Engine oil to use on 2007 Silverado Classic

[subgenius]

I'm not close to changing the oil yet on my new Silverado, but was wondering about oil recommendations. Previously owned a 94' Silverado with the 350 engine and used pennzoil 10-30 and never had problems. In the 2007 owners manual Chevy recommends 5-30w only. On the forums here I've read most are using Mobil 1 synthetic. I plan on using the 5-30w oil, but was a little concerned because I live in Phoenix where 110-115 degrees in the daytime is nothing unusual for this area. Does the 5-30w offer the same protection as 10-30w? Is there added protection of using a synthetic over natural oil in this high heat?

[cerbomark]

10-30w will not help with the heat. The first # 5 or 10 is the low or cold end #. The 30 is the heat end #. So a 5-40 or 10-40 is for additional heat. Check in the manuel or under the hood. I think 5-30 is still recommended for your application. Use a synthtic oil (mobile 1) if you want added protection. The newer engines are made for the thinner weight oil for max efficency.

[ZZebes]

I used Pennzoil Platnium 10W-30 Full Syn and it is working wonderfully

[mdub]

Compared to 5w-30, there is more actual lubricant in 10w-30 (due to less need for viscosity improver). In those temperatures, stay with 10w-30 engine oil -- there is no need for 5w-30, especially if you're driving a lot of highway miles.

 

Many (myself included) use 10w-30 in the summer, and only switch to 5w-30 in the winter if the temperature routinely falls below ~30°-40°F. In your location, your engine would likely benefit from 10w-30 year-around.