I struggle to find filters for my a/c because it’s a common dimension

Sometimes I struggle to find the right motor oil for my car whenever I’m at the auto store.

Apparently the particular genre of oil that I purchase is 1 of the most commonly used motor oil varieties that are sold to the public.

It’s the common option for a slew of sedans from multiple competing brands. Because it’s so widely used, it often is out of stock at the store. I usually always bought my auto supplies at the auto stores, however now I’m ordering them off the internet by necessity. The last thing I ever want is to find that I’m low on motor oil when checking the dipstick and not have any oil on hand to top off the engine. I’m afraid of what could happen to my engine if I ran it for too long while it’s low on motor oil. I deal with a similar situation regarding my cooling system. As much as oil is an essential in cars, air filters are essential for central HVAC systems. My cooling system wouldn’t have survived nearly as long as it has thus far if I had neglected filter changes. Unluckyly, my filter dimensions are 18 inches by 18 inches, which obviously is an severely common filter size. I do not like going to the store for a new cooling system filter only to discover that none are in stock. Air filters aren’t as easy to find on the internet as motor oil, so in the end I’m forced to visit more than 2 stores until I can find a filter for my cooling system. I don’t want to go long without a new filter and cause damage to my cooling system. I’m just going to have to buy HVAC filters in bulk from now on.

Cooling and heating provider