Those who have had good results with MMO report that it takes time to do whatever it does.
You say that you now see no black smoke on upshifts.
What about a reduction in oil use?
If I had your car, I don't think I'd go to the expense of using Mobil 1 High Mileage, since I'd be doing some short drains.
I think I'd use a cheap, decent dino, like Peak or Quaker State, and try a few short, like 3K, runs of one of these oils with MMO added for the last 500 miles or so prior to the oil change.
I'd probably use a 10W-40 to counteract the thinning of the oil caused by the MMO.
Since you aren't in any way attached to MMO as a miracle additive, as are some on BITOG, you could give a very objective account of what it does or doesn't do in your car.
This would be valuable to many on the site.
I don't think that you have an engine that's easily hurt.
This car would be a Sephia, right?
From what I've read, while these aren't known as having been the most reliable cars of the 'nineties, actually among the least, the engines are solid and not at all fussy about little things like oil.
M1 does seem rather costly for a car that's using oil.
This is a low mileage car for its age, though.
Did this thing sit unused for a fair amount of time?
It may be that the rings are freeing up merely through your driving the car, particularly if it's a stick, as I'm assuming it is from your discription of shifting it.
In any event, good luck, and keep us posted how it goes.
You say that you now see no black smoke on upshifts.
What about a reduction in oil use?
If I had your car, I don't think I'd go to the expense of using Mobil 1 High Mileage, since I'd be doing some short drains.
I think I'd use a cheap, decent dino, like Peak or Quaker State, and try a few short, like 3K, runs of one of these oils with MMO added for the last 500 miles or so prior to the oil change.
I'd probably use a 10W-40 to counteract the thinning of the oil caused by the MMO.
Since you aren't in any way attached to MMO as a miracle additive, as are some on BITOG, you could give a very objective account of what it does or doesn't do in your car.
This would be valuable to many on the site.
I don't think that you have an engine that's easily hurt.
This car would be a Sephia, right?
From what I've read, while these aren't known as having been the most reliable cars of the 'nineties, actually among the least, the engines are solid and not at all fussy about little things like oil.
M1 does seem rather costly for a car that's using oil.
This is a low mileage car for its age, though.
Did this thing sit unused for a fair amount of time?
It may be that the rings are freeing up merely through your driving the car, particularly if it's a stick, as I'm assuming it is from your discription of shifting it.
In any event, good luck, and keep us posted how it goes.