Tyre Pressure check

Evening All, How often do you check the tyre pressure on your Porsche ? I checked mine for the first time in 6 months today and the front tyres were down to 26PSI and my back ones said 29PSI. Considering the front ones are supposed to be 32PSI and the rear ones 36PSI thats a big difference. I might start checking them monthly. What do you do? It’s also worth noting that I don’t have TPMS on 987.

I have checked my TPMS to my tire gauge numerous times, and each time they match up. That being said, I check the TPMS values every time I drive.

I check tire pressure constantly by keeping it visible in the display full time. It's really the only display item that is worthwhile and something you can do something about if it's wrong. The other items like radio station, or mpg averages, or gas tank distance remaining, etc., are nice to know but unimportant by comparison.

Check every time before I drive. One click up to confirm.

Seems like all the responses ignore that he doesn't have TPMS . I believe some models did not come factory equipped. Zeus, I'd say at a minimum you should check seasonally. I find my tires always need a few lbs when it gets cold. Then check again in spring and summer when it gets warmer. However, there is a fairly cheap way to add a stand-alone TPMS . I use it for my RV. You simply replace the valve caps on each wheel with small transmitters and place a receiver somewhere in the cabin. Something like this. I'm just using that for an example but there are lots of similar products. The one I have in my RV supports 6 wheels and the receiver (which is stuck on the dash) is solar charged. It was about $125 (US). It has been a big help since the inner tire on the rear duallies is not visible during a walk-around inspection, and it is difficult to access with a pressure gauge.

Oil and tire check… standard each time I drive

For a new-to-you car, it's a good idea to check pressures monthly at first (especially without TPMS ), so you can see how YOUR car is behaving. I also check oil levels every time I fill up gas. Once you get an idea of how your car behaves, you can lengthen the time between checks accoridingly. Also, don't forget, lower ambient temperatures can change pressure a lot. I generally see about 4-6 psi drop here in Connecticut (USA) when we get into the cold winter! That will also rise up in the summer...

Thank you. Your response is much appreciated along with your suggestion 👏🏻

I've got a reminder on my phone to check oil and tires first of every month across all the cars. Once you verify a car doesn't have significant consumption once a month is honestly overkill for oil, but I do it anyway. For tires monthly is a good habit because, as noted above, it lets you correct for seasonal temperature changes.

I have TPMS too but this is the first car I've owned that has had it. One of the manuals for a Honda Civic Type R I used to own said to check the tyre pressures and oil level every time you fill it up. I kept that in mind and used to check every month or more often when large temperature fluctuations occur. I.e. in UK one day it can be 3 Celsius, the next it's 12 Celsius.

When I didn't have TPMS , I used to check the pressure every time I filled up.

I guess that would be dependent on how many miles your car is driven. In my case (garage queen) that would be a 4-6 times a year. I mostly drive short trips so it couple be months between fill-ups.

There is a general rule of thumb that tires that have no leaks or other issues will naturally lose about 1 PSI of pressure per month. Also for every 10°F +/- of ambient temperature change equates to roughly 1 PSI tire pressure change. These are rough guidelines. What that means to me is that at a minimum , I check/adjust pressures, with a quality manual gauge, once a month or anytime we have a significant change in the weather. The original TPMS modules that came with my Cayman were very accurate. The replacements have been less so, but still give me a good idea of any issues. I generally keep the tire pressures displayed as I drive. It's good to have an early warning of an issue, before it turns into a problem that could destroy a wheel…or worse. (I realize the OP is in the UK and doesn't have TPMSes.) Lastly, be sure you are checking/adjusting pressures before driving , when the tires are cold. Anyway, hope this helps.

Good topic, Zeus. I check tire pressures at least monthly…or before any planned spirited drive. I have not found the TPMS sensors to be very accurate, so I use an Intercomp tire pressure gauge. Hope that helps.

I check my 981 weekly if not driven, and about every other week if it's getting driven regularly. I'm checking with the digital reader on my Makita inflator (and topping up as needed). I'm also checking the in-dash readers every time I drive. For what it's worth the tires on my Macan S seem to need topping up more often than the tires on my Cayman even though they're driven about the same amount. Best of luck!

I check tire pressures every 2 weeks with a tire gauge when the tires are cold. Rarely do I look at the TPMS unless i suspect a leak.

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I used to have to check pressures every 2-3 weeks once. It was a bother and messy wiping up after (brake dust, dirt on wheel caps etc) Fast forward to an aftermarket TPMS and nitrogen gas fill ups and I now only need to top up once every 3 months and the TPMS can help monitor the situation in case of emergencies. In the last convoy drive we did covering about 2000kms (1200 miles), we did find that having a TPMS is useful for safety purposes being able to detect leaks and signal potential issues before they became major. highly recommended to get one. link for the aftermarket TPMS (not plugging any particular brand - there are so many to choose from now) #12

I check a few times a season.

Are you finding a different between your gauge reading and the cars' reading? I test in Consumer Reports a number of years ago found the stick tire pressure gauges were the most accurate. Don't remember the brand but I had them. They were metal; not sure you can buy a metal gauge anymore.

I don’t think the onboard pressure reading is as accurate as a guage.. Imo

Mine are within 1 psi.

Same with both my original sensors and the replacement Huf after ten years.

I have a digital gauge that's part of the hose from my compressor - probably from Harbor Freight . I find it agrees exactly with the display on both my Cayenne and my Boxster . Exactly the same reading... so I sort of trust it. The biggest thing in tire pressures is not the absolute pressure - it's getting them balanced left to right, and then the differential between front and rear... ie - both fronts at 30PSI, both rears at 34PSI (what I use on the Boxster , seems to work well.)

Why higher in the rear?

Pressures recommendations changed as new model year cars came out. For example, my 2008 with 19 inch wheels calls for 32 lbs. front and 36 lbs. rear. Those are the factory recommended pressures. As later models came out, it's safe to assume suspensions changed as did associated tire pressure recommendations. They're surprisingly different.

Or maybe the higher pressures increase mpg. All cars calling for higher pressure lately.

Not to hijack, but the 987 recommended PSI is when cold, correct? I keep the TPMS on while driving and was surprised how much PSI increased as the tires warmed up.

Recommended tire pressures are always for cold tires .

You can drive yourself crazy trying to "optomize" tire pressures. I spent a morning at Watkins Glen as the one man crew for a guy with a 944. He'd go out in practice and try different tire pressures until he found the ones that gave him the best lap times. I'm sure they were good for that car at that track in those weather conditions with the moon in it's third phase! The ones on the door placard certainly are a compromise of a variety of factors but they are the there and easy to implement. Not mentioned but as you go from summer to fall to winter, you need to keep re-setting your cold tire pressures. At the track, I've had my pressures change by 1 or 2 psi just based on which side of the car was facing the morning sun. Some of my cars with throw a dash low pressure warning as the days get cold, as the pressures can drop by more than 4 psi.

The question is - how cold? 32F, 70F, 100F? I generally figure on 72F based on something I heard decades ago that I've carefully consigned to the bit-bucket in my head never to be seen again. Pressure will go up and down with temperature. 1 PSI per 10 degrees F? Maybe. Depends. Nitrogen does a bit less since it doesn't have moisture in it (and moisture causes a greater change in pressure, at least that's what the nitrogen guys tell us..) On a motorcycle tire - much smaller volume - the difference can be more extreme. Or not. Tire pressures = vodoo -- which is why I always fill mine 2PSI higher than the sticker tells me to. It makes me feel good. That's what counts.

I remember reading somewhere related to tracking that when pushing the car you did not want the tires to go above 36psi. On my spirited drives in the winter I get to about 33 and in the summer I get to 36 with starting pressures at 29-30. Not sure how true this is. But so far the car has preformed very well.