Hi All,

Possibly a basic question, but how can you work out what exhaust size you have i.e. 2.5" or 3"?

Is it purely the external diameter of the exhaust? Does it have to be measure at a specific point in the system?

 

Depending on the system it may change in diameter at different points.
Measuring the outside diameter will tell you if it is 2.5" or 3".

 

just put a tape measure against it not round it and will pretty much be one or the other

 

Thanks all.

I guess by against it you mean measuring the diameter rather than the circumference?

 

yes it should be obvious what the size is