Try Pennzoil High Mileage, It helped me on my 98 Toyota with almost the same amount of oil consumption you are dealing with. I now add 3/4 of a quart at the 3,000 mile mark. I run 4,000 mile oil change intervals. It took about 8,000 miles/ 2 oil changes for me to notice the results. I'm sure other high mileage oils will probably do the same as well.