Good talking with you Saturday at Hendrick. Hope you are enjoying your new shoes. I looked, and they are the same ones they put on "Sam". They ride good and seem to be pretty sticky in the rain (Toyo Proxes4).

One thing you may want to check is the tire pressure. When I got "Sam" home last week, the first thing I always check is the pressure when I get a new car. I know the dealership wants to sell a "soft, smooth" ride, so they have a habit of lowering the pressure. I found they had 30psi in all four when the door jam calls for 38psi.

Either that, or their tire pressure gauges "blow".






Say it slowly.





Tire pressure..........gauges..........blow.






(I know, bad joke... sorry...)


Bob

 

I've noticed that when the car is delivered, pressure is a bit low too. Pressure in the 17" Pirelli's that came with my 05 MCS were at 34, where spec is 38lbs.

One theory could be that the dealership lowers the pressure for a softer, cushier ride.

Another theory is that the VPC sets the pressure a little low since the car could be destined to any altitude from Denver to below sea level (if this makes a difference??? just a theory).

Regardless, the advise is good: Check the tire pressure even if the car is brand new. Also, buy a decent tire pressure gauge (throw away the 'stick' type that cost .99 cents at the grocery store). I measured a 2lb difference in the stick type vs a good dial gauge. Check tire pressure at least once a month.

Lastly, when rotating (if you rotate), changing, or adjusting inflation of tires on a MINI, it's important to reset the Flat Tire Monitor. The only way the flat tire monitor system can work is by allowing it to establish a baseline that is used to compare against.

Taken from Introduction to MINI BMW Training Manual:

Procedure: Switch on ignition and then press and hold the flat tire monitor button for longer than 4 seconds. The control unit will then go into learn mode (initialization). The system then enters a learning phase. Due to the preset threshold values, this phase can last anywhere from 45 minutes to several hours depending on the driving style and the number of data rejections. The system is ready to provide warnings after a minimum of approximately 10 minutes.

The system must be initializied if:
The tire pressures are adjusted (must be set cold)
The tire positions are altered
Tires are changed

For anyone who cares for even more info from the factory training material:

Tire Pressure Warning System (RDW) is a system which alerts the driver to changes in tire air pressure by monitoring the rotational speed of the tires. RDW interfaces with the ABS/DSC system to receive wheel speed information. Only rotational speed is monitored, not tire pressure.

The purpose of the RDW systm is to warn drivers of potentially hazardous conditions caused by tire loss of air. Underinflation is a tire's #1 enemy. It results in unnecessary tire stress, irregular wear, loss of control, and accidents. A tire can lose up to half of its air pressure and not appear to be flat.

Under inflated tires are major causes for blowouts. An under inflated tire runs hot due to the action of the tire as it rolls under the car. The sidewalls become squashed outward, and it is this movement that causes the tire to generate heat and fail.

The RDW system is not a substitute for regular checks of tire air pressure, but rather a warning system for loss of air conditions that arise while driving. The driver is responsible for ensuring that the tire pressure is set correctly. The system can not perform a plausibility check on whether the tire pressure set is correct. It can only monitor pressure set as the movement of initialization is compared with the warning values stored in the control unit.

 

Read the entire jamb label and read it carefully!

The sticker on my car (an '03 MCS) calls for various tire pressures, based on the tire size and the load the vehicle is carrying. The 38 psi spec is for 205/45 R17 (the MCS stock 17" size), 195/55 R16 M+S and 205/45 R17 M+S, but only when the car is fully loaded -- four adults and luggage. How many of you ride four-up, with luggage? In your MINI???

The 33 psi figure is what is specified for those same tire sizes when carrying only two people. I'd say the dealership made a reasonable assumption there. I can guarantee that the ride is better at 33 than 38 psi.

By the way, 30psi is what is recommended for 195/55 R16 tires in both the Cooper and the Cooper S, as well as 205/45 R17 in the Cooper.

There are lots of reasons to deviate from the recommended pressures and I'm not going to propose discussing them here. But I'd not say the dealership was wrong at 34 psi in your car, Tarzan, and might be correct for Rev Limiter's tires -- I don't know what car you drive.

 

LJinNC brings up a very good point. My 2005 MCS does not have a table of varying size/pressures on the door jam as his 2003 apparently does. It specifies 38Lbs Cold as maximum tire pressure. The sidewall on my Pirelli EuFori@ 17X45X17 Performance run-flats indicate a maximum tire pressure of 50lbs and max load of 500kg (about 1100lbs).
My label does however, say refer to the Owner's Manual. The Owner's Manual says: Refer to the door jam for original tires. On the next page is a table for non-original tire fitting pressures, which I am assuming is the same table that is on LJinNC's door jam.

The table (page 98, 05 handbook) specifies 33lbs with MAXIMUM loading of two adults. 38lbs is recommended for four plus luggage.

Why is the pressure recommended higher with more occupants and weight, and lower with fewer occupants? Because if all you every carry is an occasional passenger, you will enjoy a softer ride with the lower pressure. If you jam more people and gear into the car, the tire pressure needs to be higher so as to keep the sidewall squish to a minimum and preserve the safety of the car. A bit of ride quality will have to be sacrificed.

So, unless you are proned to add 4 or 5 pounds of air pressure on every occasion when you carry more than one human passenger, the lesser of two evils could prudently be to opt for higher air pressure within the range, and deal with the stiffer ride quality when riding solo, versus driving on under-inflated tires when carrying more people and stuff.

Perhaps the smartest idea would be to set the air pressure half-way between the two, say: 36lbs in my case.

Anyway, it's all a matter of digression from my original intent, which was to recommend that tire pressure be checked regularly using a good quality gauge, and reset the run-flat indicator each time.

 

Hmmm........


Maybe I was assuming too much. Apparently both of you are right. (?)

When I got my new '05 MCSC, Hendrick MINI had put some aftermarket wheels on it with Toyo Proxes4 size 205/45 ZR 17 rated at 88W M+S, and that size is not covered in the owner's manual (at least for an '05). The door sticker for my '05 says 38psi. The door sticker for my '02 MCS was 33psi. I assumed that these are the same Proxes Hendrick put on George's MCS because I compared the tread pattern with mine - NOT the size.

My bad.

Right now I don't know what psi I should be running.

Which shows 'ole Bob can show his butt with the best of 'em. :smile: (Years of practice..)

 

Sorry to hear that MINI is cutting corners by eliminating the helpful tire pressure chart on the door jamb. Read the manual, either way (the information I used came from the manual, by the way).

Though I've never had more than one adult and two kids -- or two adults -- in my car at once, I do recall having seen mininc's car with four people in it; two adults and two kids. I don't recall having seen any luggage on that occasion, so don't know if he needed the full 38 psi. Mostly, MINIs carry one or two people at a time; there isn't room for two of anything other than kids in the back. To be truly prudent, maybe the thing to do is to inflate the tires to suit the one- or two-passenger load, then drive your SUV when carrying a heavier load.

Running at the higher tire pressure isn't necessarily the lesser of two evils. The jarring isn't only harder on the occupants, but the vehicle,too. And overinflation can cause premature wear on the center section of the tire.

That's all digression: My point was that the dealership made some prudent estimates of the average conditions under which the car would operate, so don't knock them for that. But you're right on your original point: Check the tire pressure regularly. Tires can -- and will -- lose air over time. And, of course, check your tire pressure with your Official MINI Digital Tire Gauge!

 

The new tires are nice, they are Toyo Proxes4 size 205/45/17.

I checked my tire pressure the next morning and they were all set on 37 psi. I ran my last set on 36 psi and they seemed to do OK.

I still had some tread left and had about 28,000 miles on my 205/45/17 Dunlop non run flats. The car felt real loose in the rain on the highway last Monday, so I decided to get new tires.

 

Last car I had picked up a nail one morning. I asked the mechanic at the tire store after he patched it how much air he put in. He said 50psi. I asked him why he put so much air in it and he said "That is what is printed on the side of the tire".

Okay...

They didn't charge me anything to patch the tire. And the service I got was worth every penny of what I paid.