[Finerthings]

Best to check your COLD pressure 1x/month manually & know what it s/b, based on ambient temperature. (I know few will do this)

Suppose it is 68 & car sitting overnight & you check & CTP = 30F, 33R & you have it part load. You must add 3# to each tire & you need not reset your TPMS.

This is what makes sense to me too, although I might not be as religious to check my Mercedes every month like you, although that sounds like best practice. Most don't realize how important tire pressure is... I know I drive my husband crazy. When I get my Macan S in April I will try to remember monthly, but no promises!

 

[adlim]

anyone of you guys experience problems with your tpms?


this happens to me regularly. air on my tires are ok. tpms signals i need to put air on it. then i reset the system then it'll be fine for the rest of the trip up until i shut down the engine then it'll give a sign that i need to add air again. then i reset it again then it goes over and over..


any one experience this?

 

[Jellybean]

TPMS sensors in the Macans (and all newer Porsche models) measure air temperature and compensate accordingly. May be the reason some are seeing a different pressure displayed between the main and fill screens. That or they're just aren't resetting the system after adding air. Any pressure adjustments should be followed by resetting the system. Any reference to pressure specs are always cold inflation specs.

Is this statement true? The sensors taking in account the air temperature and measuring tires pressure accordingly?

The TPMS system on my GTS is going to drive me nuts if my issues continue. My beloved is 6 miles away from turning 5,000 miles. About 6 weeks ago i saw a warning light from the front left, then a few days later the front right, and back left. I would get one light cleared and a couple days later a new light would come on. When the first warning light came on I took it to a tire store and had them check the tires and he added air to the one tire in question. I asked the guy why the tire was reading low. Our temps haven’t been cold, but the guy told me that oh it was reading low because of the change in temperature. Two other warning lights came on at different times, then with driving would go away. After sharing what was going on with the car and the tires to the guy who details my cars, he ran it to the dealer for me while I was at school. They put it up on the rack and checked the tires added air to all four and reset the system for him.

Two weeks ago I got a warning light again and I was running errands all morning and afternoon. When I was at my last stop the light came on. So I zipped to the dealer and tried to explain that they just saw the car a month ago for this same problem and the service advisor guy in the bay treated me like I had no clue what I was saying and pretty much dismissed me and told me that it was nothing and put air in all four tires again and told me to enjoy my GTS. When I was getting into the car, I asked why the light came on again and he said the temperature was cooler in the morning. I tried to tell him that the light didn’t come on first thing this morning, it came on after driving the car for hours running errands. He closed the door and said it was the temperature that made the light come on and told me to have a nice day. Is it normal to have to add air to all four tires about a month later? I really don’t drive much on the highway, I drive pretty much all city driving.

My friend who is a guy they put the car up on the rack and check all tires, add air and reset the system. For a female I got a condescending attitude and sent on my way with at least air added to the tires. Why oh why are males treated differently than females when it comes to cars?

Sunday I was running errands all day, stopped at school and worked in the building for a few hours and guess what, the stupid light is back on the same tire. We had beautiful weather that day. Again the light came on when I pulled up to park at home. I could see blaming the weather if the light was on first thing, but to come on after driving around half the day?

I know i need to take her back to the dealer and get this checked out, but to be honest I haven’t had the best interactions with this dealer so far. They treated me so well (NOT) when I was looking at the Macan last October, that I ordered the car from a dealer in FL this is a story for another day. I have stopped at this dealer a few other times and have not had good experiences either. I am one of those weird ones who does like to take the car to the dealer to have work done on it, but part of me can’t bring myself to go back to them. In our city we have one Porsche dealer, so they have the market. The nearest dealers are about 2 hours away. The S5 is going in to the Audi dealer on Friday for her annual oil change and check up and part of me wants to beg the Audi dealer to check out the Macans tires for me. My Audi dealer has already told me no that they won’t do routine service on it. I have been using this Audi dealer since July 2010 so I do trust them, and their advice. They haven’t lead me wrong yet.

Thanks for reading my mini novel.

 

[wspollack]

@Jellybean: Set It Yourself

@Jellybean:

The first thing I would do is check and set the tire pressures yourself.

1) Buy an accurate gauge,

I have some experience buying and using these gauges over the years, because I'm fairly persnickety regarding pressures in my motorcycle tires. When I wrote a review of a motorcycle TPMS add-on system four years ago for webBikeWorld, I took a picture of some my gauges then:

I had been migrating, over the years, from dial gauges to digital ones.

I recommend you buy one of these (and since you have a Macan, and I recall reading that you get it detailed, etc., I imagine you can afford to splurge a little here, in the interests of accuracy):

A) K Tool's KTI 89001: KTI89001 | Air Compressors | Shop Tools and Equipment | Product Categories | Tools | K Tool International Site

In our range of pressures, this is accurate to within c. 0.9 PSI. I've owned this for three or four years, and is my "go to" gauge when I'm at home, in the garage. (It has an inlet for a large air compressor line, which you probably won't be using, but in any case it's a nice gauge, with a user-friendly chuck for checking pressure.)

You can get it via Amazon: www.amazon.com/K-Tool-International-KTI-89001-Digital-Inflator/dp/B00CG674GY/

B) Motion Pro 08-0684: https://www.motionpro.com/product/08-0684

Motion Pro sells quality tools (mostly motorcycle oriented), and this should be no exception. It is a little more expensive, and a tiny bit more accurate at 0.6 PSI. It dispenses with an air inlet, i.e., it is for measuring only.

It's also available via Amazon: www.amazon.com/Motion-Pro-Digital-Pressure-Batteries/dp/B07GCS9ZCM/

2) Use a plug-in, i.e., 12V air pump.

If you don't have a plug-in cigarette-lighter-socket pump (or if the Macan didn't come with one -- I think some of them do, for some models or in some countries, etc.), go buy one for $20 or $30. Most auto-parts stores have these, or I see that Charleston has a Harbor Freight store (which has a bunch), etc.

You won't need a super high quality pump, because you won't be using it much.

3) Check and adjust the pressures some morning.

Before you drive anywhere, e.g., in the morning, after the car's been sitting around, check the pressures with your new gauge.

And adjust them, if necessary, with your pump ... but using the good gauge, e.g., mostly ignoring any built-in gauge in the pump. If the pump does have a gauge, you can pump them a few PSI higher than desired, and then use the good gauge's bleeder button to let some air out, so you wind up with the desired pressures. If you're not familiar with the "clip-on" outlets attached to most 12V pumps, have someone show you how they work, i.e., push straight on, and solidly so, and then move the clip in place to hold it on. Similarly, if you don't understand how to use the bleeder function on one of those gauges, enlist some help and instruction from a DIY type of friend.

And speaking of desired pressures, let's set the pressures based on, say, 35 degrees F (since I gather that would be about the coldest it gets in Charleston for the next few months, right?). When it's warmer, your pressures will be a bit -- but not ridiculously -- higher than our target, and that's acceptable.

Our target pressure, for that lowest temp, will be 33.0 front and 36.0 rear.

Let's see, using this spreadsheet I constructed for this work a while back in LibreOffice Calc ...

If you're doing this work on a 70-degree morning, you'd set those F/R pressures to be 36.4/39.6.
If you're doing this work on a 60-degree morning, you'd set those F/R pressures to be 35.4/38.6.
If you're doing this work on a 50-degree morning, you'd set those F/R pressures to be 34.4/37.5.
If you're doing this work on a 60-degree morning, you'd set those F/R pressures to be 33.5/36.6.

That sort of thing.

This works backwards, too. So, if the temp over the next few months happens to get up to 70, your tires will be 3 or 4 PSI over-inflated, which, as I mentioned, is no big deal for typical cars used in typical ways.

Now, because of the amount of air in those big tires (as opposed to, say, motorcycle tires), you should be good to go for several months. That is, unless something is actually physically wrong, e.g., you hit a massive pothole, or smashed a rim into a curb, or picked up a roofing nail, etc.

4) Make sure the Macan is set for a normal load.

You want to make sure that Full Load is NOT checked on the car's setup. (I'm guessing that you don't generally drive the car with three passengers and other stuff to be hauled around, or pulling a trailer.) Check out Page 173 | 2017-2018 Macan Manual | Porsche iManuals and the next few pages to read about this, if you're not familiar with this setting.

Note that when you have the right-thumbwheel turned so that you see the pressure for the four tires you will not see the pressures until you've driven for a few miles. And it may take another mile or two after the display starts showing numbers for the numbers to sort of stabilize (I think there's some averaging going on in the sensors, but I'm not sure). Of course, if you drive for an hour, and especially aggressively, the shown pressures should go up a few PSI, as the tires flex and the air inside heats up (per Gay-Lussac's law, as you'll recall from high school physics or chemistry) -- this is much more dramatic with motorcycle tires, as the increase during a ride may be 15 PSI or more.

Hope this helps get you started. After this, if there still seems to be a problem, take it to the dealer. But my overall suggestion here is to set things up in a controlled manner beforehand -- not after driving around -- using a good gauge on cold tires.

 

[CarGuy07]

Curious what PSI you guys are running in the winter on the 20” tires?

 

[CarGuy07]

@wspollack - are those numbers backward? Why would you lower the TP when it’s colder?

 

[wspollack]

@wspollack - are those numbers backward? Why would you lower the TP when it’s colder?

Nope, they appear correct to me. But perhaps I didn't explain the situation clearly.

I assume that your talking about this part of my post:

If you're doing this work on a 70-degree morning, you'd set those F/R pressures to be 36.4/39.6.
If you're doing this work on a 60-degree morning, you'd set those F/R pressures to be 35.4/38.6.
If you're doing this work on a 50-degree morning, you'd set those F/R pressures to be 34.4/37.5.
If you're doing this work on a 60-degree morning, you'd set those F/R pressures to be 33.5/36.6.

And here's perhaps a clearer explanation. Recall that our target was to have the cold tire pressure be 33/36 F/R at 35F outside temp.

If you're setting the cold tire pressure when it's warmer outside than your target temp, but your goal is to have the target pressure at the target temp, then you have to pump up the tires greater than the pressures desired at the target temp. That's because as the ambient temp drops -- it's, say, 60F this morning, when you're doing your pumping and measuring, but in two months it will be, say, 40F -- so will the pressure inside the tires also drop.

Put another way, if your target is 33/36 F/R at 35F outside temp, and you're checking and optionally adjusting your cold-tire pressure, and it's actually 35F outside when you're doing this work, then you'd set the pressures at your target, i.e., 33/36 F/R. That makes sense, right? Well, the next morning it's a heat wave outside, and those internal gauge pressures of air in your tires would be higher (because the air in the tires is also warmer); for instance, if it were 70 the next morning, and you put a gauge on the tires (having adjusted them the day before, when it was 35F), you should get a reading of 36.4/39.6, instead of 33/36. What I have posted is just the reverse: it's, for example, 70 outside, but you want to have your tires at the correct pressure (33/36) when the ambient temp is the coldest it will be for the next couple of months.

But the closer it is to the low-expected temp (35F in our example) when you're doing the actual checking and adjusting, the closer you will be to setting the tires at the pressures (33/36) desired at that low-expected temp.

Does that help?

 

[wspollack]

@wspollack - are those numbers backward? Why would you lower the TP when it’s colder?

I just went out for a local errand, and I took a photo (before I had gone very far -- tires still cold -- at the first red light) for a graphical representation of the explanation:

So, you see that at 37F the pressures are 35/38.

I typically set the pressures for the winter months with a target of around 20F. Thus, when it's 20F out, today's 37F readings of 35/38 drop down to c. 33/36. (So, if I were first filling the tires outside today, in the driveway, at 37F, in preparation for 20F, I would set them higher than my 33/36 20F target, i.e., I would put them about 35/38.)

Tomorrow morning, when it's supposed to be 8F, the pressures will read about one PSI lower than my desired (20F) pressures, i.e., they will read c. 32/35 F/R. That's acceptable to me, and I'm sure that 1 PSI low won't trigger any alarm or adversely affect the handling, i.e., life is a compromise.

Make sense?

 

[CarGuy07]

@wspollack - are those numbers backward? Why would you lower the TP when it’s colder?

I just went out for a local errand, and I took a photo (before I had gone very far -- tires still cold -- at the first red light) for a graphical representation of the explanation:

So, you see that at 37F the pressures are 35/38.

I typically set the pressures for the winter months with a target of around 20F. Thus, when it's 20F out, today's 37F readings of 35/38 drop down to c. 33/36. (So, if I were first filling the tires outside today, in the driveway, at 37F, in preparation for 20F, I would set them higher than my 33/36 20F target, i.e., I would put them about 35/38.)

Tomorrow morning, when it's supposed to be 8F, the pressures will read about one PSI lower than my desired (20F) pressures, i.e., they will read c. 32/35 F/R. That's acceptable to me, and I'm sure that 1 PSI low won't trigger any alarm or adversely affect the handling, i.e., life is a compromise.

Make sense?

Yup, got it. Understand now that it’s the target pressure. Thank you for taking the time to explain. ?

 

[iconoclast]

I agree, being a female does not mean that you cannot learn to check your TP manually yourself. It is easy! Get a box of disposable gloves to keep your hands clean.

I set my Macan to "Part load" which is (for 19" Summer tires) 33F, 36R @ 68 degrees.

I do not rely on the TPMS to tell me the true pressure or the true +/- since it changes & not always explainable by cold vs. driving for miles or ambient temp.

Sometimes it will say I am 3# low in RF tire & 5 min later will say I'm perfect, right at "0."

I use my gauge.

I also bought a great compressor that I carry & use instead of having to find a gas station that has air. I NEVER let dealer or tire shop do my TP (unless getting new tires or repairing a leak)

Slime 20247 Digital Tire Gauge
Bought @ Walmart $8.87
Part # 2247 10.06.14
UPC Bar code: 7 16281 50717 5
Made in China
www.slime.com
Accessories marketing, Inc., a division of ITW, Inc.
125 Venture Dr., Suite 210, San Luis Obispo, CA 93401

Most of these gauges are accurate to ~ +/- 1#.
Just be consistent, use the same gauge & same person (you) to check/fill all 4 tires.

I like to go over by 0.5-1# & then release a bit to get it exact.

I recommend:
Viair 78P Compressor
It is relatively quiet.
Fast
Has a case
was $41 on Amazon when I purchase in 2017.
[ame]https://www.amazon.com/Viair-78P-VIAIR-Portable-Compressor/dp/B01N224N1U/ref=sr_1_2?ie=UTF8&qid=1500701219&sr=8-2&keywords=VIAIR+77P+PORTABLE+COMPRESSOR[/ame]

Most people do not put the correct pressure in their tires. A common error is to use the MAX pressure on the tire sidewall. (Don't) Use the pressure in the owner manual.
Virtually no one seems to know that the recommended pressure is for 68˚F ambient temperature & you need to adjust your target pressure.

(No, the gas station guy does not know this!)

Read about temperature adjustments:
https://www.macanforum.com/forum/wh...m/wheels-tires-suspension/165522-tire-pressure-tpms-inaccuracy.html#post2451332

Also read:
http://www.tirerack.com/tires/tirete....jsp?techid=73

 

[wspollack]

...

Also read:
http://www.tirerack.com/tires/tirete....jsp?techid=73

I think you must have edited your post, or done some other manipulation of the URL (which doesn't work, because those ellipsis dots shouldn't be part of the actual URL). I believe the TireRack link you meant to post is this: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=73

 

[iconoclast]

I think you must have edited your post, or done some other manipulation of the URL (which doesn't work, because those ellipsis dots shouldn't be part of the actual URL). I believe the TireRack link you meant to post is this: https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=73

Yes that is the link & your post also added the dots. Must be the forum software?
When I C/P the link there were no dots substituted by me.

I'll try again:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=73

Nope
Forum substitutes the dots

Article title is :
TIRE TECH: AIR PRESSURE, TEMPERATURE FLUCTUATIONS
From Tirerack.com

Key point is:
"The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower)."

 

[wspollack]

Yes that is the link & your post also added the dots. Must be the forum software?
When I C/P the link there were no dots substituted by me.

I'll try again:
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=73

Nope
Forum substitutes the dots

Article title is :
TIRE TECH: AIR PRESSURE, TEMPERATURE FLUCTUATIONS
From Tirerack.com

Key point is:
"The rule of thumb is for every 10° Fahrenheit change in air temperature, tire pressures will change about 2% (up with higher temperatures and down with lower)."

Once again, I failed to explain properly. Let me try again.

If you click on the TireRack you provided in post # 32, you'll get a page-not-found error at TireRack's web site. If you click on the link I provided in post # 33 -- or the one you provided in post # 34 -- it will work.

Yes, forums will DISPLAY long links with ellipsis dots substituted for some characters, but if you HOVER over the links (mouse over them, without clicking, on a computer, or hold down your finger for a few seconds on an iPhone) most browsers will show the actual link -- i.e., without the dots -- in a corner.

That error in post # 32 is because the ACTUAL link -- not just the DISPLAYED link -- has dots in it. That will happen, for example, if someone does a cut-and-paste of a link displayed on a forum page (or some other displays), and then does a paste into a forum post.

So I figured out the intended (non-dotted) link you meant to post in # 32, and provided it in # 33. They're different links, even if they look the same in those two posts; a hover (or click) will reveal that they're actually different links.

Hopes this makes sense.

 

[Jellybean]

@wspollack thank you so much for your detailed response, I truly appreciate your time and advice to help me.

I do have a cheap gauge that lives in the glove box that will be replaced ASAP. My dad did teach me to check the tires in high school after he had to come and meet me to change many of them. He changed so many that he got my AAA coverage so I would be covered. My awful tire luck unfortunately continues to today. Dad lovingly called me a tire hit woman back in high school.

Thankfully I haven’t had to use road side assistance for any issues, keeping fingers crossed.

Again thank you for your time and links.

 

[iconoclast]

Once again, I failed to explain properly. Let me try again.

If you click on the TireRack you provided in post # 32, you'll get a page-not-found error at TireRack's web site. If you click on the link I provided in post # 33 -- or the one you provided in post # 34 -- it will work.

Yes, forums will DISPLAY long links with ellipsis dots substituted for some characters, but if you HOVER over the links (mouse over them, without clicking, on a computer, or hold down your finger for a few seconds on an iPhone) most browsers will show the actual link -- i.e., without the dots -- in a corner.

That error in post # 32 is because the ACTUAL link -- not just the DISPLAYED link -- has dots in it. That will happen, for example, if someone does a cut-and-paste of a link displayed on a forum page (or some other displays), and then does a paste into a forum post.

So I figured out the intended (non-dotted) link you meant to post in # 32, and provided it in # 33. They're different links, even if they look the same in those two posts; a hover (or click) will reveal that they're actually different links.

Hopes this makes sense.

Yes, it makes sense & I had tested & saw the your link worked, despite the "..." & mine did not. I also noticed that "..." appeared for both of us so, I focused on that aspect. Which turned out to be irrelevant.

Yes, I did do a cut & paste of my previous forum post to save time & that is likely why the link failed to work.

Thanks for the explanation.

 

[Jellybean]

Well I am not losing my mind. I took my S5 to the Audi dealer for her annual service and I was asking my favorite service advisor if they had time to check the GTS that day since I really didn’t want to go back the the Porsche dealer about the tire. So I run the GTS to Audi and Jim found the nail with just a quick look. He filled up the tires for me, marked where the nail was and sent me on my way.

So I’m hanging out at the dealer now hoping that it can be repaired since the nail is dead center of the tire, or the world will go on if I have to buy a new tire. I had the same service advisor help me today as the guy who just poo pooed me 2 weeks ago and couldn’t be bothered to listen to me. Didn’t recognize me which I thought was good, and didn’t ask who marked the tire where the nail was.

So my awful luck with tires continues

 

[wspollack]

Well I am not losing my mind. I took my S5 to the Audi dealer for her annual service and I was asking my favorite service advisor if they had time to check the GTS that day since I really didn’t want to go back the the Porsche dealer about the tire. So I run the GTS to Audi and Jim found the nail with just a quick look. He filled up the tires for me, marked where the nail was and sent me on my way.

So I’m hanging out at the dealer now hoping that it can be repaired since the nail is dead center of the tire, or the world will go on if I have to buy a new tire. I had the same service advisor help me today as the guy who just poo pooed me 2 weeks ago and couldn’t be bothered to listen to me. Didn’t recognize me which I thought was good, and didn’t ask who marked the tire where the nail was.

So my awful luck with tires continues

Hah: "That is, unless something is actually physically wrong, e.g., you hit a massive pothole, or smashed a rim into a curb, or picked up a roofing nail, etc." (post #26 ).

Good to know that you're not losing your mind! Maybe the same can't be said of the SA who didn't recognize you; well, he may not have lost his mind, but he's certainly not very observant.

I still recommend that you buy one of those two gauges -- ah, spring for the Motion Pro one, life's short -- so you can see what's going on, really set your tires accurately, etc.


Happy trails.

 

[Masscan]

So I’m hanging out at the dealer now hoping that it can be repaired since the nail is dead center of the tire, or the world will go on if I have to buy a new tire. I had the same service advisor help me today as the guy who just poo pooed me 2 weeks ago and couldn’t be bothered to listen to me. Didn’t recognize me which I thought was good, and didn’t ask who marked the tire where the nail was.

So my awful luck with tires continues

My wife shares your luck with tires...:crying:

She's been thinking about trading her Jaguar XE 35t Sport in for a 2019 Mercedes GLC 43 Coupe, and she asked if she could drive my GTS this past Saturday when we go out to do our weekend choirs so she could get the feel of a good handling CUV (the only other CUV she's driven was an F-pace S). So we pull into the Burlington Mall parking lot and park in the lot on the side where Sears used to be. After lunch and a small buying spree at Macy's and Nordstrom, we walk out to the Macan ready for her to perform some spirited driving on rt. 95...no such luck. Immediately after she started the vehicle, the TPMS warning came on and reported only 20 psig in the drivers rear tire. After having her roll slowly forward, I verify that indeed something is sticking out of the inside edge of the tire that just contacts the road.

Lucky for us there is a Porsche dealership like 3 minutes from the Burlington Mall, so we drive on down. Porsche of Burlington takes me in right away, but says they don't have the tire in stock (which I find odd since the Macan is the number one seller for Porsche) and no loaner, so they install the donut spare for me, and tell me to come back on Monday when the tire comes in. Monday rolls around, I stop by after work and they put my original wheel & new tire on, and they deflate the donut spare and put in back where it belongs. Believe it or not, that is a small piece of plastic a little larger than a quarter...I now call it my $400 piece of plastic...

 

[iconoclast]

Why are people going to the Porsche dealer for tires?

Are there no Discount Tire shops or equivalent in your area?

DT will sell you a road hazard tire warranty even if you did not buy the tire there (For new cars)
I did this a couple days after taking delivery of my Macan & plan to do the same for my 911.

Yes, it will not cover damage to wheels. I can use the thousands in savings from not buying Porsche W&T insurance, to pay for wheel repair if I ever scrape a curb. How likely is it that a wheel will be completely ruined & require replacement ...that is NOT the result of a crash that regular insurance covers anyway?

To those members who just paid Porsche for new tires, just for fun, check Tirerack.com & Discount Tire & other tire shops for the price of the same exact tire that you just purchased. Who knows, maybe it is the same or less but, I doubt it.

 

[Jellybean]

@Masscan I feel for your wife! What awful luck driving over and picking up that hunk of plastic.

Luckily the dealer was close and was able to get you all fixed and on the road with a mini hiccup. It does seem strange that they didn’t have tires in stock.

I was very surprised today that my dealer got me in and out within an hour since when I pulled in the service bay was 6 cars deep, but they were all Infinity’s. Right now until the new building is built, Porsche is sharing room with the infinity dealer. Color me surprised that they didn’t charge me to repair the tire. I even offered to pay them two different times for the repair since I didn’t have any kind of tire insurance. Maybe the service advisor did remember me and felt bad he sent me on my way without listening the first time I was there. There is not many carmine red GTS’s in my city especially one with a sea turtle trailer hitch cover.