Best oil viscosity for extreme hot climate

[mahma1]

Hi,

I'm new to this forum. I own a 2008 GM with 3300 mi on it. Most of my driving is highway (85%), the rest is city's. I was wondering what would be the best oil viscosity to use for a climate that reaches 115 F in summer and as low as 65 F in winter. The owner manual says I should use 5W-20, and it's printed on the oil cap on the engine block. I'm not sure that would work here in Riyadh, Saudi Arabia! I didn't find any where in the manual, even under Special Operating Conditions, the type of oil viscosity that's available for the above temp! I've researched a lot, and I mostly found through reading that 10W-30/10W-40 would be appropriate for hot climates. I've also discovered in other forums (not Ford) that 20W-50 would be appropriate. However, I tend to lean more to 10W-30/10W-40 types, especially as these are always mentioned and recommended for today's modern vehicles. I'm still not sure how to go on this, and would like to invite your enlightening comments and suggestions.

I'd appreciate your input.

Thanks,

Mohammad

[way2old]

Go with what is recommended by the manufacturer. 5W20 should do fine.

[mahma1]

Thank you for ur efforts.

I've contacted Ford dealership a copla days ago; the manintence supvsr told me they use 10W-30 for all ford and merc vehicles, I thought I'd share for those with similar or near similar Hot Climate conditions. Further, the local dealership here in Riyadh provides a supplemental booklet for cars in the Middle East to use as guide for oil viscosity usage. I quote from page 3 in the booklet, "Use SAE 10W-30 engine oil certified for gasoline fueled engines..."

[garrytoao]

Originally Posted by mahma1

Thank you for ur efforts.

I've contacted Ford dealership a copla days ago; the manintence supvsr told me they use 10W-30 for all ford and merc vehicles, I thought I'd share for those with similar or near similar Hot Climate conditions. Further, the local dealership here in Riyadh provides a supplemental booklet for cars in the Middle East to use as guide for oil viscosity usage. I quote from page 3 in the booklet, "Use SAE 10W-30 engine oil certified for gasoline fueled engines..."

i use 5/30 multi blend in my 00 gm 56,000 miles never had a problem with knok or valve noise