What is the proper tire inflation for new TDI?

Nellie

Veteran Member
Joined
Jun 24, 2005
Location
Los Angeles, California
TDI
Jetta Wagon GLS, '05
Can anyone tell me what the proper tire pressure should be for my new '05 Jetta Wagon TDI? The sticker says 36 front 45 rear. The Conti tires say max 44 psi and the dealer recently adjusted all of them to 32 psi during the 5,000 mile service. Who's right?
Thanks,
Nellie
 

Ed's TDI

Top Post Dawg
Joined
Jan 30, 2001
Location
Victoria, BC, Canada
TDI
2001 Bora and 2016 Touareg
The ratings on the tire are just suggetions and the max is for whenever you pile a ton of cr@p in the trunk. If you rode around with 44psi in the rear, you'd find the ride pretty rough (although it isn't that bad when you're riding on 15" with a 65% aspect ratio!). For the best fuel economy, I found keeping the tires around 38psi was a good number. I ran the same tire pressure on my 17" Long Beach mags and still run 38psi with my 18" OZ's.

On a side note, I check the tire pressure each fillup and when I recently picked up a nail in the rear right tire, I noticed the ride was a bit off and it was because I noticed the varition in the tire pressure. The rear had dropped to about 26psi.
 

ruking

Top Post Dawg
Joined
Mar 27, 2003
Location
San Jose area, CA
TDI
2003 VW Jetta, 5 M, Reflex Silver: 09 Jetta, 6 Sp DSG, Candy White: 12 VW Touareg, 8 Sp A/T, Flint Gray
Can anyone tell me what the proper tire pressure should be for my new '05 Jetta Wagon TDI? The sticker says 36 front 45 rear. The Conti tires say max 44 psi and the dealer recently adjusted all of them to 32 psi during the 5,000 mile service. Who's right?
Thanks,
Nellie
You see the obvious "range of pressure" PSI.

I have run 85% of the max sidewall pressure (37.4 psi) or between 38-36 front and 2#'s less in rear 36-34 (to balance out the tremendous understeer, a bit) Also much above 38 psi is a bit harsh riding to my SOTP experience. One caveat here of course is: I operate this TDI in reputedly the worst roads in the nation. So if one has buttery smooth roads, then a couple of extra psi might not be as harsh. However the same still applies as to the performance curve of the tire. Toward max psi you have to be a bit hypersensitive to the center of the tread wearing faster. Also shock absorption is less with much higher PSI.

This seems to be best pressure for the performance curve for the recommended tires. So far on GY LS-H's, I am pushing 56,000 miles and project between 100-130 k miles.
 

tjl

Top Post Dawg
Joined
Mar 19, 2001
Location
California, USA
TDI
2001 Golf GLS
Can anyone tell me what the proper tire pressure should be for my new '05 Jetta Wagon TDI? The sticker says 36 front 45 rear. The Conti tires say max 44 psi and the dealer recently adjusted all of them to 32 psi during the 5,000 mile service. Who's right?
The number on the tire is the maximum inflation pressure for the tire. Seems like the factory made an error, installing 44psi maximum tires on a car that it recommends 45psi in. Note that all pressures are measured cold, before driving.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
Maybe the best pressure is the one that balances fuel economy with ride comfort without going out of bounds for what the tire states. If the tires are not original or the same as original, then it is best to go with what is on the tire.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
in my 05 i had 51 max psi tires (michelin energy mx4's). i run 43 front / 41 rear. but if they are 44 max psi, i would run 40/38.... but not higher. experiment. 38/36 would also be fine. i'm in the ~85% max pressure camp, with a couple extra lbs in the front
 

TornadoRed

Top Post Dawg
Joined
Aug 3, 2003
Location
West Des Moines (formerly St Paul)
TDI
2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
I would start with Ruking's suggestion -- set to 85% of the max PSI printed on the tire's sidewall. I would not go higher, as this could lead to premature wear in the center of the tread. If the ride is too harsh for you, drop down incrementally. But 85% is a reasonable starting point for maximum fuel economy and even tread wear.
 

burpod

teh stallionz!!1
Joined
Nov 27, 2004
Location
cape cod, ma
TDI
82 rabbit vnt ahu, 98 jetta vnt ahu, 05 parts car, 88 scirocco.. :/
not too mention if there if you fill your tires up when it's 55 degrees, and then a few days later it's 80 degrees, your tires will be waaay over-inflated. this happened to me. i had them at 44 and a few days later in much warmer weather they were well at around 51-52lbs
 

mailman

Veteran Member
Joined
Oct 30, 2002
Location
USA - CT
TDI
99.5 Black Jetta TDI
The correct tire pressure is the pressure that will result in a maxium tire contact area with the road. This pressure will wear the tires evenly and provide the safest ride with maximum traction available for braking and turning. Fuel economy and ride "feel" should not be the criteria.

That being said, the correct tire pressure for your particular vehicle will vary with ambient temperature, vehicle weight, and tire make/model.

Best way to determine if you have the correct pressure is to use a method that was recommended by a friend of mine. You'll need a piece of your child's sidewalk chalk for this test. In a parking lot with the car in its "usual" driving conditions (i.e., load, temperature, etc.), draw a chalk line across the tread of your tires. Get back in the car and roll the car 10-20 feet (enough for a few complete tire revolutions) and check the chalk marks. If the marks show even wear, then your tires are properly inflated. Simple.

If the chalk marks show more wear in the center of the tread, then your pressure is too high. If the chalk marks show wear on the outside edges of the tread, then your pressure is too low.

Remember to thank your child for lending his/her chalk.
 

tongsli

Top Post Dawg
Joined
Jan 31, 2000
Location
Baltimore, MD
TDI
2000 Jetta TDI, 2004, Jetta Wagon TDI PD
I've never had a dealership or tire service place put my tires any higher than 34PSi.
 

dieseldorf

Top Post Dawg
Joined
Oct 11, 2000
Location
MA
TDI
ex- 1996 wagon, ex-2000 Jetta
Can anyone tell me what the proper tire pressure should be for my new '05 Jetta Wagon TDI? The sticker says 36 front 45 rear. The Conti tires say max 44 psi and the dealer recently adjusted all of them to 32 psi during the 5,000 mile service. Who's right?

Nellie, for some reason the cars sent to the USA are showing only the MAX inflation pressures. The cars sent to Canada have complete info. This discussion was recently covered over here: web page
 

tongsli

Top Post Dawg
Joined
Jan 31, 2000
Location
Baltimore, MD
TDI
2000 Jetta TDI, 2004, Jetta Wagon TDI PD
Thanks DD,

I keep the front and rears and 32PSI. Most of the time, it's just two of us in the car.

L
 

xsfmed

Veteran Member
Joined
Jun 2, 2004
Location
Montana
TDI
Golf, 2002, Indigo Blue
I've had very good performance and wear on my Michelin Energy mX4's at right around 40psi - they're wearing evenly (rotate every 5-7.5 k), handling is good, mpg is ok (auto, can't do much), not too mushy, not too hard -- my .02
 

IndigoBlueWagon

TDIClub Enthusiast, Principal IDParts, Vendor , w/
Joined
Aug 16, 2004
Location
South of Boston
TDI
'97 Passat, '99.5 Golf, '02 Jetta Wagon, '15 GSW
I bet this is way more info than you wanted. Look at the inside of the fuel filler door--it should say at half load pressures are 28 front/26 rear. The pressures you recorded are for max load.

Everyone here will tell you that 28/26 is too low. Since VW wants the best possible ride they probably run the tires a bit soft. I usually use 30-32 in front and 28 in the rear. The pressure differential helps the ride in the rear (the rear of these cars when unloaded is much lighter than the front) and makes the car understeer a bit less.

Experts say "when in doubt go with 32psi." So your dealer did the right thing, more or less.
 

whitedog

Veteran Member
Joined
Jul 12, 2004
Location
Bend, Oregon
TDI
2004 Jetta that I fill by myself
32 PSI is probably a cheery psycic. A balance between ride comfort, handleing, fuel economy and tire wear. Without knowing what the customer is looking for, it's a good starting point.
 
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