As Fish has said, its hit or miss on oil consumption with this generation of Corolla. Some develop the problem at some point, others never due.
My initial approach to the problem involving some hands on stuff, after getting good feedback here from Fish and a couple others: I bought the repair manual, replaced my air filter, cleaned the throttle body and butterfly valve with throttle body cleaner, cleaned the MAF sensor with contact cleaner, and replaced my gummed up 10 year old factory PCV valve.
With the mechanical stuff done, I began to explore methods to clean the engine and upper cylinder, reduce wear, and reduce oil consumption. After some research I settled on:
- Penzz Platinum 5W30 oil with 10% MMO added as a catalyst to safely clean the engine over time. PP, being a good synthetic, has the added value of reducing start up wear due to its very good cold flow properties that allow it to begin circulating and lubricating faster than conventional alternatives (this is a big bonus in the coming cold winter);
- use of PEA based fuel system cleaner at 5,000 km intervals for combustion chamber cleaning, followed by the use of upper cylinder lubricants that (theoretically) have the potential to free the rings by reducing deposits and lubricating the upper cylinder they glide along during the power stroke. My regimen is Regane for the PEA cleaner (one treated tank every 5,000 km), followed by 3 or 4 MMO treated tanks, and then TC-W3 two stroke oil (at a 500:1 mixture) in each tank of fuel until the next Regane cycle is due. MMO is thought to be a little stronger on the solvency side, and TC-W3 a little better on the lubrication side. Both have properties of each, and I view them as complementary, although I use them independently (that is, I don't treat a tank with both additives at the same time; instead I cycle them as outlined above);
- most recently, I added Lubro Moly mos2 to my oil: half a bottle initially, with one quarter bottle maintenance treatments to follow. Moly is an 'old school' additive and also a component in many (maybe all) piston ring designs. Amounts in modern PCMOs (passenger car motor oil) varies from little to none. The only oil I know that still contains significant amounts of moly is Redline, although its expensive. LM mos2 is an inexpensive additive that ups the moly count in your oil while changing no properties of it otherwise. Its called an 'anti-wear' additive as it works by plating itself to the metals present in pistons, cylinder walls, rings etc. This fills in pores and provides a lubricating film that reduces wear. As consumption in our 8th gen burners is due to failure of the oil control rings from ring "stick" and wear, mos2 shows promise in addressing both issues directly.
My approach is atypical and largely theoretical: its based on the known cause and treatment aimed directly at correcting or fixing the cause using products that show promise in this area, but for which potential results are mainly theory based (though this is also backed by anecdotal reports from others with consumption due to the same cause having reported success at reducing or eliminating it using each of these methods independently).
None of these methods work immediately or over night. Just like it took many thousand miles for the oil consumption problem to develop, some amount of time has to be allowed for when choosing methods like this that are aimed at the source of the problem, but take time for their potential effects to show measurable results.
The first of these measures (the OC to PP) was done 3,000 km ago, and MMO was added to the oil 2,000 km ago. Likewise, the additives mentioned have been introduced at different points, with mos2 being the most recent addition (about 500 km ago). I have recently observed reduction in consumption, but its too early to verify or measure. I will report back though when I have numbers to give. Note too that, as I indicated these measures take time to work, I am planning to continue with this method right til Spring without introducing any changes or further additives; although I may add an additional 8 ounces of MMO to the oil after temperatures go below freezing, to increase the concentration from 10% to somewhere closer to 15%. Meantime I will simply continue this regimen and track the results. I have additional ideas in mind as well too, but I prefer to give this approach some time to work, and to measure the results, before trying anything else.
Edit: I will add that after, probably something on the order of hundreds of hours spent researching the problem, potential solutions, and discussions with others having this issue (including many who have had success at correcting the problem and significantly reducing, or eliminating consumption), that though I have not mentioned every single possible method in this post that may reduce consumption, including the future ones I am considering after the current experiment has been given sufficient time to evaluate, that I am skeptical of the utility of Auto RX in correcting this particular problem. Very skeptical (to the point that I personally view it as an over-priced product with limited utility and whose results can be achieved through other, more cost effective measures). I will not be using it. My two cents on ARX. YMMV.