Is tire pressure based on the car or the tire?

 

I have those same tires in the 18" rim size and run the factory 41 psi all around, The tires seems to wear very evenly if you rotate back to front every 10,000 miles. I'm a little surprised at the different front and back pressures that you quoted. I really like the tires, I have 30,000 miles on them currently and they will easily go another 10,000 if not 15,000 before I will need to change them.

 

Yeah, I'm confident the tires are quality based on all the great feedback, but VW states right on the label to run the rears @ 46 PSI but these tires are only rated @ 44 PSI MAX. Which makes me queasy to pull the trigger on them.

Again, this is for the stock 255/60/17 setup.

 

Run them at 44. I have Hankooks with the same issue and run the backs at 44, No problem. Towing a travel trailer on the HOT Arizona highways, the pressure goes up to 50+ pounds anyway from the heat buildup.

 

I figured that would be the best option. The other tire I'm looking at is the Continental CrossContact LX which is rated for 51 PSI which makes me think it is a better fit... but not as many glowing reviews of it on here.

 

I was also both over/underwhemed by the segment. I called T/R and the C/S type who helped me indicated that the C CC LX 20 excited T/R.com testers.

I think the real problem is our vehicle and tire category is SO specialized and limited. To boot, individual applications can be even more rarified. When you combine that with the VW Tourareg user/owners' population being very small, it is harder to throw out extreme ratings either for or against. I have also noticed on places like Tirerack.com (VW T owners probably also fit the profile), there is a decided bias against most oem tires. Indeed to a certain extent, one might be remiss in ignoring that bias. On the other hand, if someone really LIKES/DISLIKES another tire (non oem) you really have to weight that against the all sorts of metrics, it never had to pass to be an oem tire. Again that person is normally one to maybe several of a very few that has tried that tire to (our) VW T application. In the context of things, VW T's production of 2011 was 7,535 units. When you factor in the (unpublished) % (rumored to be 22%) and number of diesels, it gets even MORE rarified (1,618 units) What might be one big deal here? TDI's 406# ft of torque applied cowboy style vs gasser @ 265 # ft, and hybrid of 428# ft. To say that these three variables do not affect the opinion/s would be ignoring the obvious differences.

So here is an obvious issue. The Bridgestone you selected has (in other applications) has been rated a very good to excellent tire. However it is as you say a max side wall pressure of 44 psi. By and in of itself no harm no foul. However as you rightly noted, VW T/P recommendations indicate that 51 psi max side wall is one metric and or specification. So for example on the 2012 VW T TDI the oem recommended T/P is 33/38. on a 51 psi side wall set of oem tires or 65% F/80% R of maximum side wall T/P . Further the oem owners manual makes reference to running 3# psi MORE 36/41 PSI.

 

Where did you find that number for diesel Touareg production?

I would have thought the majority were diesels rather than a minority.

 

I read the gross figure off a VW web site. The 22% (actually 21.8%) percentage diesel figure was read in passing, an article written sometime after the 2011 figures were in. VW does mention OVERALL TDI figures of app 23%, but that can be slightly misleading for a smaller run like the T. As an example, 86% of VW Jetta Sport Wagons were TDI's diesel, but the JSW was a way smaller run than Jetta SEDANS.

I shot an email to VW to get their VW T TDI figures, but they have yet to reply.

Correction: 38/51 PSI= 75% of maximum side wall pressure. 41/51 PSI= 80% of maximum side wall pressure.

 

Just checked both the door/tire pressure label as well as the manual for my 2007 Treg V6 gasser. It states 36 front and 44 rear.

Also checked my 255/60/17 tires. Although they are rated 106V, with a max. psi of 51, they have the same load rating (2,094#) as the Alenza. Which seems to imply the Bridgestones require less psi to achieve a similar load rating. Other differences: Alenzas weigh 37#s and have a tread depth of 13/32nds. Mine weigh 33#s and begin life with a tread depth of 10/32nds.

You should be okay at 44# unless you are driving over 130 mph for more than ten minutes...or have a castastrophic collision and someone sues you on the basis of your negligence: you had installed inadequate tires that failed to meet OEM psi spec, which resulted in a rollover or blow-out, resulting in a loss of control.

 

Thanks. Should note this is a 2008 Touareg 2 VR6; based on the comment above about the 2007 I guess the '08 T-2 has different specs (slightly).

 

For the tires it all comes down to the Extra Load (XL) rating of the tire. I think this is called "Reinforced" in some places. The Wikipedia explanation is that the XL tires can be inflated to higher pressures and therefore carry higher loads - i.e., beyond the loads listed in the table, which are at a lower pressure.

A similar but different explanation is provided by Nokian Tires, saying that the XL tires allow for an actual load of four (load) units higher. Nokian then says that this has to do with heavy vehicles that are capable of higher speeds. I interpret this to mean that a 109XL load rating x-speed rated tire is as capable as a 113 load rating tire with the same speed rating (x). So why would I want a 109XL when a 113 would be just as good? My interpretation is that the 113 tire might be stiffer or have some other negative characteristic for the way my vehicle drives. Similarly, getting a straight 109 tire (not XL) would likely handle most loads... but maybe I'd need to be concerned about emergency avoidance manoeuvres and handling.

Any reputable tire shop will tell you to get at least the minimum load and speed ratings recommended by the vehicle manufacturer. My search of TireRack for 18" tires didn't come up with any tires that were less than 109XL load rating or S for speed rating (112 mph or 180km/h). For the sake of a few dollars (on an already expensive vehicle), I don't see why you'd settle for lower specifications.

 

For the sake of a few dollars (on an already expensive vehicle), I don't see why you'd settle for lower specifications.

Totally agree. My basic point is that it seems like half the tires listed as compatible on a search like this are actually not capable of holding the pressure that the OEM label calls for. Both tires I have mentioned are at the upper-end of the price bracket, so this situation isn't really about dollars but really details.

At this point I think I'm going to go with the tires that are rated to 51 PSI, inflate to the full pressures recommended and call it a day. It's a shame because the Alteza tires are so highly recommended, but I think this is the right choice.

 

If you havn't already, check out the Toyo Proxes S/T II in 255/60/17. It has max psi of 50 and a 110V rating. It is shown on the Toyo web page, but not listed at Tirerack.

 

http://tirefinder.toyotires.com/?vid=40120

Toyo lists 4 tires 3 V rated and one H rated. 2 with the XL rating. Versado CUV seems to top the list.

Now I have had great experiences with Toyo tires, but in (3) FAR different applications.

 

The link to Wiki makes for interesting reading for those who want to learn more about tires.

So does the link to Tire Rack's info pages and not just the one here:

Tire Tech Information - How to Read Speed Rating, Load Index & Service Descriptions

 

After a month on the new Continental CrossContact LX tires I can say that I am extremely impressed. As I mentioned earlier the Dunlops that were on the car were severely cupped and extremely noisy. The new tires are like driving on air and the Touareg is once again a serene environment. Of course any new tire would seem nice at this point since the Dunlops were in such bad shape, but the Contis look great on the car and it is nice knowing I can put a full 46 PSI cold in the rear and not worry about temperature fluctuation and being over-inflated. Can't wait for some decent snow to really try them out and anxious to see how long they'll last with their 750 tread-wear rating.

 

Very! Been a great tire. Quiet, holds pressure well, no wear problems, and the tread fits the attitude of the Touareg.

Thanks man for the quick reply. I'm also looking at Pirelli Scorpion Verde & Conti DWS.