 10W-40 suffice, or should I go with 20W-50?

I will use their engine flush product prior to the oil change, and will use their oil filter.

Car's in the sig.

Thanks for any help you can provide!

Jason

 

What climate are you in? and why aren't you considering 10w30

 

I've been using Amsoil 10W-30 on the street year-round, and their 15W-40 on the track. Generally speaking, smaller spread in viscosity is better...less whacko molecule design to coil and uncoil as temps vary, therefore more resistant to shearing.