My Jeep has a 4.0 in it with 130,000 miles. The guy that had it before me said he was having it changed at the Valvoline oil change place and that he had switched it to the high mileage oil. I've been changing it and using the Max Life Synthetic Blend figuring that is what they were putting in it when he had it changed. I just wanted to get others opinions on what intervals they are using? I like to change my oil at 3000 miles but with the synthetic blend I figure that may be overkill since pretty much all of my miles are highway. I was thinking more like 5000 miles.