Soooo I've had my s2k almost 2 months and the tire pressure is really starting to irk me. I had a nail in my left rear a few weeks ago and it was plugged and okay, but all of their PSIs seem to be dropping at similar rates, more so in the rear though. The temperature has been fluctuating quite a lot since it's winter in the north east and dipping into the teens some nights, but I drove 80 miles (tripometer) and they are down to 27.5 PSI tonight. Incase it matters, they are the stock Bridgestones and I'll be switching over to Blizzaks in the coming months. Should I put nitrogen in those? Thanks, guys!

Off topic, but the car is absolutely amazing overall and I feel extremely fortunate to be an owner after 11 years of waiting

 

My old tires had dry rot and would leak air all the time, I must have plugged them 3-5 times each. They aren't old are they? Remember tires can go bad before they ever get enough mileage on them. Stuff like little rocks and pieces of metal would pierce my tires because they were so old.

Careful out there, I've lost the rear a couple times with my old dry rotted Kuhmos. My new Kuhmos are perfect though!

 

The rears were practically new with very little mileage on them. The ones in the front are dry rotted, so I guess I'll just have to keep an eye on them regularly. At least I found a place with free air instead of paying .75 a week since they'll probably continue at this rate. They won't be on too much longer anyway probably, so I guess I'll have to fully deal with it this upcoming spring. Thanks.

 

Your pressure drop is probably normal. As the temperature of the air in your tires gets colder, the pressure drops. You can calculate the exact pressure drop with temperature using Boyle's Law. And if you check your tire pressure after a long drive it's going to be higher than on a cool morning after being parked all night.

 

Yep I am having to fill my tires pretty frequently too - like every 3-4 weeks but thats probably normal. I was spoiled by the mazdaspeed3 - the tpms NEVER went off on that car as I checked them every month and rarely had to fill/drop tire pressure as the weather changed. Its a lot different with the s2000 for whatever reason. Tires perhaps? The tpms keeps lighting up but courtesy of the dealership where I got my car used they +1'd the front tires and left the rears stock lol.

 

your valves could be loose, i know its small but is sometime looked over