juliuskay: pls my honda accord 2004 is shortting engine oil and slow in speed after along trip . pls which engine oil should i use. the miles is 57 and there is no leakege any where. some body dhld help me pls.

aeu1: For enlightenment sake, if an approved engine oil is 5w30 for a car but in event of non availability of such decides to use a thinner oil such as 5w20 + oil treatment (to improve the viscosity), is there any danger in doing this?

Midas02:
oh boy, this thing is not as complex as some will have you believe. You do not need a degree in mechatronics and electromechanical engineering, nor do you need an Einstein to propound the theory of kinematic velocity and all kinds of useless gibberish!.

It is tooo much work to write, I am feeling lazy, however my advice:
Listen to Sultaan, listen to Siena, listen to Promise72 and the guys who concur with them and you will be fine.
Most new cars and cars after 2000 use the thinner grade of oil which is 5W-30 or 0W-40 (depending on recommendation)
However cars before this mainly used 10W-30 (recommended)
When the car gets to be over 100K - 120k miles you may move to 10W-40
If your car is really advanced in use and age and has started to exhibit signs of wear/loss of compression/smoke, then you should use 20W/50 to reduce its inevitable decline in performance and blow-by.
The most important thing is to change your oil regularly (every 3 months or use mileage) and make sure you change your oil filter too, otherwise the purpose is defeated!

I believe either the mechanics messed your engine up by forgetting to do something vital or they used adulterated oil and not the original. Cos even if you use oil that is not recommended, it shouldn't mess your engine up (especially over such a short term), it usually only affects the performance, response and long term durability of an engine. As long as your engine has some oil lubrication (whether recommended or not) it should not knock. Period!

Your query isn't clear. And I don't understand your mileage.