What weight sythetic oil for 2002 Elantra?

Just bought a 2002 Elantra GLS with only 15K on the clock.

I have used Mobil 1 in all my cars for the past ten years.

What weight synthetic are folks in this group using in their Elantras in
desert temperatures(Arizona)?

The owners manual actually refers to three different climates with several
oil viscosity choices for each climate. My drive to work is 35 miles. The
return trip home is about 18 miles up a steep grade which leads through a
pass. This "hill" takes out vehicles almost daily. Some blow hoses, some
overheat badly and motor homes catch fire because this time of year the
temperature hovers around 110 deg in the afternoon.

I picked up a case of Mobil 1 15W - 50 this morning but after giving it some
more consideration I called Mobil. They thought Mobil 1 0W - 40 would be a
better choice as they felt 15W - 50 was overkill for a 2.0 Liter 4 banger.
They also suggested that 0W - 40 would give better gas milage.

Any opinions or experience would be appreciated.

Thanks

Paul

 

It's interesting that this link from the Hyundai Web site states that 15W -
50 is OK for my temp zone.

http://www.hmaservice.com/webtech/iindex.asp?id=394878893#_394878893

 

The dealership in my town (Courtesy Motors, Lafayette, LA) actually
recommends and uses for their oil changes 20-50 oil. The climate here is
hot also, but maybe not as hot as AZ. Even still, it seems a little heavy
to me, so I settled on 15W-40 semi-synthetic Castrol. Seems like a good
weight for me---