Originally Posted By: Bullet
My wife has a 1996 Avalon. Three years ago one day she calls and said her car smoked. She had the oil changed at a jiffy lube. That night I changed the oil to three quarts 10w40 and two quarts 20w50 maxlife IIRC. After that I used 15w40 Rotella until recently after I found it has consumed one quart in about 1600 miles. This time I put 20w50 penzoil. I always thought it the valve stem seals. Anyway we use it as a spare car putting about 150 miles a month. Sometimes a little more/less. I never heard of the low tenson rings. I did run a couple RX a couple of times, but just never went back to 5w30. Maybe I'll try something in the oil like MMO.
I'd recommend studying up on Schaeffer's Neutra 131 instead of MMO. Neutra can be used in the fuel (see Mokanic's post above) and in the oil - typically should be used for the last 500-700 miles of an OCI. It's chemistry does a slow clean - unlike, and very likely more effective, than Seafoam, and the quick flushes. Or go with the Auto-rx. But I don't think MMO is going to do much for you - I've had quite a bit of it in my crankcase on two occassions, and I use it pretty regular in the gas of my Sienna - can't say it's done anything.
Meanwhile, I did a couple of runs (way back) with 131 in my '98 Sienna's crank case and in the gas. Saw improvement in consumption - perhaps by half. The van started seeing fewer miles (secondary vehicle) so I didn't bother staying with it. However, this summer it's going to see perhaps 4-5k of hard vacation miles - so I'm re-invigorated by Mokanic's post to start pushing the 131 thru it - cause consumption is still an issue. Will likely make a lunch time run (a long one) to my Sch. distributor tomorrow and get a couple of gallons. BTW, Neutra is very economical - last time I bought some it was $16/gal. - and that goes a long ways. I'll keep it running all summer in the gas tank and for the last 1k of my OCI (which I'll now shorten to the end of summer).