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Discussion Starter · #1 ·
Went to the closest dealer for my first complimentary service. It was not the same dealer I purchased from and will be the last time I go there. On the way home the car was providing a harsher ride than normal. I checked the tire pressure and all were at 39-41 psi. Pulled off at next exit, found a gas station and let some air out of all tires. Got them all to about 36 and headed home. Checked the worksheet I was provided and it indicated they filled tires 36 front and 38 rear (while still warm!) as per specs. Called the service department when I got home to ask why. Service manager said sticker in door is generic and is only for safety compliance (WTF) and then instructed me to check the PCM for the correct pressure for the size and type of tire on the car because that's what they rely on. Ok, checked that and it recommended 30 rear, 29 front for the 19 inch summer tire just as the door sticker indicates. Tire pressure requires basic knowledge and the fact they did not know and got it wrong for all the wrong reasons would make me cautious to go back there for something more complicated. I'll adjust pressures tomorrow when they are cold. Oil level was a little low but still in the correct range. Anyone in central-Florida area wanting details can pm me.
 

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I have never, ever, had a dealer, garage or tyre shop EVER set tyre pressures correctly.

Even at Porsche Leeds about 6 weeks ago, my first service at 13500 miles the tyre pressures were ‘perfect’ at 30psi all round (20” summers) when it went in, as per the user guide and the door sticker.

They were perfect untiI I checked at home to find the ‘expert technician’ had increased them all round to 35+.

Why did I check them? For the reasons above - they just don’t care enough to be bothered, bang them up to late 30’s and let it go. Very few people will check!
 

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I have never, ever, had a dealer, garage or tyre shop EVER set tyre pressures correctly.

Even at Porsche Leeds about 6 weeks ago, my first service at 13500 miles the tyre pressures were ‘perfect’ at 30psi all round (20” summers) when it went in, as per the user guide and the door sticker.

They were perfect untiI I checked at home to find the ‘expert technician’ had increased them all round to 35+.

Why did I check them? For the reasons above - they just don’t care enough to be bothered, bang them up to late 30’s and let it go. Very few people will check!
I thought I remember the 20" summer wheels/tires having a recommended pressure of 33 PSI for standard street driving.

Isn't 30 PSI for 18" summer wheels/tires?

I tried to find the on-line owner's manual, but it looks like it has been removed from the Porsche website for the time being. I have the chart printed out at my other office but won't be back there until next week.

Maybe 30 in lieu of 33 is for the comfort setting?
 

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@jns211, I think (from memory) that you are correct.

I have to agree that tire pressures aren't the strong point of most shops. We users are usually more compulsive about it than shops. The shop guy doesn't know whether you want a comfort or performance setting, nor will he necessarily look at the label to see if the tires are summer or winter.

It isn't really so critical anyway unless you are on the track. Pressures go up and down with temperature as you are driving. The nice thing about the TPMS display is it shows you the actual reading on each tire. That's much better than the systems which just show a warning light "low tire" with no other information. It is more or less the driver's responsibility to set pressures as desired. But getting them exactly right is like trying to adjust your lawn furniture to accommodate the wind. It's always changing.
 

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FYI, according to the Good to Know app, 18" 29 psi front and rear; 19" 29 front 30 rear; and 20" 33 psi both front and rear. I generally start my 18" at 29 psi (in cooler temps, it could be 28 psi) but by the time I get home they are usually in the 31 psi range. So, these are cold summer tire pressures.
 

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Discussion Starter · #6 ·
FYI, according to the Good to Know app, 18" 29 psi front and rear; 19" 29 front 30 rear; and 20" 33 psi both front and rear. I generally start my 18" at 29 psi (in cooler temps, it could be 28 psi) but by the time I get home they are usually in the 31 psi range. So, these are cold summer tire pressures.
Exactly. So how did the dealership determine that the specs on a 19 tire required 36/38? None of the stock tires provided on 718s are anywhere near that. The tires are rated to max 50 psi so failure was not the issue, more of tire wear from over-inflation.
 

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No one sets the tire pressure properly. Not the dealers, not the indie shop I do the intermediate oil changes. They tend to put crazy pressures in 39-41. Thankfully I have an electronic pressure gauge which agrees with the pressure sensors and the air system at Discount Tire, so I go home and re-set pressures next morning, when the tires are cold. I also have an air pump if needed.
 

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Discussion Starter · #8 ·
I'll accept the fact that tires are not inflated properly everywhere. But, how can one justify that a dealership pulled "spec" numbers for tire pressure that just are not correct. Not to mention they inflated tires while they were obviously still warm from my trip to the dealership. Just makes me wonder how special Porsche service really is for the price they charge. I could get that kind of service/outcome at Jiffy Lube. Yeah, I know, they'd take it out for a spin, scratch it, leave the oil plug out..l., but not Porsche.
 

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I'll accept the fact that tires are not inflated properly everywhere. But, how can one justify that a dealership pulled "spec" numbers for tire pressure that just are not correct. Not to mention they inflated tires while they were obviously still warm from my trip to the dealership. Just makes me wonder how special Porsche service really is for the price they charge. I could get that kind of service/outcome at Jiffy Lube. Yeah, I know, they'd take it out for a spin, scratch it, leave the oil plug out..l., but not Porsche.
Ask them to show you where these values came from. You can also point out that both your door tag and owners manual (I think it's there) shows something totally different.
I would expect much more from them and you should make sure they understand your view.

Whenever any of my cars go in for service, I tell the dealer "don't adjust tire pressure, don't rotate my tires, don't retorque the wheels." If they need to take the wheels off, then I tell them I expect they will use a torque wrench to set them all at the correct value. Why? Because I've been down that path too many times. Story: a VW dealer rotated my wife's tires for her. They obviously used an air gun to put them back on as they were torqued to around 180lbs+. Yes, that is correct - 180lbs. I was ripped when I discovered what they had done. I was on crutches due to a torn Achilles, and just the act of determining that the torque was way higher than it should be was difficult. That really p'ed my off. Contacted the dealer and they said no way, we know it was done right. My wife & I drove 1 hour back just so they could prove to me that they had set the torques correctly. That didn't happen. Once they realized that 180lbs was about the nominal setting, instead of saying this is unacceptable and we'll make it right they instead went into the song and dance that we did not do this and oh yes, they can tighten up on their own as you drive your car. Un-freaking-believable! That was the day they lost a customer, which was too bad because we liked them in a lot of ways.

Experiences like this is why I really, really hate going to dealers. Once I find a good one though, I'm theirs for life unless they screw it up.

MOO
 

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Discussion Starter · #10 ·
I responded to their "how was our service" text today and told them as much. I won't be going back. Several more to chose from in reasonable commuting distance so no worries. I'll be online to provide a review for them as well. I don't want to spend any more time trying to correct their obvious deficiencies. Moving on.
 

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I thought I remember the 20" summer wheels/tires having a recommended pressure of 33 PSI for standard street driving.

Isn't 30 PSI for 18" summer wheels/tires?

I tried to find the on-line owner's manual, but it looks like it has been removed from the Porsche website for the time being. I have the chart printed out at my other office but won't be back there until next week.

Maybe 30 in lieu of 33 is for the comfort setting?
You’re correct in that 20” summer comfort is 30psi all round as stated on door sticker and in the Good to Know, picture attached. 33psi is indeed the standard pressure setting
Comfort is for speeds up to 165mph, so I guessed that as I’m unlikely to travel routinely at 165 then comfort at 30psi is the ‘correct’ setting for me.
All four tyres btw have worn very evenly over 14k miles.
Text Line Font Number Parallel
 

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Tyre pressure seems to be s strong point at my dealer. When I bought the car the pressures were spot on (comfort setting). Since then it has been in twice - once for it's first service (again the tyres were spot on); and once for a pre-track day inspection at which they increased the pressure to the standard pressure. At the track day (organised by the dealer) they had a technician present who checked and adjusted the tyres after every run and then again before we left for the drive home. They also told us to check our pressures again in the morning and if there were any issues to bring it in the dealer for checking. I checked in the morning and mine were exactly where they should be. I was impressed.
 
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