If the filler cap for a 1992 Chevy van with a 305 say to use 5w30 oil is this right?
Oil viscosity is dependant on manufactures tests. This is fine for your engine I used to use 10w-30 now I use 5W-30 the 305 likes the 5w-30,it has more pep and gets better milage. I live in TX. I have a stock '87 Camaro LT with the 305 & 4BBL Carb. and Auto Transm...I bought my Camaro with 99,000 miles on it 8 years ago and I have used 5W-30 Oil in the mild North Central Idaho winters and straight 30 in the summer time, until now. I will continue to use 5W-30 all of the time now. No reason in partucular other than maybe the price of the oil and will perform more frequent oil changes (3 months versus 4-5 months). 5w-30 will work fine in your van
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