[QUOTE]Originally posted by maxnix "]And the reason for not matching the pressure of the other three tires is ... ?

Well, I dunno ! LOL!

Actually, I've seen the numbers fluctuate a LOT lately with the changes in temperatures up here in NJ .. last week it was like 80, 2 weeks ago it was in the 50's .. strange weather goin on.

They never ALL match perfectly .. some are always off by 1-3 ... but the right rear passenger is always the 'oddball' ... it kind of makes him ... 'unique' ! But, I'll add a little air eventually !

Three psi tire to tire is a lot of variance. Even I can usually discern that. I wonder if it is the method of measurement? Random variances when cold should not occur.

Brian, I think that dezm45 must be using the on-board tire pressure monitor system. This might be acting up or simply does not have the resolution of a good external tire pressure gauge, perhaps. This is, of course, a WAG.

My tires are always within 0.5 psi of each other (assuming of course, no leaks, etc.). Goes up and down certainly with weather changes a small amount. I measure every week, and the change tends to be less than 1 psi week to week drop if the weather has been relatively constant (typical SF Bay Area ). If they drop by more than 1 psi from where I want them, I always pump them back up (cold, of course!) and set them to the correct value.

IMO, correct tire pressure maintenance is fundamental to achieving good handling when pushing the car, and decent wear (tires and suspension), etc.

Z

That's why I am wondering how accurate this monitoring system is. Doesn't it count axle rotations and interpolate?__________________Brian1995 Q45 & Q45t & 2000 Q45

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I am from also from new Jersey and when we got a cold front that came through two weeks ago i received a warning that i had a flat tire. I stopped and pulled over in a gas station but there was not a problem whatsoever. the warning would not go out until I put in a few lbs. of air in all the tires. I would hate to get that warning while on the N.J. turnpike doing 75 and then stop for nothing.

SIDVICIOUS wrote:I am from also from new Jersey and when we got a cold front that came through two weeks ago i received a warning that i had a flat tire. I stopped and pulled over in a gas station but there was not a problem whatsoever. the warning would not go out until I put in a few lbs. of air in all the tires. I would hate to get that warning while on the N.J. turnpike doing 75 and then stop for nothing.

At 75 on the turnpike is precisely when you want that warning. And you wouldn't be stopping for nothing, you would be stopping to add needed air into your tires. Without doing so, you could easily damage your tires from running at highway speeds with underinflated tires.

The reason you experienced the warning recently, is because the colder weather had the effect of lowering the cold air psi in your tires. They needed more air to bring them up to spec and the warning system did its job by telling you so. I got the same warning early one morning after owing my M45 for only a couple of days. When you added a few lbs. of air pressure, you solved the problem and the warning went away. I solved the problem the same way. In both cases, the system worked exactly as it was designed.

Tire pressure is one of the most neglected items of routine car maintenance, and a common reason for tire failure is underinflation. The results can be very dangerous. Remember the recent Firestone/Ford debacle? Most of those failures were due to underinflated tires in loaded SUV's on hot summer pavement in the south and southwest. Most of those failures would have been avoided with proper tire inflation, taking into account the load in the vehicle. It is only a short matter of time before automatic tire pressure monitors will be standard equipment on just about every vehicle made, all because most people are habitually lazy (or ignorant of the importance) about checking their tire pressure.

It's an interesting fallout resulting from the demise of the full-service gas station. I'm old enough to remember filling up at those old stations and having at least one or as many as three attendants checking tire pressure, oil level, battery level, hose, belt and wiper condition, coolant level, etc., while filling the tank (not to mention cleaning the windshield). Not only was it a true service to the customer, it's often how they generated sales (legitimate and otherwise) for their repair bays.

Russ

russg wrote:It is only a short matter of time before automatic tire pressure monitors will be standard equipment on just about every vehicle made, all because most people are habitually lazy (or ignorant of the importance) about checking their tire pressure.

The US Federal government is considering (may already have done it) mandating tire pressure warning systems on vehicles. It is unfortunate that we have to have laws to protect us from idiots! :rolleyes If it weren't for the fact that accidents tend to take out innocents too, I would say let natural evolution take its course!

Z

russg....I know your point and did just that but I did not receive a warning that the tire pressure was low the warning was that I had a flat. has anyone gotten that warning or is it me? If you knew how dangerous the N.J. turnpike is you could understand my reasoning. Speaking of tires/rims has anyone noticed that the rims stick out slightly further than the tires? So if you screwup parking it will hit the rims not the tires?

SIDVICIOUS wrote:russg....I know your point and did just that but I did not receive a warning that the tire pressure was low the warning was that I had a flat. has anyone gotten that warning or is it me? If you knew how dangerous the N.J. turnpike is you could understand my reasoning. Speaking of tires/rims has anyone noticed that the rims stick out slightly further than the tires? So if you screwup parking it will hit the rims not the tires?

My warning said "flat tire" as well, and all tires were far from flat. But hey, it got my attention, and obviously yours as well. I assume that the system is designed only to detect pressure below a set threshold. In other words, it probably can't differentiate between being 3 lbs. under minimum spec or 30 pounds under minimum spec. Furthermore, it doesn't know if the pressure drop happened over three days or three minutes. Therefore, the message takes the more extreme approach. At least that's my take on it. Personally, I like having the system, and would want it on any future cars I own.

Russ

Hey guys ... just curious -- what are you keeping your tires inflated to ? Sid, since you're in NJ as well, what are your tires at ? I'm keeping mine at 34 psi - COLD ...

On a similar note regarding WARNING systems - I was pulling a 'Kramer' the other night while driving on the AC Expressway ... My gas light had come on, but I still had '38 miles to empty', but I knew a gas station was coming up soon. I knew there still had to be a good 2-3 gallons left. Well, I had only gone about 4-5 miles, and up on the VIS a got a LOW FUEL warning, and it would NOT go off -- it basically rendered every other option useless on the VIS -- and the distance to empty was simply at '---' after being at 38 miles -- very strange .. when I did stop to fill up (less than 3 miles later) the car clearly only took 18 gallons of gas ... has anyone else had this happen - it is a good thing, though - that it comes up so soon -- but, how much further can ya REALLY go, before truly running out of gas ??? No, I wasn't going to try it !!!

"___" DEZM45 it also happened to me. It first showed low fuel but I have the navagation system and it gave me the option to plot directions to the nearest gas station. Since I knew where I was and believed I had enough to get where I wanted I closed out the navagation option and went back to the fuel info. It only showed the "__" miles left but everything else on the display worked, I.E. audio, climate control etc. For a "muscle car with brains" you would think that it could at least tell you down to a few miles. I would also love to find someone who could tell me how to bypass the idiot message that you have to agree to every time you start the car for the navagation system.

Yeah Sid .. I failed to mention that -- at first, I couldn't do everything, but then some of the items were functioning - until it popped up again.

I don't have the Navi, but I do remember reading somewhere about someone figuring out a way to bypass that 'idiot message' !!! Now, if I can only remember WHERE I saw it !

Sid it will warn you as soon as any tire hits 27 psi. We had a cold front blow through El Paso (believe it or not) and it did the same to me. I'd hope there was a reset button but you have to add air.

03 Silver W/Black leather Loaded.

potatohead wrote:03 Silver W/Black leather Loaded.

Cool! Welcome to the 2003 M45 club! You have exactly the same exterior and interior colors as mine, although mine is not loaded.

Please also add to the poll zerothread?id=145379 if you have not done so! Thanks!

Z

04 M45black on black with the dark wood.+nav

(trying to sell it)

06 M45 Sport crimson roulette/stone leather Journey/Technology Pkg Aero kit

I leased an 06 M45 Sport (Black/graphite, technology pkg, MES pkg, aero pkg) a little over a week ago (2/17). So far, I'm thrilled to death with the car although I really haven't been able to drive it all that hard due because I'm still in the break-in period. From what I can gather so far, it's fast enough and handles well enough for a street car, at least for the crowded and congested roads around where I live...

Best regards, Matt

p.s.) Here's a quick pic...

M.45ACP wrote:I leased an 06 M45 Sport (Black/graphite, technology pkg, MES pkg, aero pkg) a little over a week ago (2/17). So far, I'm thrilled to death with the car although I really haven't been able to drive it all that hard due because I'm still in the break-in period. From what I can gather so far, it's fast enough and handles well enough for a street car, at least for the crowded and congested roads around where I live...

Best regards, Matt

p.s.) Here's a quick pic...

Very nice! I like the black color!

Note that I actually recommend driving it very hard occasionally during the initial break-in period. You need the pistons and rings to settle well, else there will always be a bit more blow-by than you want. Change oil and filter very, very soon and often during this period!!!

There have been informal studies that show that accelerating the pistons a bit harder than normal (not continuous high rpm, but high acceleration rates) is good. To make the pistons, and thus the rings, "reach" a teensy amount higher than normal in the cylinder walls. Apparently, (and I am NOT an expert,) this makes the rings score the cylinders higher up the walls and sets them better.

Take this info for what it is worth. All I can say, in my case, given the very low oil consumption I have given other 2003 era M45's, it seems to have worked!

Z

[URL]

szhosain[/URL wrote:]

Very nice! I like the black color!

Note that I actually recommend driving it very hard occasionally during the initial break-in period. You need the pistons and rings to settle well, else there will always be a bit more blow-by than you want. Change oil and filter very, very soon and often during this period!!!

There have been informal studies that show that accelerating the pistons a bit harder than normal (not continuous high rpm, but high acceleration rates) is good. To make the pistons, and thus the rings, "reach" a teensy amount higher than normal in the cylinder walls. Apparently, (and I am NOT an expert,) this makes the rings score the cylinders higher up the walls and sets them better.

Take this info for what it is worth. All I can say, in my case, given the very low oil consumption I have given other 2003 era M45's, it seems to have worked!

Z

Thanks for the compliment! I'd sworn that I would never own another black car as it's sooo hard to keep clean, but I think it looks great when it IS clean, and besides that, it was in stock!

Interesting point about the break-in. Lord knows that must be one of the most highly debated issues regarding cars. I've done quite a bit of reading about engine break-in, and "Motoman" has a pretty good article about the "hard break-in philosophy"...

http://www.mototuneusa.com/break_in_secrets.htm

As convincing as his argument is*, the best way to break-in an engine still seems to be under debate. I've read some articles that contradict the "hard break-in" theory, and there was a recent article in Road & Track (At least I think it was R&T) that mentioned Motoman's article, but they disputed his claims. It's my understanding that most manufacturers run each engine on a dyno to ensure that there are no leaks or other problems, and I understand that some manufacturers (Such as AMG and BMW's "M") run the engines hard to both seal the rings properly and to verify it's power output.

I suspect that the ideal break-in is somewhere in between. I believe that it's not beneficial to baby the engine, nor is it ideal to run it super hard either. I've always taken something of a middle road in regards to break-in. Basically I "cycle" the engine through various rev ranges, starting at a relatively low rpm, and then progressing to higher and higher rpm as the miles accumulate (Reaching max rpm within 500 miles**). One of the important steps imho is to allow the engine to coast down from high rpm (i.e., run it up to say, 5000 rpm in second gear, and back off the throttle w/out upshifting). This builds up crankcase pressure which helps to expand the lower piston rings (Oil control rings) so that they set against the cylinder walls. I've owned more than a few high performance cars and motorcycles, and I've always broken in each car/bike the same way. Each car or bike has never burned a drop of oil and always produced excellent dyno numbers compared to other stock examples (Albeit I did not dyno all of them). So I think the whole break-in process is still under debate!

* One thing that I disagree with is his reasoning behind why the manufacturers reccomend their break-in period. Sounds pretty thin imho...

** At which point I have the oil changed.

Best regards, Matt