I just had a oil change (used Lucas Synthetic.) , now if I want to top up my oil inbetween oil changes should i use the exact same oil or can i use any synthetic oil of the same weight? Or only use a different brand in emergency situations?

 

The container that the oil came in ought to answer your question. However, I know if no synthetic oil that is not compatible with petroleum oil.

Ideally, you ought to use the same oil for additions that you use for the fill. But, it will do no harm if you use either petroleum based oil, or some other brand of synthetic oil, for additions. You ought to always use the same viscosity (or weight).

Here is a question to research. Does the 'W' in 5W-30 represent 'weight' -- or does it represent something else.

 

why do you need to top-off your oil- Does your car burn oil- I never had too after 71,000+ miles.

 

The "W" represents "Winter", meaning the oil has an acceptable viscosity in lower temperatures.

 

you can mix oils.
I wouldn't, there is no reason to.
just buy extra of the oil you use.

and yes, the TSX is very known for having oil burning issues
in some cars. many say it is the cars that were never broken in
properly, and many others say they were just built wrong from the factory.
Acura has replaced several oil burning engines in TSX's in the past.