I bought this to keep my tires at the appropriate pressure - especially in the fall when cold temps reduce the pressure in the tires. The cord is long enough so I can do all for tires on a Honda Accord (2018). I have a digital tire pressure gauge so I compared its pressure reading to this unit and they were within half a pound of each other. The reason I took off one star was that the unit is a bit awkward to use. Especially screwing the unit onto the tire valve and removing it. A clamp-on connector would be far easier to work with. The unit is not particularly fast at filling the tire but I never had to wait more than 3 minutes. I would not recommend this if you want to maintain several cars at the same time (it can get hot after 3-4 tires). But it makes the job of keeping tires at the optimum pressure much easier and at a reasonable price. It is also small and it can fit in a glove compartment or be kept in the trunk if needed (I just keep it in a drawer in a desk near the garage).