Oil consumption

[Matt97]

I have a motor repair shop and find that straight SAE 40 oil works wonders for minimising leaks and reducing engine noise on older vehicles. Bear in mind that i am in South Africa so low temperatures are not an issue .On one of my personal vehicles ,Mazda 323, B3 engine i found that using 20W50 and `15w40 oils would have the dipstick showing on the min level every two weeks ,this started happening when the car reached 200 000km .Started using Magnatec 10w40 and this has stopped ,oil consumption over 5000km is now minimal, not even showing on the dipstick . How is this possible ? The Mazda B3 engine was designed in the eighties and only calls for a basic 20w50 multigrade oil .Magnatec is Champagne to that motor! Any views as to why the sudden improvement in oil consumption ?

 

[bmwtechguy]

Some oils just work better than others in a particular engine. You found one that works! Stick with that one if it is cost effective.

 

[skyactiv]

Some of the oils you used may be low quailty group I oil with very high noack volatility and/or the better oil cleaned up the piston rings if they were sticky.

 

[JMJNet]

It is a process called "Aging". I know it is a machine but they do age, the metal wears out, tolerance is going out, etc.

 

[Linctex]

Originally Posted By: skyactiv

Some of the oils you used may be low quality group I oil with very high NOACK volatility and/or the better oil cleaned up the piston rings if they were sticky.

This is my thought. Sometimes, a high quality oil can fix several problems.

 

[Matt97]

Previous oils were Total and Shell multigrades .Must add that the car never visibily smoked yet you could see the evidence in the tailpipe of oil burning