02_996_C2

I was washing my father's new '02 Passat 1.8T wagon this morning. When I was drying off the gas door, I found the following info regarding the tire pressures. I think it is useful to everyone here. I also check the tire pressures on the Passat to compare it with the factory recommended numbers. I bought the Passat about 2 weeks ago as the father's day gift and it was built in APR/02. Then, I also look into the factory tire pressure decals on my 996, my brother's 986 S, & my wife's '00 X5 4.4 sport pkg.

Here's the info:

BMW X5 (255/285-F/R) F R
19" tires full load 36 39

Passat (195/65R15 tires) full load 1050lbs
<100 miles & half load 28 28
<100 miles & full load 30 39
100+ miles & half load 30 28
100+ miles & full load 33 42
ACTUAL TIRE PRESSURES 32.5 32.5

996
750lbs load (4 persons) 36 44
TIRE PRESSURE 32 32
WHEN DELIVER

986S
529lbs load (2 persons) 29 36

So, I guessed the tire pressures are related to the vehicle weight and speed of course. But from what I have seen on the 986, the car should not need anything more than 36 at 2 persons of load. I am driving my 996 with ONLY myself in most of the time, so, that's why I found 32/34 on my car is the best setup.

I think the only reason why PORSCHE recommends such a high tire pressure is because of the vehicle load assumption.

Hope these can help you guys to figure out your optimal tire pressures, Cheers!


<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Greg Fishman

Lawrence,
what is actually in the car means nothing, zilch.
Just because the dealer didn't prep the car correctly doesn't mean that pressure is what the car should have.
Greg

Viken

Actually, this is even more interesting. The Ferrari 360 Modena is outfitted at the factory with four different tires. The company provides a dedicated door plaque for each with a different set of pressures for each.

- Goodyear Eagle F1 Fiorano: 32F / 32R
- Pirelli P-Zero System: 32F / 29R
- Bridgestone Potenza S02A: 32F / 32R
- Michelin Pilot Sport: 26F / 28R

Gee, I wonder why a car manufacturer would go through the trouble of recommending such ridiculously low pressures let alone different ones for different tires.

Palting

[quote]Originally posted by 02_996_C2:
<strong>

996
750lbs load (4 persons) 36 44
TIRE PRESSURE 32 32
WHEN DELIVER

</strong><hr></blockquote>

Hmmmmm? 4 people in a 996, total weight 750 lbs. That's 187 lbs each. Two 187 pounders in the back seat. Hmmmmmmm. Pretty dense people. Either that or two 375 pounders in the front seat. Hmmmmmmm. German test subjects must be as big as summo wrestlers.

02_996_C2

Greg, I don't agree with you! I strongly believed the germans prep their cars as close to spec as possible when they roll out of the assembly line. Especially you are talking about a Porsche, BMW & VW, these are the best quality vehicles in the world. Have you ever come to a VW ad that shows you how VW engineerers managed to get the doors on all VW cars as close to each other as possible? I strongly think the tire pressures on all Porsches are pumped in certain specs according to the factory. This is shown in my '02 996 C2 & my bro's '01 986S!

Even Ferrari recommends some realistic numbers on their tire pressures according to VIKEN.

Well, your assumption may be correct on a FORD! <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Viken

[quote]Originally posted by 02_996_C2:
<strong>Greg, I don't agree with you! I strongly believed the germans prep their cars as close to spec as possible when they roll out of the assembly line. Especially you are talking about a Porsche, BMW & VW, these are the best quality vehicles in the world.</strong><hr></blockquote>

I have purchased more than a few dozen German cars in my life and have never taken delivery of a car which had cold pressures set at factory specs. Most of them were much lower and none was consistent throughout the same axle. My guess is, even if the factory sets the right pressures, it changes throughout the course of the time it takes for the car to reach PDI and the dealer. Furthermore, neither PDI nor the dealer spends the time to reset the pressures. My overall impression of German cars is that they may be some of the finest driving vehicles but quality ain't there.

[quote]<strong>Have you ever come to a VW ad that shows you how VW engineerers managed to get the doors on all VW cars as close to each other as possible?</strong><hr></blockquote>

No, but they never are that way on any German car.

02_996_C2

VIKEN, every manufacturer has their range of tolerances in production. German cars may not be the most consistence in terms of quality control, however, they are among the best. I have owned so many different brands of cars including LEXUS, TOYOTA, HONDA, NISSAN and all german brands, the most reliable/consistence in quality car I have ever had is not from any of the Japanese manufacturers either. I think this is depend on your luck. But I strongly believes German cars are among the best.

Tire pressures may be off when you get your vehicle delivered from the dealer. That's why I look at the production date as a reference too. Our 996 & Passat were delivered to us right after it was built (within 2 months of production date).

Look closely to other vehicles on the market and you will see how well the german cars were built!

The built quality on the Ferraris & Lambos are even worse...

Loren

Here is some interesting stuff I found in the Porsche (Technical Manual) documentation:

Recommended tire pressures:

Carrera Coupe (18x7.5 and 18x10 wheels)
Front: 36 psi(2.5 bar)
Rear: 44 psi (3.0 bar)
We already knew this but here is the interesting part...

GT3 Coupe (18x8 and 18 x 10 wheels)
Front: 32 psi (2.2 bar)
Rear: 39 psi (2.7 bar)
No rear seats just a little heavier than a regular coupe (2977 lbs vs. 2917 average weights).

Interesting... that Porsche would recommend lower pressures for a car only available in Europe. Sounds like more of the same old US drivers can't handle ROW M030 or lower tire pressures??? Hmmm...

ohsixx

Palting: Now wait just a minute. I am 6'2" and weight 187 pounds, so I am dense?

My current car is about 200 pounds less than a C4S and the recommended cold pressure is 30psi.

I will probably go with something like suggested above - 32/34 cold.

Viken

[quote]Originally posted by 02_996_C2:
<strong>The built quality on the Ferraris & Lambos are even worse...</strong><hr></blockquote>

I happen to have one of them in my garage next to two German cars, care to know how it compares? Also, have you seen a Murciélago up close? Most likely not since you think the build quality doesn't measure-up.

Jims02C2

I can assure you that no car comes from the factory with with tire pressure set exactly as it should be, especially cars that have to make the long trip over the Atlantic and then maybe sit on a dealer's lot for a while. Every manufacturer sets their tire pressures very high from the factory to help prevent flat-spotting for the 3+weeks they will be required to sit in the ship or at the port of entry. When the technician at the dealership does the PDI (Pre-Delivery Inspection) on a vehicle he is supposed set the tire pressures according to the manufacturers recommendations. Working with technicians on a daily basis, I can tell you that happens alot less than you would think. Even if they do, their gauges might not have been calibrated in a while and most use the ones like you see at gas stations. Some technicians even think they know better than the factory and set them to what they think is right.

Someone said it best on the list previously...the correct tire pressure is going to be the one that is right for that day. One that takes all the variables into account, such as vehicle load, ambient temp, suspension set up, alignment, etc..

If you are tracking the car, then the best way to tell is a pyrometer. This measures the heat build-up in the tire and will be a good indicator if your pressures are set correctly.

If you are just street driving, then it becomes a matter of what you prefer (as long as you don't go out of the range of safety). Do you want gas mileage? Ultimate grip? smoother ride? On the street the best indicator is tire wear pattern. In general if they are wearing on the inside and outside edges, they are underinflated. If they are wearing more in the center, they are over-inflated.

02_996_C2

Excuse me VIKEN, isn't Murciélago a German & Italian venture? When I said Lambo means the Diablo & Countach. Eveyone knows the Murciélago has the AUDI like interior & built quality, but guess what? another german owned car company!

I knew you have a 360 in your garage. I have compare a 360 & a leathered 996 interior, 996 is still better in terms of built quality. Don't get me wrong, the design of the 360 looks better than the 996 inside & out. But I am talking about built quality, not design!

German built vehicles - may not be the very best, but simply among the best!

Viken

[quote]Originally posted by 02_996_C2:
<strong>Excuse me VIKEN, isn't Murciélago a German & Italian venture? When I said Lambo means the Diablo & Countach. Eveyone knows the Murciélago has the AUDI like interior & built quality, but guess what? another german owned car company!</strong><hr></blockquote>

Oh, I didn't realize you were comparing some cars from a past era with the present era German cars. Sorry about that.

[quote]<strong>I knew you have a 360 in your garage. I have compare a 360 & a leathered 996 interior, 996 is still better in terms of built quality. Don't get me wrong, the design of the 360 looks better than the 996 inside & out.</strong><hr></blockquote>

<img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" /> <img src="graemlins/a_smil17.gif" border="0" alt="[blabla]" />

[quote]<strong>But I am talking about built quality, not design!</strong><hr></blockquote>

Me too.

bloke

Viken,

Wassup! Very unlike yourself. No need for petty arguements. Let them drive at whatever pressure they want.

But for me, I do thank you for all the infomation I have gotten on my car.

Thanks and keep up the good work.

Viken

[quote]Originally posted by bloke:
<strong>Wassup! Very unlike yourself. No need for petty arguements. Let them drive at whatever pressure they want.</strong><hr></blockquote>

Petty arguments? Where?