It has close to 195,000 miles, but only one other owner than me. There are no leaks of any kind under my car, and there is no smoke coming out the exhaust. I try to get BP Amaco fuel, 87 octane. I just had an engine light come on and had it deleted for cylinder misfire on 2, 4, and 6, and since then it has never come back on(about a week).
Need more information, please post your mileage, any engine maintenance that has been performed, that is due, or over due. Have you had any check engine lights recently? If so, what codes? Also, what gas octane and company name are you using?
Some of the things that could be causing this are:
1) Cheap gas
2) Knock sensor(s) going bad
3) Spark plugs need changing or were replaced with non OEM Denso or NKG's. This engine has a tendency not to like non OEM iridium plugs.
I had similar problems and after a few months of trying various grades of gas companies, octanes, cleaners, etc. I started to get the P0330 code which is a knock sensor. I also changed back from Bosch Fusion plugs to OEM Denso IR and that helped some.
As for the oil consumption, are you having any smoke coming out of the exhaust? If so and it's blue that is a problem. Pull the front engine valve cover to rule out engine sludge. These engines have a history of making sludge and have a 8 year warranty on they via a class action lawsuit. Also check the ground and undercarriage for leaks. If it's not being burnt it's coming out of the rear main seal, crankshaft seal, or some where else.