I have a 2004 Chevy Express Cargo Van
that has the 4.8 L engine, and is a HD rated 2500 version.
The vehicle is being used for construction use, and has about 65,000 miles. Lately its been about 90 degrees here in NYC, and I feel as if the engine is getting to hot, and the car is not driving quite the same. I know on 80's older cars usually at about 70,000 miles I used to go with a 10w-40, and things were fine. However I know engines have changed.
I was wondering, what type of oil should I use for summer, and should I use the 5w-30 in the winter?
Or should I keep the oil the same throughout the year?