Originally Posted by Scotto97
I just purchased an SRT roadster from a private party and found a receipt from an oil change shop that shows synthetic 5-30 was used. This was not an oil change done at the dealer. It took place 2 1/2 months ago and 3,000 miles ago. Will I be ok with this different rated oil, or change it out ASAP with Mobil 0-40? I live in Las Vegas and it's still very hot here. Thanks.
If it's fully synthetic it should be okay. I was talking to my petroleum engineering friend and said there isn't much difference between 5w30 weight and 0w40 weight oil, just a slight difference when in cold temperatures. The kinematics viscosity is slightly different at 100 degrees celsius for each oil, but I wouldn't worry about it.