What is the capacity of asthmatic lungs vs non asthmatic lungs?

Depends: Asthma is an obstructive lung disease- difficulty getting the air out. Many asthmatics have normal lung function at baseline and only experience symptoms and diminished lung function episodically. Some asthmatics do develop fixed changes in the airways, called airway remodeling. These changes can range from mild to significant.

Depends: Estimated peak flow is based on age and height. Usually it is approximately 450 l/min in a non asthmatic.

Lung capacity/asthma: Total lung capacity is the volume of air in the lungs at the end of maximal inspiration. Asthmatics can have higher lung volumes than normal people because their lungs become hyperinflated when they have attacks. They have trouble breathing all the way out, so the volume left over afterward, the residual lung volume, is also elevated. In severe asthmatics, fibrosis/scars can decrease volumes.