Try the AutoRX and see how it goes. According to one post, it contains lanolin, which may swell the valve seals back to their useful size, and it also somehow scrubs your ring lands and gets rid of the baked on carbon deposits in that area. Sounds too good to be true, but everyone (almost) is raving about it, so why not?
Everyone will scream at my next comment, and you can take it for what it is worth. I use 15 W 40 in the summer in my 89 and the consumption goes down....way down. In the winter, I use 5 or 10 W 30, and, consumption is less of a problem in the cold winter months as you have probably noticed.
Prepare for howls of protests on this point, but like I said, take it under advisement.
If you are going to do the AutoRx, I would use the 5 or 10 W 30, as it will work better for that cleaning phase.