We have 3 cars and I would like to use the same (mobile 1) oil in all of them. The civic and 4runner both call for 5w 30 and the jeep calls for 10w 30. I am just not sure if I would have in problems down the line from running the 5w 30 in the jeep. the jeep has about 100,000 miles on it and it might get 5000 miles a year put on it.