Pennzoil Ultra Euro 5- 40

[TEALLIFE]

Do Mobil 1, 15W-50, can't beat it unless you plan on driving in freezing weather

Thicker oil isn't necessarily better. Cold weather or not, the car is going to get close to the same operating temp. Thicker oil at operating temp (50 weight) puts more stress on the engine/oil pump, increases friction/reduces power, doesn't flow any better (which can cause increased wear and heat). Thicker oil at anything below operating temp (15 weight) is obviously even less desired.

I believe the original gen2 viper spec was a 30 weight oil (5w30?) the engine was designed for. 40 weight is as far as I'd go from the design intent (0w40 to 15w40)

Also additive break down is only really a problem in high use engines. I'm changing my viper oils long before they are getting that much use anyway. I'm not going 5k+ miles between changes, I'm barely getting 1500 miles.

Everyone has their opinions on oil and I'd bet there's not that much of a wrong answer anymore in today's market if you select a decent synthetic near the design range of an engine and change it frequently.

 

[capevettes]

When I first bought my 01 GTS about 10 years ago I picked the brain of the late John Hinckley. John was the plant manager during the Gen 2 period and was a highly respected expert in Corvette circles. The factory recommended oil for my Gen 2 was Mobil 1 10W30. John said there was no reason to deviate from that in a street driven Viper. I know oil has evolved a bit since then, but I am still running Mobil 1 10W30. I get it online from either Amazon or Walmart. I've been using the extended life formula, even though I change it once a year, about 3,000 miles.
Zero engine issues. I bought the car with 16,000 miles. It now has just under 44,000. I won't be deviating from Mobil 1 10W30.

 

[TEALLIFE]

When I first bought my 01 GTS about 10 years ago I picked the brain of the late John Hinckley. John was the plant manager during the Gen 2 period and was a highly respected expert in Corvette circles. The factory recommended oil for my Gen 2 was Mobil 1 10W30. John said there was no reason to deviate from that in a street driven Viper. I know oil has evolved a bit since then, but I am still running Mobil 1 10W30. I get it online from either Amazon or Walmart. I've been using the extended life formula, even though I change it once a year, about 3,000 miles.
Zero engine issues. I bought the car with 16,000 miles. It now has just under 44,000. I won't be deviating from Mobil 1 10W30.

yup, engines are designed based on a spec'd oil weight for the oil pump, flow, etc for a reason (for normal driving, stock engines). Once you change that weight, you're changing a lot of variables in the engine.

Modified, track, and maybe high mileage engines are different.