Engine issues

[RacerWC]

Personally I don't know a huge amour about engines so the question below may seem very noobish

I seem to be chewing through a lot of oil ATM then again I am doing 1000km a week and I seem to have a fine black powder coating the rear end of my car I assume this is the oil coming out the exhaust.

What's likely to be causing this? Is it expensive? Also car does seem to be using more fuel lately too

[mko]

What oil and weight are you running? What octane fuel are you using? How many miles on engine?

[Galanttuner10]

Black on the bumper. Seems like you are running rich as that happens to turbo cars which we tune rich for safety reasons. That on the bumper and fuel consumption issues seems like it's running rich which could be a failing front oxygen sensor that controls the air fuel mixture and is the most common failure especially if it runs almost like normal just burns more gas.

[RacerWC]

I'm using valvoline engine armour of memory 15w40 orange bottle but will check when I am home 91 octane which is what my owners manual says I must use. And the miles is 361000kilometer not sure what that is in miles but its a lot.

Car is running same as normal just using a little oil and using extra fuel although my electronic idle control well I think it's called that needs replacing

[mko]

15w40 is too thick and it isnt what manufacturer recommends. 15w40 would slide off the cylinder walls much slower which would increase the possibility of oil passing the oil rings on the pistons. Not to mention that thicker oil will create more oil pressure and make engine work harder which equal to bad gas mileage.

Another thing is the valve stem seals. Cheap part, but its hard to replace.

[Galanttuner10]

I ran 15-40 Rotella in my car for years no smoking or any other issues. I know it's not the recommended weight but because mitsus tend to run so hot you really won't hurt anything. And like he said he is looking at black on his bumper like the car running rich not a plume of blue smoke which he would nothing if the rings were going or the valve seals were

[RacerWC]

All the oil manufacturers recommend 15w40 for my engine so that's why I am using it. I've been using the same oil for 6 years kin all my cars and no I don't have any blue or white smoke. And I am starting to think its only using a little oil but that could be due to the sheer amount of km I'm doing 10000 in a month. Or because car running rich

[eksz]

FYI: 10,000 Km = 6,000 miles per month. What are you doing that you log that kind of mileage each month
in New Zealand? There must not be a mile of road in either the North or the SouthIsland you have not driven.

[RacerWC]

Yea travelling a lot for work delivering parcels and visiting high profile clients ATM. Well my oil and filter are due again must do that as soon as I home again