should I use. I use Mobil 1, what should viscosity I quess it is called in it? 5w40, 10w30, what ever those numbers are, what one should I put in the car this winter.

 

I suggest 5W30.

 

brgjag, because you have a 97 Jag, for winter, use of 5W30 will be the best choice. Thick enough to coat the surfaces well but not so thick when it is cold that it can't flow easily. If you had a new car, then that would be a different story. The newer motors have even tighter tolerances and require a different grade oil.

 

thanks folks! What should I have been running this summer??? Just curious as the shop changed the oil when they did the tensioners and I do not recall what they put in it other then it was Mobile 1.