Hi there,

Background: Have had my MCS since October 7th. Have around 5500 (?) miles on it. Have not checked the tire pressure since I first got in it.

Yesterday I drove into my garage and noticed that the low tire pressure light was on. I checked the pressure and all were ok except for the front right which was around 20lbs low. Here are my questions:
1. Is it possible for a tire to lose that much pressure without having puncture?
2. With run flats, is there an obvious difference between a low pressure tire and a flat?

My plan at this point is to fill the tire with air, reset the light and then see what happens. (Hoping that it's not a puncture.) Is this a good plan or should I be doing something else?

Thanks for your help!

Laurie

I have a three-step, tried and true, method for getting very long service life out of tires:

1: Buy a good digital tire pressure gauge--costs $10-30. Check the tires once a week no matter what. Put it on your regular schedule (I do it when I take out the trash Thursday evening).

2: Buy a cheap air compressor and keep it in your garage--costs $60-100. Adjust the pressure as required. Doing this in your garage means you don't skip on it when the weather is lousy or when you get gas in a hurry. At 25 cents a week to pay for air at the corner gas station, a $60 compressor will pay for itself in less than 5 years. You'll also find other uses for compressed air.

3: Buy the lifetime wheel alignment from a nearby national chain tire store. From Firestone this costs a little less than twice the cost of a normal alignment. They will align your wheels FREE every 5,000 miles as long as you own the car. Bring it in every 5,001 miles!

This really works! I got 93,000 miles out of the OEM tires on my 1991 Mazda 323. I currently have 53,000 miles on the OEM tires on my 2002 Honda Odyssey (and they are famous for never lasting 20,000 miles if you read the Honda boards). I got over 60,000 miles out of the OEM tires on my 1996 Volvo 850.

No experience with the Mini runflats yet, our MCS only has a few hundred miles on it so far . . . . With the Mini you'll have to remember to reset the tire sensor button every time you change the pressure in the tires.

This is about the scariest thing I've read on this board. Scary in the sense that you could be driving the car in such a hazardous state. Assuming you have 17" wheels, your 1 tire was operating at 13 PSI? And if 16" wheels, 10 PSI? That's nuts. I'd love to know the PSI definition of your "ok" reference. Tire pressures aren't just about longevity of the tire. It's mostly about safety. Pressures as low as you've just experienced are very dangerous, to yourself and others. Anyway, your tires will always lose pressure over time, during periods of use, and due to climatic changes. You need to check them routinely, and at least monthly. I check mine about every other week and find I need to add a PSI or two. Keeping them at spec will also make driving more enjoyable, because the car will handle the way it's designed...and you'll know it's as safe as you can make it. BTW, I own a small Craftsman air compressor and a couple of quality air gauges and wouldn't be without them. It's that important.

1. Possible, yes. Likely, no. Especially if it's only one tire.
2. No. The stiff sidewalls make it very difficult to discern when a tire is flat. Virtually impossible to visually identify a low tire.

The front tires are pretty easy to check - just turn the wheel so the suspect wheel is facing out, check the surface (usually the offending object is quite visible), then move the car forward slightly so you can see the rest of the tire (use the valve stem as a gauge.) If you find an object, it's often better to leave it in for a short drive to the repair shop, as it will plug the hole instead of letting the tire go completely flat.

Alternatively, just drive to your favorite garage or tire store and ask them to take a look. If they tell you they can't patch run-flats, find one who does.

FWIW, you can get a small, cig lighter powered compressor from many stores for $10-$15.
ALWAYS have a tire pressure gauge in the car.