What Oil for N/A 2.3?

[bigdaddy]

So my sister has a 2005 Mazda 6i Sport, and I was wondering what type of oil to go with. Since she's in college, she has to go a little ways between oil changes, so I was thinking of going full synthetic to lengthen the life of the oil.
I run Pennzoil Platinum 5W-30 full synthetic, should I do the same in hers. My engine is obviously different, but I just wanted another opinion.

 

[tunersteve]

PP will be just fine for the engine. Motorcraft will work too, since that's what Ford recommends for the same engine in the Fusion/Milan/MKZ. I don't know exactly what viscosity they recommend for the 2.3 N/A though.

 

[bigdaddy]

I think they recommend 5-20, but 5-30 shoudnt hurt, right?