Maverick1125

Checked the tire pressure last week when I bought my car and one rear tire was down to 10psi and the others were down to the low 20s psi. I checked them today and the low rear tire is down to 13psi and the others were down to the low 20s again. They all can't be leaking can they?

The tires on the back are 305/30/19 Bridgestone Potenza RE-11. Is that too big for the stock rim? Should I just go to 285? I don't plan to track the car.

Anyone recommend a good tire for daily driving and commuting?

CadVette

Was it a cold day when you checked the air pressure? Outside temperatures can affect tire pressures a lot. A 20 degree day will show a noticeible difference as to checking the pressures on a 100 degree day. Also makes a difference if you check the pressure when the tire is warm after driving. I make a habit of checking and adjusting pressures when it turns cold. You may have a leak on just one tire. As long as the bead is seated correctly on the wheel for your oversize tires or you haven't worn a hole in them scraping on anything you may be o.k.

J3TVETTE

I like to use Firestone Wide Oval RFT. Good tread ware rating and they are run flats. I have friends with 305 on the stock wheel and no issues. Valve stem leaking? Are you checking the air using a tire gauge or using the gauges in the car?

Vette_DD

Recent post by someone indicated they had a slow leak caused by a loose nut on the air valve stem on the tire.

acrace

Could be corrosion or minor surface defects on the rim flange. I had a similar issue with a 2010 Malibu that I bought used in October (bought it from a buddy who told me what was going on). Had my favorite tire place dismount the tires, clean off the rim flanges, remount the tires, and they've been fine.

I'd check the valve stems, as previously suggested, first as that is the least work.

BTW, the rough rule of thumb is one psi decrease per ten degrees of ambient air temperature decrease.

extrapilot

You could check the max air pressure for the tire on the sidewall, inflate, get a water sprayer and check around the rims/bead area and valve stems, taking the caps off also, checking the stem cores for leaks as well. The down side is, 1) if it's freezing outside water may freeze before you can see anything leaking, 2) going to be hard to check the inside bead area when mounted on the car.

Josephcat

Just curious , do you have after market valve stem caps? reason being is that if tightened to tight the O ring inside the cap could press against valve relief and let air out. Talkin from experience here!! lol

Maverick1125

Thanks for the advice on the valve stems. I didn't realize they were different and screwed in and not just popped in like a regular wheel. I'll take the car in and have them check for leaks for that one tire. The others may just be the temp.

Do must tire shops like Discount tires know how to handle Corvette wheels and valve stems and how to jack it up?

Maverick1125

I don't know how to tell if they are after market. This is my first Corvette and I'm learning as I go/

Josephcat

just take off the cap and inspect the inside of it. I purchased mine with the Vette flags on them and when I replaced my tires a few years back. Next morning I walked into garage and found flat on my brand new Nitto's! After hour of inspecting for nails etc and pouring soap water on it while using every swear word that I had ever learned ,
my wife walks into garage trying to calm me and after a few minutes she picked up the valve cap and asked me "what is this black thingy inside"??? Bingo!!!!

Maverick1125

Another thing. Last week when I checked the tire pressure they were at 35psi accept for the one low one. I checked inside the drivers door frame and it said it should be 30psi so I lowered the pressure on all the tires to 30psi. Should I put them back up to 35 psi?

AORoads

You do know when to check the tires, right? First thing in the morning or when the tires are cold, not heated up from a ride. Heated up tires can rise as much 3-5 lbs. in your area which, per the lack of info in your profile, we have no idea if it's currently 40 degrees or 80 degrees.

nzkiwivet

A friend of mine had an unexplained slow leak on his C5,after alot of checking valves etc etc it turned out to be a cracked wheel.This would probably be a fairly rare thing but worth considering?

NashvilleGrandSport

I had the o-ring in the cap let the air out of one of my tires after having my new wheels installed at Discount Tire just this week. Got it home, realized the issue, pumped up the tire with my plug-in compressor and good to go. Aftermarket valve stem caps.

John Harry

That seems to be fairly common. They can also leak if the nut is too tight. Torque spec is 62 in. lb., which isn't a lot.

09LS3

You, did not say what wheels you had.
I was chasing leaking tires for a while, it turned out that my chrome gumbies were corroding where the tire bead seats on the rim. This seems to be pretty common with chromed aluminum rims; especially if you drive the car.

Maverick1125

It looks like the wheels are polished aluminum. I spayed soupy water around the outside bead and the valve stem and core and nothing was making bubbles. It's losing about 2 psi each day. The leak may be too slow to bubble up. Not sure what to do next but take it somewhere and have them find it.

It seems this is a common problem now and very frustrating. Since there is no spare tire it sits in the garage until I can drive it to a local tire shop.

Larry Myers

Pump it up and drive it to the shop.

Maverick1125

That's the plan.

Arkyvette

I too have one rear tire on my 08 with a stubborn leak of about 2 psi per week. It is how I learned that my rear wheels are programmed backwards on my tpm....I was hoping when I get new tires here in a few weeks that it will go away. Probably not a bad idea to check these valve stems while they are apart though. And have them programmed properly.