Went to enterprise and rented a car that had literally 4 leaking tires and they filled them all up to 55 psi before handing the car over. This photo was taken after the 30 minute drive home.
Called and took the car back in for service only to get the same car, same 55 psi on all wheels, and same major leak in the rears. Went to another enterprise location to get a normal car instead 2 days later. Really took me back to my first car, but it’s a lot less fun when it’s not even yours and the “fix” is just dangerous overpressure.
In warm weather, it might last all summer. In the winter, I can go maybe 3 months before the low pressure warning comes on. I’ll get new valve stems next time I get tires. For some reason, that hadn’t really occurred to me.
Some rims are slightly wonky, which can also be exacerbated by temperature fluctuations, with the rims getting a bit larger or smaller. I had a problem like this, and used an air compressor plugged into the cigarette-lighter outlet to pump up the tires from time to time.
Yeah, I’ve got my own pump too. Great purchase.
Some of these newer alloy wheels are harder to mount. If you let them know there’s a history of leaks on that tire they may apply tar to the rim which can go a long way. My car has had a lot of issues on one tire until I found the right mechanics, ironically they were also the cheapest (small business who specialize in used tires). Later after getting new tires the problem went away without the tar, so I think it comes down to surface prep.
You could try tightening the valve core too. But 3 months isn’t really a slow leak. You should probably fill your tires that often anyways