Tire Pressure

My 1998 BMW 540i owners manual states that I should check the tire pressure EVERY 2 WEEKS!

Mind you, I don’t mind checking the oil every 1,000 miles, but, truthfully, I long for the days in the 50’s when you could pull into a “service” station and several handsome blokes would appear at your beck and call to pump your gas, wash your windshield, check your oil, and yes, check the tire pressure.

Gee, what’s the easiest way to accomplish this directive in '08?


Buy a tyre pressure gauge. You can buy a good one for a few dollars, although there are better ones.

Most of the time you will not need to add any air.

First, I want to congratulate you on reading the Owner’s Manual. Far too few people are aware of what is contained in that important little book, as evidenced by the predicaments in which many people put their cars and themselves.

As to the tire pressure, I would suggest that you buy yourself a good quality tire pressure gauge–either a dial-type gauge or a digital one. Avoid the “pencil” types as they too often lack accuracy. Check the tire pressure either before the car is driven in the morning, or before you have driven more than a couple of miles at low speed, in order to get an accurate reading of the pressure. Driving for more than a couple of miles at low speed will raise the pressure of the tires, and will produce an inaccurate reading of the pressure.

If you want to really do things properly, you should also get a tire inflator that can be plugged into your cigarette lighter. That way, you can check the pressure at home, as well as take care of any inflation issues at home. Additionally, if you carry this in your trunk, a tire puncture on the road can be temporarily ameliorated, allowing you to get to a garage for tire repair. It might be necessary to stop and reinflate a punctured tire a couple of times on the way to a tire repair facility, but this is still less strenuous than mounting the spare tire. Too often, the air pumps at gas stations are blocked by parked cars waiting for service, and of course, many stations charge a fee for the use of their air pump. If you buy your own inflator, you will have a very convenient little appliance.

Yes, back in the '50s, it was possible to have a station attendant check your tire pressure, but who knows how conscientious the attendant might have been with that task. For truly accurate checking of your tire pressure, nobody will be as interested in this task as you, the car’s owner, will be. And, in the process of checking the tire pressure, you can also see if there is visible damage to the tire sidewall and you can observe whether the treads are wearing evenly, thus giving an added benefit to checking the pressure yourself.

Do what these folks suggest. The only way to get good pressure numbers is to check it yourself before driving. Once you do that a few times you’ll get a good feel for how often you’ll need to do it.

Check your tire pressure and oil level every few fuel fillups. Your car and tires will last a long time.

Most BMW entusiasts just love forever poking around their cars.Really if your going to drive a car hard (you own a 540, maybe its a stretch to conclude that you will drive a performance car hard,but I am going there) you need to “pre-flight” your car more often.

You’re already one in a thousand having actually read the owner’s manual. By setting out to check your tires another important step gets accomplished that, again, maybe one in a thousand people ever do. You get to see the right side of your car ! The “pre-flight” inspection of one’s vehicle is rarely performed and by checking tires you are at least seeing the condition of the treads albeit not pre-flight but you’re seeing a lot more of the right side of your car. Also, once in a while, have someone else sit in your driver’s seat and work all the lights and signals while you inspect from the outside.

Every two weeks is overkill in my view. I check mine every month or two. Chances are that you will feel a low tire in your steering. An occasional visual check is good too; will find a radial tire that is grossly low in pressure.

You might want to try those pressure indicator valve caps from a car parts store. I don’t know if they are good or not.

Ha, if I drove this car hard, I’d probably get ticket (LOL)!
Truly, I suppose for everyday it’s less critical, but I can see that if I want the best performance from my car then the “pre-flight” is critical.

Every two weeks makes sense if you have low profile tires. They don’t hold as much air as taller tires. Lower volume to surface area ratio.

Be aware of seasonal temperature changes. A 9 degree change in ambent temp will account for a 1 psi tire pressure change.

Good point. We have P235/55R17 on one car. They get checked once per month, if that often. Possibly you mean really low profile.

I have pressure indicator valve caps, they are ok but I caught one leaking out a slight bit at the place the plastic window fits into the metal stem. I epoxied it and should really check it now to see if the glue is holding up.

It’s shades of gray. I would be more attentive of a 55 profile than a 70 profile.

Same here, also because of the increased risk of (expensive) rim damage on the 55.